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Paul E. McKenney2e24ce82019-01-17 10:16:42 -08001// SPDX-License-Identifier: GPL-2.0+
Paul E. McKenneya241ec62005-10-30 15:03:12 -08002/*
Paul E. McKenney29766f12006-06-27 02:54:02 -07003 * Read-Copy Update module-based torture test facility
Paul E. McKenneya241ec62005-10-30 15:03:12 -08004 *
Josh Triplettb772e1d2006-10-04 02:17:13 -07005 * Copyright (C) IBM Corporation, 2005, 2006
Paul E. McKenneya241ec62005-10-30 15:03:12 -08006 *
Paul E. McKenney2e24ce82019-01-17 10:16:42 -08007 * Authors: Paul E. McKenney <paulmck@linux.ibm.com>
Josh Triplette0198b292014-07-30 16:08:42 -07008 * Josh Triplett <josh@joshtriplett.org>
Paul E. McKenneya241ec62005-10-30 15:03:12 -08009 *
Mauro Carvalho Chehab43cb5452020-04-21 19:04:06 +020010 * See also: Documentation/RCU/torture.rst
Paul E. McKenneya241ec62005-10-30 15:03:12 -080011 */
Paul E. McKenney60500032018-05-15 12:25:05 -070012
13#define pr_fmt(fmt) fmt
14
Paul E. McKenneya241ec62005-10-30 15:03:12 -080015#include <linux/types.h>
16#include <linux/kernel.h>
17#include <linux/init.h>
18#include <linux/module.h>
19#include <linux/kthread.h>
20#include <linux/err.h>
21#include <linux/spinlock.h>
22#include <linux/smp.h>
Paul E. McKenney9cf8fc62020-03-06 14:00:46 -080023#include <linux/rcupdate_wait.h>
Paul E. McKenneya241ec62005-10-30 15:03:12 -080024#include <linux/interrupt.h>
Ingo Molnar174cd4b2017-02-02 19:15:33 +010025#include <linux/sched/signal.h>
Ingo Molnarae7e81c2017-02-01 18:07:51 +010026#include <uapi/linux/sched/types.h>
Arun Sharma600634972011-07-26 16:09:06 -070027#include <linux/atomic.h>
Paul E. McKenneya241ec62005-10-30 15:03:12 -080028#include <linux/bitops.h>
Paul E. McKenneya241ec62005-10-30 15:03:12 -080029#include <linux/completion.h>
30#include <linux/moduleparam.h>
31#include <linux/percpu.h>
32#include <linux/notifier.h>
Paul E. McKenney343e9092008-12-15 16:13:07 -080033#include <linux/reboot.h>
Rafael J. Wysocki83144182007-07-17 04:03:35 -070034#include <linux/freezer.h>
Paul E. McKenneya241ec62005-10-30 15:03:12 -080035#include <linux/cpu.h>
Paul E. McKenneya241ec62005-10-30 15:03:12 -080036#include <linux/delay.h>
Paul E. McKenneya241ec62005-10-30 15:03:12 -080037#include <linux/stat.h>
Paul E. McKenneyb2896d22006-10-04 02:17:03 -070038#include <linux/srcu.h>
Robert P. J. Day1aeb2722008-04-29 00:59:25 -070039#include <linux/slab.h>
Paul E. McKenney52494532012-11-14 16:26:40 -080040#include <linux/trace_clock.h>
Harvey Harrisonf07767f2008-10-20 10:23:38 -070041#include <asm/byteorder.h>
Paul E. McKenney51b11302014-01-27 11:49:39 -080042#include <linux/torture.h>
Paul E. McKenney38706bc2014-08-18 21:12:17 -070043#include <linux/vmalloc.h>
Paul E. McKenney0032f4e2017-08-30 10:40:17 -070044#include <linux/sched/debug.h>
Joel Fernandes (Google)450efca2018-06-10 16:45:43 -070045#include <linux/sched/sysctl.h>
Paul E. McKenneye0aff972018-10-01 17:40:54 -070046#include <linux/oom.h>
Paul E. McKenneyd38e6dc2019-07-28 12:00:48 -070047#include <linux/tick.h>
Paul E. McKenneyc1a76c02020-03-10 10:32:30 -070048#include <linux/rcupdate_trace.h>
Wander Lairson Costa5ff7c9f2021-11-10 11:37:45 -030049#include <linux/nmi.h>
Paul E. McKenneya241ec62005-10-30 15:03:12 -080050
Paul E. McKenney25c36322017-05-03 09:51:55 -070051#include "rcu.h"
52
Paul E. McKenneya241ec62005-10-30 15:03:12 -080053MODULE_LICENSE("GPL");
Paul E. McKenney2e24ce82019-01-17 10:16:42 -080054MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com> and Josh Triplett <josh@joshtriplett.org>");
Paul E. McKenneya241ec62005-10-30 15:03:12 -080055
Paul E. McKenney2397d072018-05-25 07:29:25 -070056/* Bits for ->extendables field, extendables param, and related definitions. */
Paul E. McKenney1c3d5392021-09-22 20:49:12 -070057#define RCUTORTURE_RDR_SHIFT_1 8 /* Put SRCU index in upper bits. */
58#define RCUTORTURE_RDR_MASK_1 (1 << RCUTORTURE_RDR_SHIFT_1)
59#define RCUTORTURE_RDR_SHIFT_2 9 /* Put SRCU index in upper bits. */
60#define RCUTORTURE_RDR_MASK_2 (1 << RCUTORTURE_RDR_SHIFT_2)
Paul E. McKenney2ceebc02018-07-06 15:16:12 -070061#define RCUTORTURE_RDR_BH 0x01 /* Extend readers by disabling bh. */
62#define RCUTORTURE_RDR_IRQ 0x02 /* ... disabling interrupts. */
63#define RCUTORTURE_RDR_PREEMPT 0x04 /* ... disabling preemption. */
64#define RCUTORTURE_RDR_RBH 0x08 /* ... rcu_read_lock_bh(). */
65#define RCUTORTURE_RDR_SCHED 0x10 /* ... rcu_read_lock_sched(). */
Paul E. McKenney1c3d5392021-09-22 20:49:12 -070066#define RCUTORTURE_RDR_RCU_1 0x20 /* ... entering another RCU reader. */
67#define RCUTORTURE_RDR_RCU_2 0x40 /* ... entering another RCU reader. */
68#define RCUTORTURE_RDR_NBITS 7 /* Number of bits defined above. */
Paul E. McKenney2ceebc02018-07-06 15:16:12 -070069#define RCUTORTURE_MAX_EXTEND \
70 (RCUTORTURE_RDR_BH | RCUTORTURE_RDR_IRQ | RCUTORTURE_RDR_PREEMPT | \
71 RCUTORTURE_RDR_RBH | RCUTORTURE_RDR_SCHED)
Paul E. McKenney2397d072018-05-25 07:29:25 -070072#define RCUTORTURE_RDR_MAX_LOOPS 0x7 /* Maximum reader extensions. */
73 /* Must be power of two minus one. */
Paul E. McKenneyc116dba2018-07-13 12:09:14 -070074#define RCUTORTURE_RDR_MAX_SEGS (RCUTORTURE_RDR_MAX_LOOPS + 3)
Paul E. McKenney2397d072018-05-25 07:29:25 -070075
Paul E. McKenney2397d072018-05-25 07:29:25 -070076torture_param(int, extendables, RCUTORTURE_MAX_EXTEND,
77 "Extend readers by disabling bh (1), irqs (2), or preempt (4)");
Paul E. McKenneycb506e12022-04-17 20:43:13 -070078torture_param(int, fqs_duration, 0, "Duration of fqs bursts (us), 0 to disable");
Paul E. McKenney9e250222014-01-27 16:27:00 -080079torture_param(int, fqs_holdoff, 0, "Holdoff time within fqs bursts (us)");
80torture_param(int, fqs_stutter, 3, "Wait time between fqs bursts (s)");
Paul E. McKenneycb506e12022-04-17 20:43:13 -070081torture_param(int, fwd_progress, 1, "Number of grace-period forward progress tasks (0 to disable)");
Paul E. McKenney1b272912018-07-18 14:32:31 -070082torture_param(int, fwd_progress_div, 4, "Fraction of CPU stall to wait");
Paul E. McKenneycb506e12022-04-17 20:43:13 -070083torture_param(int, fwd_progress_holdoff, 60, "Time between forward-progress tests (s)");
84torture_param(bool, fwd_progress_need_resched, 1, "Hide cond_resched() behind need_resched()");
Paul E. McKenneya48f3fa2014-03-18 15:57:41 -070085torture_param(bool, gp_cond, false, "Use conditional/async GP wait primitives");
Paul E. McKenney11d62f02022-02-01 07:01:20 -080086torture_param(bool, gp_cond_exp, false, "Use conditional/async expedited GP wait primitives");
Paul E. McKenneyb6fe4912022-08-04 13:46:05 -070087torture_param(bool, gp_cond_full, false, "Use conditional/async full-state GP wait primitives");
Paul E. McKenney8df13f02022-08-04 15:23:26 -070088torture_param(bool, gp_cond_exp_full, false,
89 "Use conditional/async full-stateexpedited GP wait primitives");
Paul E. McKenney9e250222014-01-27 16:27:00 -080090torture_param(bool, gp_exp, false, "Use expedited GP wait primitives");
Paul E. McKenneycb506e12022-04-17 20:43:13 -070091torture_param(bool, gp_normal, false, "Use normal (non-expedited) GP wait primitives");
Paul E. McKenney0fd05482020-11-13 20:43:59 -080092torture_param(bool, gp_poll, false, "Use polling GP wait primitives");
Paul E. McKenney11d62f02022-02-01 07:01:20 -080093torture_param(bool, gp_poll_exp, false, "Use polling expedited GP wait primitives");
Paul E. McKenney76ea3642022-08-02 17:04:54 -070094torture_param(bool, gp_poll_full, false, "Use polling full-state GP wait primitives");
Paul E. McKenney6c502b12022-08-03 12:38:51 -070095torture_param(bool, gp_poll_exp_full, false, "Use polling full-state expedited GP wait primitives");
Paul E. McKenneyf0bf8fa2014-03-21 16:17:56 -070096torture_param(bool, gp_sync, false, "Use synchronous GP wait primitives");
Paul E. McKenney9e250222014-01-27 16:27:00 -080097torture_param(int, irqreader, 1, "Allow RCU readers from irq handlers");
Paul E. McKenneyd6855142020-08-11 10:33:39 -070098torture_param(int, leakpointer, 0, "Leak pointer dereferences from readers");
Paul E. McKenneycb506e12022-04-17 20:43:13 -070099torture_param(int, n_barrier_cbs, 0, "# of callbacks/kthreads for barrier testing");
Paul E. McKenney9e250222014-01-27 16:27:00 -0800100torture_param(int, nfakewriters, 4, "Number of RCU fake writer threads");
101torture_param(int, nreaders, -1, "Number of RCU reader threads");
Paul E. McKenneycb506e12022-04-17 20:43:13 -0700102torture_param(int, object_debug, 0, "Enable debug-object double call_rcu() testing");
Paul E. McKenney9e250222014-01-27 16:27:00 -0800103torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)");
Paul E. McKenneycb506e12022-04-17 20:43:13 -0700104torture_param(int, onoff_interval, 0, "Time between CPU hotplugs (jiffies), 0=disable");
Paul E. McKenney2c4319b2020-09-23 17:39:46 -0700105torture_param(int, nocbs_nthreads, 0, "Number of NOCB toggle threads, 0 to disable");
106torture_param(int, nocbs_toggle, 1000, "Time between toggling nocb state (ms)");
Paul E. McKenneycb506e12022-04-17 20:43:13 -0700107torture_param(int, read_exit_delay, 13, "Delay between read-then-exit episodes (s)");
108torture_param(int, read_exit_burst, 16, "# of read-then-exit bursts per episode, zero to disable");
Paul E. McKenney9e250222014-01-27 16:27:00 -0800109torture_param(int, shuffle_interval, 3, "Number of seconds between shuffles");
110torture_param(int, shutdown_secs, 0, "Shutdown time (s), <= zero to disable.");
111torture_param(int, stall_cpu, 0, "Stall duration (s), zero to disable.");
Paul E. McKenneycb506e12022-04-17 20:43:13 -0700112torture_param(int, stall_cpu_holdoff, 10, "Time to wait before starting stall (s).");
113torture_param(bool, stall_no_softlockup, false, "Avoid softlockup warning during cpu stall.");
Paul E. McKenney2b1516e2017-08-18 16:11:37 -0700114torture_param(int, stall_cpu_irqsoff, 0, "Disable interrupts while stalling.");
Paul E. McKenney19a8ff92020-03-11 17:39:12 -0700115torture_param(int, stall_cpu_block, 0, "Sleep while stalling.");
Paul E. McKenneycb506e12022-04-17 20:43:13 -0700116torture_param(int, stall_gp_kthread, 0, "Grace-period kthread stall duration (s).");
117torture_param(int, stat_interval, 60, "Number of seconds between stats printk()s");
Paul E. McKenney9e250222014-01-27 16:27:00 -0800118torture_param(int, stutter, 5, "Number of seconds to run/halt test");
119torture_param(int, test_boost, 1, "Test RCU prio boost: 0=no, 1=maybe, 2=yes.");
Paul E. McKenneycb506e12022-04-17 20:43:13 -0700120torture_param(int, test_boost_duration, 4, "Duration of each boost test, seconds.");
121torture_param(int, test_boost_interval, 7, "Interval between boost tests, seconds.");
122torture_param(bool, test_no_idle_hz, true, "Test support for tickless idle CPUs");
123torture_param(int, verbose, 1, "Enable verbose debugging printk()s");
Paul E. McKenney9e250222014-01-27 16:27:00 -0800124
Paul E. McKenneyb5daa8f2014-01-30 13:38:09 -0800125static char *torture_type = "rcu";
Josh Triplettd6ad6712007-03-06 01:42:13 -0800126module_param(torture_type, charp, 0444);
Paul E. McKenneyc770c822018-07-07 10:28:07 -0700127MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, srcu, ...)");
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700128
Paul E. McKenney2c4319b2020-09-23 17:39:46 -0700129static int nrealnocbers;
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800130static int nrealreaders;
131static struct task_struct *writer_task;
Josh Triplettb772e1d2006-10-04 02:17:13 -0700132static struct task_struct **fakewriter_tasks;
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800133static struct task_struct **reader_tasks;
Paul E. McKenney2c4319b2020-09-23 17:39:46 -0700134static struct task_struct **nocb_tasks;
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800135static struct task_struct *stats_task;
Paul E. McKenneybf66f182010-01-04 15:09:10 -0800136static struct task_struct *fqs_task;
Paul E. McKenney8e8be452010-09-02 16:16:14 -0700137static struct task_struct *boost_tasks[NR_CPUS];
Paul E. McKenneyc13f3752012-01-20 15:36:33 -0800138static struct task_struct *stall_task;
Paul E. McKenney82e31002021-11-22 20:55:18 -0800139static struct task_struct **fwd_prog_tasks;
Paul E. McKenneyfae4b542012-02-20 17:51:45 -0800140static struct task_struct **barrier_cbs_tasks;
141static struct task_struct *barrier_task;
Paul E. McKenney4a5f1332020-04-24 11:21:40 -0700142static struct task_struct *read_exit_task;
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800143
144#define RCU_TORTURE_PIPE_LEN 10
145
Paul E. McKenney00504532020-10-29 15:08:57 -0700146// Mailbox-like structure to check RCU global memory ordering.
147struct rcu_torture_reader_check {
148 unsigned long rtc_myloops;
149 int rtc_chkrdr;
150 unsigned long rtc_chkloops;
151 int rtc_ready;
152 struct rcu_torture_reader_check *rtc_assigner;
153} ____cacheline_internodealigned_in_smp;
154
155// Update-side data structure used to check RCU readers.
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800156struct rcu_torture {
157 struct rcu_head rtort_rcu;
158 int rtort_pipe_count;
159 struct list_head rtort_free;
Paul E. McKenney996417d2005-11-18 01:10:50 -0800160 int rtort_mbtest;
Paul E. McKenney00504532020-10-29 15:08:57 -0700161 struct rcu_torture_reader_check *rtort_chkp;
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800162};
163
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800164static LIST_HEAD(rcu_torture_freelist);
Paul E. McKenney0ddea0e2010-09-19 21:06:14 -0700165static struct rcu_torture __rcu *rcu_torture_current;
Paul E. McKenney4a298652011-04-03 21:33:51 -0700166static unsigned long rcu_torture_current_version;
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800167static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN];
168static DEFINE_SPINLOCK(rcu_torture_lock);
Paul E. McKenney67522be2016-03-01 08:52:19 -0800169static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count);
170static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800171static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1];
Paul E. McKenney00504532020-10-29 15:08:57 -0700172static struct rcu_torture_reader_check *rcu_torture_reader_mbchk;
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700173static atomic_t n_rcu_torture_alloc;
174static atomic_t n_rcu_torture_alloc_fail;
175static atomic_t n_rcu_torture_free;
176static atomic_t n_rcu_torture_mberror;
Paul E. McKenney00504532020-10-29 15:08:57 -0700177static atomic_t n_rcu_torture_mbchk_fail;
178static atomic_t n_rcu_torture_mbchk_tries;
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700179static atomic_t n_rcu_torture_error;
Paul E. McKenneyfae4b542012-02-20 17:51:45 -0800180static long n_rcu_torture_barrier_error;
Paul E. McKenney8e8be452010-09-02 16:16:14 -0700181static long n_rcu_torture_boost_ktrerror;
182static long n_rcu_torture_boost_rterror;
Paul E. McKenney8e8be452010-09-02 16:16:14 -0700183static long n_rcu_torture_boost_failure;
184static long n_rcu_torture_boosts;
Paul E. McKenney8da9a592018-05-22 11:17:51 -0700185static atomic_long_t n_rcu_torture_timers;
Paul E. McKenneyfae4b542012-02-20 17:51:45 -0800186static long n_barrier_attempts;
Joel Fernandes (Google)bf5b6432018-06-19 15:14:19 -0700187static long n_barrier_successes; /* did rcu_barrier test succeed? */
Paul E. McKenney4a5f1332020-04-24 11:21:40 -0700188static unsigned long n_read_exits;
Josh Triplette3033732006-10-04 02:17:14 -0700189static struct list_head rcu_torture_removed;
Paul E. McKenney60013d52019-07-10 08:30:00 -0700190static unsigned long shutdown_jiffies;
Joel Fernandes (Google)959954d2020-06-18 16:29:55 -0400191static unsigned long start_gp_seq;
Paul E. McKenney2c4319b2020-09-23 17:39:46 -0700192static atomic_long_t n_nocb_offload;
193static atomic_long_t n_nocb_deoffload;
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800194
Paul E. McKenneyad0dc7f2014-02-19 10:51:42 -0800195static int rcu_torture_writer_state;
196#define RTWS_FIXED_DELAY 0
197#define RTWS_DELAY 1
198#define RTWS_REPLACE 2
199#define RTWS_DEF_FREE 3
200#define RTWS_EXP_SYNC 4
Paul E. McKenneya48f3fa2014-03-18 15:57:41 -0700201#define RTWS_COND_GET 5
Paul E. McKenneyb6fe4912022-08-04 13:46:05 -0700202#define RTWS_COND_GET_FULL 6
203#define RTWS_COND_GET_EXP 7
Paul E. McKenney8df13f02022-08-04 15:23:26 -0700204#define RTWS_COND_GET_EXP_FULL 8
205#define RTWS_COND_SYNC 9
206#define RTWS_COND_SYNC_FULL 10
207#define RTWS_COND_SYNC_EXP 11
208#define RTWS_COND_SYNC_EXP_FULL 12
209#define RTWS_POLL_GET 13
210#define RTWS_POLL_GET_FULL 14
211#define RTWS_POLL_GET_EXP 15
212#define RTWS_POLL_GET_EXP_FULL 16
213#define RTWS_POLL_WAIT 17
214#define RTWS_POLL_WAIT_FULL 18
215#define RTWS_POLL_WAIT_EXP 19
216#define RTWS_POLL_WAIT_EXP_FULL 20
217#define RTWS_SYNC 21
218#define RTWS_STUTTER 22
219#define RTWS_STOPPING 23
Paul E. McKenney18aff332015-11-17 13:35:28 -0800220static const char * const rcu_torture_writer_state_names[] = {
221 "RTWS_FIXED_DELAY",
222 "RTWS_DELAY",
223 "RTWS_REPLACE",
224 "RTWS_DEF_FREE",
225 "RTWS_EXP_SYNC",
226 "RTWS_COND_GET",
Paul E. McKenneyb6fe4912022-08-04 13:46:05 -0700227 "RTWS_COND_GET_FULL",
Paul E. McKenney11d62f02022-02-01 07:01:20 -0800228 "RTWS_COND_GET_EXP",
Paul E. McKenney8df13f02022-08-04 15:23:26 -0700229 "RTWS_COND_GET_EXP_FULL",
Paul E. McKenney18aff332015-11-17 13:35:28 -0800230 "RTWS_COND_SYNC",
Paul E. McKenneyb6fe4912022-08-04 13:46:05 -0700231 "RTWS_COND_SYNC_FULL",
Paul E. McKenney11d62f02022-02-01 07:01:20 -0800232 "RTWS_COND_SYNC_EXP",
Paul E. McKenney8df13f02022-08-04 15:23:26 -0700233 "RTWS_COND_SYNC_EXP_FULL",
Paul E. McKenney0fd05482020-11-13 20:43:59 -0800234 "RTWS_POLL_GET",
Paul E. McKenney76ea3642022-08-02 17:04:54 -0700235 "RTWS_POLL_GET_FULL",
Paul E. McKenney11d62f02022-02-01 07:01:20 -0800236 "RTWS_POLL_GET_EXP",
Paul E. McKenney6c502b12022-08-03 12:38:51 -0700237 "RTWS_POLL_GET_EXP_FULL",
Paul E. McKenney0fd05482020-11-13 20:43:59 -0800238 "RTWS_POLL_WAIT",
Paul E. McKenney76ea3642022-08-02 17:04:54 -0700239 "RTWS_POLL_WAIT_FULL",
Paul E. McKenney11d62f02022-02-01 07:01:20 -0800240 "RTWS_POLL_WAIT_EXP",
Paul E. McKenney6c502b12022-08-03 12:38:51 -0700241 "RTWS_POLL_WAIT_EXP_FULL",
Paul E. McKenney18aff332015-11-17 13:35:28 -0800242 "RTWS_SYNC",
243 "RTWS_STUTTER",
244 "RTWS_STOPPING",
245};
246
Paul E. McKenneyc116dba2018-07-13 12:09:14 -0700247/* Record reader segment types and duration for first failing read. */
248struct rt_read_seg {
249 int rt_readstate;
250 unsigned long rt_delay_jiffies;
251 unsigned long rt_delay_ms;
252 unsigned long rt_delay_us;
253 bool rt_preempted;
254};
255static int err_segs_recorded;
256static struct rt_read_seg err_segs[RCUTORTURE_RDR_MAX_SEGS];
257static int rt_read_nsegs;
258
Paul E. McKenney18aff332015-11-17 13:35:28 -0800259static const char *rcu_torture_writer_state_getname(void)
260{
261 unsigned int i = READ_ONCE(rcu_torture_writer_state);
262
263 if (i >= ARRAY_SIZE(rcu_torture_writer_state_names))
264 return "???";
265 return rcu_torture_writer_state_names[i];
266}
Paul E. McKenneyad0dc7f2014-02-19 10:51:42 -0800267
Steven Rostedte4aa0da2013-02-04 13:36:13 -0500268#ifdef CONFIG_RCU_TRACE
269static u64 notrace rcu_trace_clock_local(void)
270{
271 u64 ts = trace_clock_local();
Paul E. McKenneya3b7b6c2017-06-23 16:07:17 -0700272
273 (void)do_div(ts, NSEC_PER_USEC);
Steven Rostedte4aa0da2013-02-04 13:36:13 -0500274 return ts;
275}
276#else /* #ifdef CONFIG_RCU_TRACE */
277static u64 notrace rcu_trace_clock_local(void)
278{
279 return 0ULL;
280}
281#endif /* #else #ifdef CONFIG_RCU_TRACE */
282
Paul E. McKenney60013d52019-07-10 08:30:00 -0700283/*
284 * Stop aggressive CPU-hog tests a bit before the end of the test in order
285 * to avoid interfering with test shutdown.
286 */
287static bool shutdown_time_arrived(void)
288{
289 return shutdown_secs && time_after(jiffies, shutdown_jiffies - 30 * HZ);
290}
291
Paul E. McKenney8e8be452010-09-02 16:16:14 -0700292static unsigned long boost_starttime; /* jiffies of next boost test start. */
Pranith Kumar58ade2d2014-06-11 16:39:43 -0400293static DEFINE_MUTEX(boost_mutex); /* protect setting boost_starttime */
Paul E. McKenney8e8be452010-09-02 16:16:14 -0700294 /* and boost task create/destroy. */
Paul E. McKenneyfae4b542012-02-20 17:51:45 -0800295static atomic_t barrier_cbs_count; /* Barrier callbacks registered. */
Paul E. McKenneyc6ebcbb2012-05-28 19:21:41 -0700296static bool barrier_phase; /* Test phase. */
Paul E. McKenneyfae4b542012-02-20 17:51:45 -0800297static atomic_t barrier_cbs_invoked; /* Barrier callbacks invoked. */
298static wait_queue_head_t *barrier_cbs_wq; /* Coordinate barrier testing. */
299static DECLARE_WAIT_QUEUE_HEAD(barrier_wq);
Paul E. McKenney8e8be452010-09-02 16:16:14 -0700300
Paul E. McKenneye22ef8d2021-12-17 12:33:53 -0800301static atomic_t rcu_fwd_cb_nodelay; /* Short rcu_torture_delay() delays. */
Paul E. McKenney48718482018-08-15 15:32:51 -0700302
Paul E. McKenney343e9092008-12-15 16:13:07 -0800303/*
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800304 * Allocate an element from the rcu_tortures pool.
305 */
Adrian Bunk97a41e22006-01-08 01:02:17 -0800306static struct rcu_torture *
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800307rcu_torture_alloc(void)
308{
309 struct list_head *p;
310
Ingo Molnaradac1662006-01-25 19:50:12 +0100311 spin_lock_bh(&rcu_torture_lock);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800312 if (list_empty(&rcu_torture_freelist)) {
313 atomic_inc(&n_rcu_torture_alloc_fail);
Ingo Molnaradac1662006-01-25 19:50:12 +0100314 spin_unlock_bh(&rcu_torture_lock);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800315 return NULL;
316 }
317 atomic_inc(&n_rcu_torture_alloc);
318 p = rcu_torture_freelist.next;
319 list_del_init(p);
Ingo Molnaradac1662006-01-25 19:50:12 +0100320 spin_unlock_bh(&rcu_torture_lock);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800321 return container_of(p, struct rcu_torture, rtort_free);
322}
323
324/*
325 * Free an element to the rcu_tortures pool.
326 */
327static void
328rcu_torture_free(struct rcu_torture *p)
329{
330 atomic_inc(&n_rcu_torture_free);
Ingo Molnaradac1662006-01-25 19:50:12 +0100331 spin_lock_bh(&rcu_torture_lock);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800332 list_add_tail(&p->rtort_free, &rcu_torture_freelist);
Ingo Molnaradac1662006-01-25 19:50:12 +0100333 spin_unlock_bh(&rcu_torture_lock);
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800334}
335
Paul E. McKenneya241ec62005-10-30 15:03:12 -0800336/*
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700337 * Operations vector for selecting different types of tests.
338 */
339
340struct rcu_torture_ops {
Paul E. McKenneyad0dc7f2014-02-19 10:51:42 -0800341 int ttype;
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700342 void (*init)(void);
Paul E. McKenneyca1d51e2015-04-14 12:28:22 -0700343 void (*cleanup)(void);
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700344 int (*readlock)(void);
Paul E. McKenneyc116dba2018-07-13 12:09:14 -0700345 void (*read_delay)(struct torture_random_state *rrsp,
346 struct rt_read_seg *rtrsp);
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700347 void (*readunlock)(int idx);
Paul E. McKenneya5c095e2021-03-13 20:05:31 -0800348 int (*readlock_held)(void);
Paul E. McKenney17ef2fe2018-04-27 11:39:34 -0700349 unsigned long (*get_gp_seq)(void);
Paul E. McKenneyd72193122018-05-15 15:24:41 -0700350 unsigned long (*gp_diff)(unsigned long new, unsigned long old);
Paul E. McKenney0acc5122009-06-25 09:08:17 -0700351 void (*deferred_free)(struct rcu_torture *p);
Josh Triplettb772e1d2006-10-04 02:17:13 -0700352 void (*sync)(void);
Paul E. McKenney2ec1f2d92013-06-12 15:12:21 -0700353 void (*exp_sync)(void);
Paul E. McKenney11d62f02022-02-01 07:01:20 -0800354 unsigned long (*get_gp_state_exp)(void);
355 unsigned long (*start_gp_poll_exp)(void);
Paul E. McKenney6c502b12022-08-03 12:38:51 -0700356 void (*start_gp_poll_exp_full)(struct rcu_gp_oldstate *rgosp);
Paul E. McKenney11d62f02022-02-01 07:01:20 -0800357 bool (*poll_gp_state_exp)(unsigned long oldstate);
358 void (*cond_sync_exp)(unsigned long oldstate);
Paul E. McKenney8df13f02022-08-04 15:23:26 -0700359 void (*cond_sync_exp_full)(struct rcu_gp_oldstate *rgosp);
Paul E. McKenneyfd56f64b2020-11-13 20:14:27 -0800360 unsigned long (*get_gp_state)(void);
Paul E. McKenney3fdefca2022-07-28 19:58:13 -0700361 void (*get_gp_state_full)(struct rcu_gp_oldstate *rgosp);
Paul E. McKenneyd0eac202022-04-13 16:14:02 -0700362 unsigned long (*get_gp_completed)(void);
Paul E. McKenney91a967f2022-07-28 15:37:05 -0700363 void (*get_gp_completed_full)(struct rcu_gp_oldstate *rgosp);
Paul E. McKenney0fd05482020-11-13 20:43:59 -0800364 unsigned long (*start_gp_poll)(void);
Paul E. McKenney76ea3642022-08-02 17:04:54 -0700365 void (*start_gp_poll_full)(struct rcu_gp_oldstate *rgosp);
Paul E. McKenney0fd05482020-11-13 20:43:59 -0800366 bool (*poll_gp_state)(unsigned long oldstate);
Paul E. McKenney91a967f2022-07-28 15:37:05 -0700367 bool (*poll_gp_state_full)(struct rcu_gp_oldstate *rgosp);
Paul E. McKenneyed7d2f12022-08-01 16:57:17 -0700368 bool (*poll_need_2gp)(bool poll, bool poll_full);
Paul E. McKenneya48f3fa2014-03-18 15:57:41 -0700369 void (*cond_sync)(unsigned long oldstate);
Paul E. McKenneyb6fe4912022-08-04 13:46:05 -0700370 void (*cond_sync_full)(struct rcu_gp_oldstate *rgosp);
Boqun Fengdb3e8db2015-07-29 13:29:39 +0800371 call_rcu_func_t call;
Paul E. McKenney23269742008-05-12 21:21:05 +0200372 void (*cb_barrier)(void);
Paul E. McKenneybf66f182010-01-04 15:09:10 -0800373 void (*fqs)(void);
Joe Percheseea203f2014-07-14 09:16:15 -0400374 void (*stats)(void);
Paul E. McKenney27c0f142020-09-15 17:08:03 -0700375 void (*gp_kthread_dbg)(void);
Paul E. McKenney0260b922021-04-08 13:01:14 -0700376 bool (*check_boost_failed)(unsigned long gp_state, int *cpup);
Paul E. McKenney1b272912018-07-18 14:32:31 -0700377 int (*stall_dur)(void);
Paul E. McKenney613b00f2021-11-23 11:53:52 -0800378 long cbflood_max;
Paul E. McKenney0acc5122009-06-25 09:08:17 -0700379 int irq_capable;
Paul E. McKenney8e8be452010-09-02 16:16:14 -0700380 int can_boost;
Paul E. McKenney2397d072018-05-25 07:29:25 -0700381 int extendables;
Paul E. McKenney5eabea52019-04-12 09:02:46 -0700382 int slow_gps;
Paul E. McKenney340170f2021-09-24 21:30:26 -0700383 int no_pi_lock;
Steven Rostedt (Red Hat)e66c33d2013-07-12 16:50:28 -0400384 const char *name;
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700385};
Paul E. McKenneya71fca52009-09-18 10:28:19 -0700386
387static struct rcu_torture_ops *cur_ops;
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700388
389/*
390 * Definitions for rcu torture testing.
391 */
392
Paul E. McKenneya5c095e2021-03-13 20:05:31 -0800393static int torture_readlock_not_held(void)
394{
395 return rcu_read_lock_bh_held() || rcu_read_lock_sched_held();
396}
397
Josh Tripletta49a4af2006-09-29 01:59:30 -0700398static int rcu_torture_read_lock(void) __acquires(RCU)
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700399{
400 rcu_read_lock();
401 return 0;
402}
403
Paul E. McKenneyc116dba2018-07-13 12:09:14 -0700404static void
405rcu_read_delay(struct torture_random_state *rrsp, struct rt_read_seg *rtrsp)
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700406{
Paul E. McKenneyd0af39e2016-10-10 18:26:04 -0700407 unsigned long started;
408 unsigned long completed;
Josh Triplettb8d57a72009-09-08 15:54:35 -0700409 const unsigned long shortdelay_us = 200;
Paul E. McKenney1e696762018-07-20 12:04:12 -0700410 unsigned long longdelay_ms = 300;
Paul E. McKenneyd0af39e2016-10-10 18:26:04 -0700411 unsigned long long ts;
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700412
Josh Triplettb8d57a72009-09-08 15:54:35 -0700413 /* We want a short delay sometimes to make a reader delay the grace
414 * period, and we want a long delay occasionally to trigger
415 * force_quiescent_state. */
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700416
Paul E. McKenneye22ef8d2021-12-17 12:33:53 -0800417 if (!atomic_read(&rcu_fwd_cb_nodelay) &&
Paul E. McKenney48718482018-08-15 15:32:51 -0700418 !(torture_random(rrsp) % (nrealreaders * 2000 * longdelay_ms))) {
Paul E. McKenney17ef2fe2018-04-27 11:39:34 -0700419 started = cur_ops->get_gp_seq();
Paul E. McKenneyd0af39e2016-10-10 18:26:04 -0700420 ts = rcu_trace_clock_local();
Paul E. McKenney1e696762018-07-20 12:04:12 -0700421 if (preempt_count() & (SOFTIRQ_MASK | HARDIRQ_MASK))
422 longdelay_ms = 5; /* Avoid triggering BH limits. */
Josh Triplettb8d57a72009-09-08 15:54:35 -0700423 mdelay(longdelay_ms);
Paul E. McKenneyc116dba2018-07-13 12:09:14 -0700424 rtrsp->rt_delay_ms = longdelay_ms;
Paul E. McKenney17ef2fe2018-04-27 11:39:34 -0700425 completed = cur_ops->get_gp_seq();
Paul E. McKenneyd0af39e2016-10-10 18:26:04 -0700426 do_trace_rcu_torture_read(cur_ops->name, NULL, ts,
427 started, completed);
428 }
Paul E. McKenneyc116dba2018-07-13 12:09:14 -0700429 if (!(torture_random(rrsp) % (nrealreaders * 2 * shortdelay_us))) {
Josh Triplettb8d57a72009-09-08 15:54:35 -0700430 udelay(shortdelay_us);
Paul E. McKenneyc116dba2018-07-13 12:09:14 -0700431 rtrsp->rt_delay_us = shortdelay_us;
432 }
Paul E. McKenney51b11302014-01-27 11:49:39 -0800433 if (!preempt_count() &&
Paul E. McKenneyc116dba2018-07-13 12:09:14 -0700434 !(torture_random(rrsp) % (nrealreaders * 500))) {
Paul E. McKenneycc1321c2017-10-16 11:05:03 -0700435 torture_preempt_schedule(); /* QS only if preemptible. */
Paul E. McKenneyc116dba2018-07-13 12:09:14 -0700436 rtrsp->rt_preempted = true;
437 }
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700438}
439
Josh Tripletta49a4af2006-09-29 01:59:30 -0700440static void rcu_torture_read_unlock(int idx) __releases(RCU)
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700441{
442 rcu_read_unlock();
443}
444
Paul E. McKenneya48f3fa2014-03-18 15:57:41 -0700445/*
446 * Update callback in the pipe. This should be invoked after a grace period.
447 */
448static bool
449rcu_torture_pipe_update_one(struct rcu_torture *rp)
450{
451 int i;
Paul E. McKenney00504532020-10-29 15:08:57 -0700452 struct rcu_torture_reader_check *rtrcp = READ_ONCE(rp->rtort_chkp);
Paul E. McKenneya48f3fa2014-03-18 15:57:41 -0700453
Paul E. McKenney00504532020-10-29 15:08:57 -0700454 if (rtrcp) {
455 WRITE_ONCE(rp->rtort_chkp, NULL);
456 smp_store_release(&rtrcp->rtc_ready, 1); // Pair with smp_load_acquire().
457 }
Paul E. McKenney20248912019-12-21 10:41:48 -0800458 i = READ_ONCE(rp->rtort_pipe_count);
Paul E. McKenneya48f3fa2014-03-18 15:57:41 -0700459 if (i > RCU_TORTURE_PIPE_LEN)
460 i = RCU_TORTURE_PIPE_LEN;
461 atomic_inc(&rcu_torture_wcount[i]);
Paul E. McKenney20248912019-12-21 10:41:48 -0800462 WRITE_ONCE(rp->rtort_pipe_count, i + 1);
463 if (rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) {
Paul E. McKenneya48f3fa2014-03-18 15:57:41 -0700464 rp->rtort_mbtest = 0;
465 return true;
466 }
467 return false;
468}
469
470/*
471 * Update all callbacks in the pipe. Suitable for synchronous grace-period
472 * primitives.
473 */
474static void
475rcu_torture_pipe_update(struct rcu_torture *old_rp)
476{
477 struct rcu_torture *rp;
478 struct rcu_torture *rp1;
479
480 if (old_rp)
481 list_add(&old_rp->rtort_free, &rcu_torture_removed);
482 list_for_each_entry_safe(rp, rp1, &rcu_torture_removed, rtort_free) {
483 if (rcu_torture_pipe_update_one(rp)) {
484 list_del(&rp->rtort_free);
485 rcu_torture_free(rp);
486 }
487 }
488}
489
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700490static void
491rcu_torture_cb(struct rcu_head *p)
492{
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700493 struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu);
494
Paul E. McKenney36970bb2014-01-30 15:49:29 -0800495 if (torture_must_stop_irq()) {
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700496 /* Test is ending, just drop callbacks on the floor. */
497 /* The next initialization will pick up the pieces. */
498 return;
499 }
Paul E. McKenneya48f3fa2014-03-18 15:57:41 -0700500 if (rcu_torture_pipe_update_one(rp))
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700501 rcu_torture_free(rp);
Paul E. McKenneya48f3fa2014-03-18 15:57:41 -0700502 else
Paul E. McKenney0acc5122009-06-25 09:08:17 -0700503 cur_ops->deferred_free(rp);
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700504}
505
Paul E. McKenney6b80da42014-11-21 14:19:26 -0800506static unsigned long rcu_no_completed(void)
Paul E. McKenneyd9a3da02009-12-02 12:10:15 -0800507{
508 return 0;
509}
510
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700511static void rcu_torture_deferred_free(struct rcu_torture *p)
512{
513 call_rcu(&p->rtort_rcu, rcu_torture_cb);
514}
515
Paul E. McKenney2ec1f2d92013-06-12 15:12:21 -0700516static void rcu_sync_torture_init(void)
517{
518 INIT_LIST_HEAD(&rcu_torture_removed);
519}
520
Paul E. McKenneyed7d2f12022-08-01 16:57:17 -0700521static bool rcu_poll_need_2gp(bool poll, bool poll_full)
522{
Paul E. McKenneyb3cdd0a2022-08-04 18:05:46 -0700523 return poll;
Paul E. McKenneyed7d2f12022-08-01 16:57:17 -0700524}
525
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700526static struct rcu_torture_ops rcu_ops = {
Paul E. McKenney0260b922021-04-08 13:01:14 -0700527 .ttype = RCU_FLAVOR,
528 .init = rcu_sync_torture_init,
529 .readlock = rcu_torture_read_lock,
530 .read_delay = rcu_read_delay,
531 .readunlock = rcu_torture_read_unlock,
532 .readlock_held = torture_readlock_not_held,
533 .get_gp_seq = rcu_get_gp_seq,
534 .gp_diff = rcu_seq_diff,
535 .deferred_free = rcu_torture_deferred_free,
536 .sync = synchronize_rcu,
537 .exp_sync = synchronize_rcu_expedited,
538 .get_gp_state = get_state_synchronize_rcu,
Paul E. McKenney3fdefca2022-07-28 19:58:13 -0700539 .get_gp_state_full = get_state_synchronize_rcu_full,
Paul E. McKenneyd0eac202022-04-13 16:14:02 -0700540 .get_gp_completed = get_completed_synchronize_rcu,
Paul E. McKenney91a967f2022-07-28 15:37:05 -0700541 .get_gp_completed_full = get_completed_synchronize_rcu_full,
Paul E. McKenney0260b922021-04-08 13:01:14 -0700542 .start_gp_poll = start_poll_synchronize_rcu,
Paul E. McKenney76ea3642022-08-02 17:04:54 -0700543 .start_gp_poll_full = start_poll_synchronize_rcu_full,
Paul E. McKenney0260b922021-04-08 13:01:14 -0700544 .poll_gp_state = poll_state_synchronize_rcu,
Paul E. McKenney91a967f2022-07-28 15:37:05 -0700545 .poll_gp_state_full = poll_state_synchronize_rcu_full,
Paul E. McKenneyed7d2f12022-08-01 16:57:17 -0700546 .poll_need_2gp = rcu_poll_need_2gp,
Paul E. McKenney0260b922021-04-08 13:01:14 -0700547 .cond_sync = cond_synchronize_rcu,
Paul E. McKenneyb6fe4912022-08-04 13:46:05 -0700548 .cond_sync_full = cond_synchronize_rcu_full,
Paul E. McKenney11d62f02022-02-01 07:01:20 -0800549 .get_gp_state_exp = get_state_synchronize_rcu,
550 .start_gp_poll_exp = start_poll_synchronize_rcu_expedited,
Paul E. McKenney6c502b12022-08-03 12:38:51 -0700551 .start_gp_poll_exp_full = start_poll_synchronize_rcu_expedited_full,
Paul E. McKenney11d62f02022-02-01 07:01:20 -0800552 .poll_gp_state_exp = poll_state_synchronize_rcu,
553 .cond_sync_exp = cond_synchronize_rcu_expedited,
Paul E. McKenney0260b922021-04-08 13:01:14 -0700554 .call = call_rcu,
555 .cb_barrier = rcu_barrier,
556 .fqs = rcu_force_quiescent_state,
557 .stats = NULL,
558 .gp_kthread_dbg = show_rcu_gp_kthreads,
559 .check_boost_failed = rcu_check_boost_fail,
560 .stall_dur = rcu_jiffies_till_stall_check,
561 .irq_capable = 1,
562 .can_boost = IS_ENABLED(CONFIG_RCU_BOOST),
563 .extendables = RCUTORTURE_MAX_EXTEND,
564 .name = "rcu"
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700565};
566
Paul E. McKenneyc32e0662006-06-27 02:54:04 -0700567/*
Paul E. McKenneyff20e252014-02-06 08:45:56 -0800568 * Don't even think about trying any of these in real life!!!
569 * The names includes "busted", and they really means it!
570 * The only purpose of these functions is to provide a buggy RCU
571 * implementation to make sure that rcutorture correctly emits
572 * buggy-RCU error messages.
573 */
574static void rcu_busted_torture_deferred_free(struct rcu_torture *p)
575{
576 /* This is a deliberate bug for testing purposes only! */
577 rcu_torture_cb(&p->rtort_rcu);
578}
579
580static void synchronize_rcu_busted(void)
581{
582 /* This is a deliberate bug for testing purposes only! */
583}
584
585static void
Boqun Fengb6a4ae72015-07-29 13:29:38 +0800586call_rcu_busted(struct rcu_head *head, rcu_callback_t func)
Paul E. McKenneyff20e252014-02-06 08:45:56 -0800587{
588 /* This is a deliberate bug for testing purposes only! */
589 func(head);
590}
591
592static struct rcu_torture_ops rcu_busted_ops = {
Paul E. McKenneyad0dc7f2014-02-19 10:51:42 -0800593 .ttype = INVALID_RCU_FLAVOR,
Paul E. McKenneyff20e252014-02-06 08:45:56 -0800594 .init = rcu_sync_torture_init,
595 .readlock = rcu_torture_read_lock,
596 .read_delay = rcu_read_delay, /* just reuse rcu's version. */
597 .readunlock = rcu_torture_read_unlock,
Paul E. McKenneya5c095e2021-03-13 20:05:31 -0800598 .readlock_held = torture_readlock_not_held,
Paul E. McKenney17ef2fe2018-04-27 11:39:34 -0700599 .get_gp_seq = rcu_no_completed,
Paul E. McKenneyff20e252014-02-06 08:45:56 -0800600 .deferred_free = rcu_busted_torture_deferred_free,
601 .sync = synchronize_rcu_busted,
602 .exp_sync = synchronize_rcu_busted,
603 .call = call_rcu_busted,
604 .cb_barrier = NULL,
605 .fqs = NULL,
606 .stats = NULL,
607 .irq_capable = 1,
Paul E. McKenneyb3c98312017-06-06 16:39:00 -0700608 .name = "busted"
Paul E. McKenneyff20e252014-02-06 08:45:56 -0800609};
610
611/*
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700612 * Definitions for srcu torture testing.
613 */
614
Lai Jiangshancda4dc82012-10-13 01:14:17 +0800615DEFINE_STATIC_SRCU(srcu_ctl);
Paul E. McKenneyca1d51e2015-04-14 12:28:22 -0700616static struct srcu_struct srcu_ctld;
617static struct srcu_struct *srcu_ctlp = &srcu_ctl;
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700618
Paul E. McKenneyca1d51e2015-04-14 12:28:22 -0700619static int srcu_torture_read_lock(void) __acquires(srcu_ctlp)
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700620{
Paul E. McKenneyca1d51e2015-04-14 12:28:22 -0700621 return srcu_read_lock(srcu_ctlp);
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700622}
623
Paul E. McKenneyc116dba2018-07-13 12:09:14 -0700624static void
625srcu_read_delay(struct torture_random_state *rrsp, struct rt_read_seg *rtrsp)
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700626{
627 long delay;
628 const long uspertick = 1000000 / HZ;
629 const long longdelay = 10;
630
631 /* We want there to be long-running readers, but not all the time. */
632
Paul E. McKenney51b11302014-01-27 11:49:39 -0800633 delay = torture_random(rrsp) %
634 (nrealreaders * 2 * longdelay * uspertick);
Paul E. McKenneyc116dba2018-07-13 12:09:14 -0700635 if (!delay && in_task()) {
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700636 schedule_timeout_interruptible(longdelay);
Paul E. McKenneyc116dba2018-07-13 12:09:14 -0700637 rtrsp->rt_delay_jiffies = longdelay;
638 } else {
639 rcu_read_delay(rrsp, rtrsp);
640 }
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700641}
642
Paul E. McKenneyca1d51e2015-04-14 12:28:22 -0700643static void srcu_torture_read_unlock(int idx) __releases(srcu_ctlp)
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700644{
Paul E. McKenneyca1d51e2015-04-14 12:28:22 -0700645 srcu_read_unlock(srcu_ctlp, idx);
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700646}
647
Paul E. McKenneya5c095e2021-03-13 20:05:31 -0800648static int torture_srcu_read_lock_held(void)
649{
650 return srcu_read_lock_held(srcu_ctlp);
651}
652
Paul E. McKenney6b80da42014-11-21 14:19:26 -0800653static unsigned long srcu_torture_completed(void)
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700654{
Paul E. McKenneyca1d51e2015-04-14 12:28:22 -0700655 return srcu_batches_completed(srcu_ctlp);
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700656}
657
Lai Jiangshan9059c942012-03-19 16:12:14 +0800658static void srcu_torture_deferred_free(struct rcu_torture *rp)
659{
Paul E. McKenneyca1d51e2015-04-14 12:28:22 -0700660 call_srcu(srcu_ctlp, &rp->rtort_rcu, rcu_torture_cb);
Lai Jiangshan9059c942012-03-19 16:12:14 +0800661}
662
Josh Triplettb772e1d2006-10-04 02:17:13 -0700663static void srcu_torture_synchronize(void)
664{
Paul E. McKenneyca1d51e2015-04-14 12:28:22 -0700665 synchronize_srcu(srcu_ctlp);
Josh Triplettb772e1d2006-10-04 02:17:13 -0700666}
667
Paul E. McKenney0fd05482020-11-13 20:43:59 -0800668static unsigned long srcu_torture_get_gp_state(void)
669{
670 return get_state_synchronize_srcu(srcu_ctlp);
671}
672
673static unsigned long srcu_torture_start_gp_poll(void)
674{
675 return start_poll_synchronize_srcu(srcu_ctlp);
676}
677
678static bool srcu_torture_poll_gp_state(unsigned long oldstate)
679{
680 return poll_state_synchronize_srcu(srcu_ctlp, oldstate);
681}
682
Paul E. McKenneye3f8d372012-05-08 10:21:50 -0700683static void srcu_torture_call(struct rcu_head *head,
Boqun Fengb6a4ae72015-07-29 13:29:38 +0800684 rcu_callback_t func)
Paul E. McKenneye3f8d372012-05-08 10:21:50 -0700685{
Paul E. McKenneyca1d51e2015-04-14 12:28:22 -0700686 call_srcu(srcu_ctlp, head, func);
Paul E. McKenneye3f8d372012-05-08 10:21:50 -0700687}
688
689static void srcu_torture_barrier(void)
690{
Paul E. McKenneyca1d51e2015-04-14 12:28:22 -0700691 srcu_barrier(srcu_ctlp);
Paul E. McKenneye3f8d372012-05-08 10:21:50 -0700692}
693
Joe Percheseea203f2014-07-14 09:16:15 -0400694static void srcu_torture_stats(void)
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700695{
Paul E. McKenney115a1a52017-05-22 13:31:03 -0700696 srcu_torture_stats_print(srcu_ctlp, torture_type, TORTURE_FLAG);
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700697}
698
Paul E. McKenney2ec1f2d92013-06-12 15:12:21 -0700699static void srcu_torture_synchronize_expedited(void)
700{
Paul E. McKenneyca1d51e2015-04-14 12:28:22 -0700701 synchronize_srcu_expedited(srcu_ctlp);
Paul E. McKenney2ec1f2d92013-06-12 15:12:21 -0700702}
703
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700704static struct rcu_torture_ops srcu_ops = {
Paul E. McKenneyad0dc7f2014-02-19 10:51:42 -0800705 .ttype = SRCU_FLAVOR,
Lai Jiangshancda4dc82012-10-13 01:14:17 +0800706 .init = rcu_sync_torture_init,
Paul E. McKenney0acc5122009-06-25 09:08:17 -0700707 .readlock = srcu_torture_read_lock,
708 .read_delay = srcu_read_delay,
709 .readunlock = srcu_torture_read_unlock,
Paul E. McKenneya5c095e2021-03-13 20:05:31 -0800710 .readlock_held = torture_srcu_read_lock_held,
Paul E. McKenney17ef2fe2018-04-27 11:39:34 -0700711 .get_gp_seq = srcu_torture_completed,
Lai Jiangshan9059c942012-03-19 16:12:14 +0800712 .deferred_free = srcu_torture_deferred_free,
Paul E. McKenney0acc5122009-06-25 09:08:17 -0700713 .sync = srcu_torture_synchronize,
Paul E. McKenney2ec1f2d92013-06-12 15:12:21 -0700714 .exp_sync = srcu_torture_synchronize_expedited,
Paul E. McKenney0fd05482020-11-13 20:43:59 -0800715 .get_gp_state = srcu_torture_get_gp_state,
716 .start_gp_poll = srcu_torture_start_gp_poll,
717 .poll_gp_state = srcu_torture_poll_gp_state,
Paul E. McKenneye3f8d372012-05-08 10:21:50 -0700718 .call = srcu_torture_call,
719 .cb_barrier = srcu_torture_barrier,
Paul E. McKenney0acc5122009-06-25 09:08:17 -0700720 .stats = srcu_torture_stats,
Paul E. McKenney9c0f1c72022-01-27 20:29:10 -0800721 .cbflood_max = 50000,
Paul E. McKenney5e741fa2017-06-06 12:52:44 -0700722 .irq_capable = 1,
Paul E. McKenney340170f2021-09-24 21:30:26 -0700723 .no_pi_lock = IS_ENABLED(CONFIG_TINY_SRCU),
Paul E. McKenney0acc5122009-06-25 09:08:17 -0700724 .name = "srcu"
Paul E. McKenneyb2896d22006-10-04 02:17:03 -0700725};
726
Paul E. McKenneyca1d51e2015-04-14 12:28:22 -0700727static void srcu_torture_init(void)
728{
729 rcu_sync_torture_init();
730 WARN_ON(init_srcu_struct(&srcu_ctld));
731 srcu_ctlp = &srcu_ctld;
732}
733
734static void srcu_torture_cleanup(void)
735{
Paul E. McKenneyf5ad3992019-02-13 13:54:37 -0800736 cleanup_srcu_struct(&srcu_ctld);
Paul E. McKenneyca1d51e2015-04-14 12:28:22 -0700737 srcu_ctlp = &srcu_ctl; /* In case of a later rcutorture run. */
738}
739
740/* As above, but dynamically allocated. */
741static struct rcu_torture_ops srcud_ops = {
742 .ttype = SRCU_FLAVOR,
743 .init = srcu_torture_init,
744 .cleanup = srcu_torture_cleanup,
745 .readlock = srcu_torture_read_lock,
746 .read_delay = srcu_read_delay,
747 .readunlock = srcu_torture_read_unlock,
Paul E. McKenneya5c095e2021-03-13 20:05:31 -0800748 .readlock_held = torture_srcu_read_lock_held,
Paul E. McKenney17ef2fe2018-04-27 11:39:34 -0700749 .get_gp_seq = srcu_torture_completed,
Paul E. McKenneyca1d51e2015-04-14 12:28:22 -0700750 .deferred_free = srcu_torture_deferred_free,
751 .sync = srcu_torture_synchronize,
752 .exp_sync = srcu_torture_synchronize_expedited,
Paul E. McKenney599d97e2022-07-27 16:16:41 -0700753 .get_gp_state = srcu_torture_get_gp_state,
754 .start_gp_poll = srcu_torture_start_gp_poll,
755 .poll_gp_state = srcu_torture_poll_gp_state,
Paul E. McKenneyca1d51e2015-04-14 12:28:22 -0700756 .call = srcu_torture_call,
757 .cb_barrier = srcu_torture_barrier,
758 .stats = srcu_torture_stats,
Paul E. McKenney9c0f1c72022-01-27 20:29:10 -0800759 .cbflood_max = 50000,
Paul E. McKenney5e741fa2017-06-06 12:52:44 -0700760 .irq_capable = 1,
Paul E. McKenney340170f2021-09-24 21:30:26 -0700761 .no_pi_lock = IS_ENABLED(CONFIG_TINY_SRCU),
Paul E. McKenneyca1d51e2015-04-14 12:28:22 -0700762 .name = "srcud"
763};
764
Paul E. McKenney2397d072018-05-25 07:29:25 -0700765/* As above, but broken due to inappropriate reader extension. */
766static struct rcu_torture_ops busted_srcud_ops = {
767 .ttype = SRCU_FLAVOR,
768 .init = srcu_torture_init,
769 .cleanup = srcu_torture_cleanup,
770 .readlock = srcu_torture_read_lock,
771 .read_delay = rcu_read_delay,
772 .readunlock = srcu_torture_read_unlock,
Paul E. McKenneya5c095e2021-03-13 20:05:31 -0800773 .readlock_held = torture_srcu_read_lock_held,
Paul E. McKenney2397d072018-05-25 07:29:25 -0700774 .get_gp_seq = srcu_torture_completed,
775 .deferred_free = srcu_torture_deferred_free,
776 .sync = srcu_torture_synchronize,
777 .exp_sync = srcu_torture_synchronize_expedited,
778 .call = srcu_torture_call,
779 .cb_barrier = srcu_torture_barrier,
780 .stats = srcu_torture_stats,
781 .irq_capable = 1,
Paul E. McKenney340170f2021-09-24 21:30:26 -0700782 .no_pi_lock = IS_ENABLED(CONFIG_TINY_SRCU),
Paul E. McKenney2397d072018-05-25 07:29:25 -0700783 .extendables = RCUTORTURE_MAX_EXTEND,
784 .name = "busted_srcud"
785};
786
Josh Triplett4b6c2cc2006-10-04 02:17:16 -0700787/*
Paul E. McKenney40c12782022-03-17 13:29:59 -0700788 * Definitions for trivial CONFIG_PREEMPT=n-only torture testing.
789 * This implementation does not necessarily work well with CPU hotplug.
790 */
791
792static void synchronize_rcu_trivial(void)
793{
794 int cpu;
795
796 for_each_online_cpu(cpu) {
797 rcutorture_sched_setaffinity(current->pid, cpumask_of(cpu));
798 WARN_ON_ONCE(raw_smp_processor_id() != cpu);
799 }
800}
801
802static int rcu_torture_read_lock_trivial(void) __acquires(RCU)
803{
804 preempt_disable();
805 return 0;
806}
807
808static void rcu_torture_read_unlock_trivial(int idx) __releases(RCU)
809{
810 preempt_enable();
811}
812
813static struct rcu_torture_ops trivial_ops = {
814 .ttype = RCU_TRIVIAL_FLAVOR,
815 .init = rcu_sync_torture_init,
816 .readlock = rcu_torture_read_lock_trivial,
817 .read_delay = rcu_read_delay, /* just reuse rcu's version. */
818 .readunlock = rcu_torture_read_unlock_trivial,
819 .readlock_held = torture_readlock_not_held,
820 .get_gp_seq = rcu_no_completed,
821 .sync = synchronize_rcu_trivial,
822 .exp_sync = synchronize_rcu_trivial,
823 .fqs = NULL,
824 .stats = NULL,
825 .irq_capable = 1,
826 .name = "trivial"
827};
828
Paul E. McKenney3b6e1dd2022-03-17 15:18:27 -0700829#ifdef CONFIG_TASKS_RCU
830
Paul E. McKenney40c12782022-03-17 13:29:59 -0700831/*
Paul E. McKenney69c60452014-07-01 11:59:36 -0700832 * Definitions for RCU-tasks torture testing.
833 */
834
835static int tasks_torture_read_lock(void)
836{
837 return 0;
838}
839
840static void tasks_torture_read_unlock(int idx)
841{
842}
843
844static void rcu_tasks_torture_deferred_free(struct rcu_torture *p)
845{
846 call_rcu_tasks(&p->rtort_rcu, rcu_torture_cb);
847}
848
Paul E. McKenney9cf8fc62020-03-06 14:00:46 -0800849static void synchronize_rcu_mult_test(void)
850{
851 synchronize_rcu_mult(call_rcu_tasks, call_rcu);
852}
853
Paul E. McKenney69c60452014-07-01 11:59:36 -0700854static struct rcu_torture_ops tasks_ops = {
855 .ttype = RCU_TASKS_FLAVOR,
856 .init = rcu_sync_torture_init,
857 .readlock = tasks_torture_read_lock,
858 .read_delay = rcu_read_delay, /* just reuse rcu's version. */
859 .readunlock = tasks_torture_read_unlock,
Paul E. McKenney17ef2fe2018-04-27 11:39:34 -0700860 .get_gp_seq = rcu_no_completed,
Paul E. McKenney69c60452014-07-01 11:59:36 -0700861 .deferred_free = rcu_tasks_torture_deferred_free,
862 .sync = synchronize_rcu_tasks,
Paul E. McKenney9cf8fc62020-03-06 14:00:46 -0800863 .exp_sync = synchronize_rcu_mult_test,
Paul E. McKenney69c60452014-07-01 11:59:36 -0700864 .call = call_rcu_tasks,
865 .cb_barrier = rcu_barrier_tasks,
Paul E. McKenney27c0f142020-09-15 17:08:03 -0700866 .gp_kthread_dbg = show_rcu_tasks_classic_gp_kthread,
Paul E. McKenney69c60452014-07-01 11:59:36 -0700867 .fqs = NULL,
868 .stats = NULL,
869 .irq_capable = 1,
Paul E. McKenney5eabea52019-04-12 09:02:46 -0700870 .slow_gps = 1,
Paul E. McKenney69c60452014-07-01 11:59:36 -0700871 .name = "tasks"
872};
873
Paul E. McKenney3b6e1dd2022-03-17 15:18:27 -0700874#define TASKS_OPS &tasks_ops,
Paul E. McKenneyc682db52019-04-19 07:38:27 -0700875
Paul E. McKenney3b6e1dd2022-03-17 15:18:27 -0700876#else // #ifdef CONFIG_TASKS_RCU
Paul E. McKenneyc682db52019-04-19 07:38:27 -0700877
Paul E. McKenney3b6e1dd2022-03-17 15:18:27 -0700878#define TASKS_OPS
Paul E. McKenneyc682db52019-04-19 07:38:27 -0700879
Paul E. McKenney3b6e1dd2022-03-17 15:18:27 -0700880#endif // #else #ifdef CONFIG_TASKS_RCU
Paul E. McKenneyc682db52019-04-19 07:38:27 -0700881
Paul E. McKenneyc682db52019-04-19 07:38:27 -0700882
Paul E. McKenney4c3f7b02022-03-17 16:16:45 -0700883#ifdef CONFIG_TASKS_RUDE_RCU
Paul E. McKenneyc682db52019-04-19 07:38:27 -0700884
Paul E. McKenney3d6e43c2020-03-03 15:02:50 -0800885/*
886 * Definitions for rude RCU-tasks torture testing.
887 */
888
889static void rcu_tasks_rude_torture_deferred_free(struct rcu_torture *p)
890{
891 call_rcu_tasks_rude(&p->rtort_rcu, rcu_torture_cb);
892}
893
894static struct rcu_torture_ops tasks_rude_ops = {
895 .ttype = RCU_TASKS_RUDE_FLAVOR,
896 .init = rcu_sync_torture_init,
897 .readlock = rcu_torture_read_lock_trivial,
898 .read_delay = rcu_read_delay, /* just reuse rcu's version. */
899 .readunlock = rcu_torture_read_unlock_trivial,
900 .get_gp_seq = rcu_no_completed,
901 .deferred_free = rcu_tasks_rude_torture_deferred_free,
902 .sync = synchronize_rcu_tasks_rude,
903 .exp_sync = synchronize_rcu_tasks_rude,
904 .call = call_rcu_tasks_rude,
905 .cb_barrier = rcu_barrier_tasks_rude,
Paul E. McKenney27c0f142020-09-15 17:08:03 -0700906 .gp_kthread_dbg = show_rcu_tasks_rude_gp_kthread,
Paul E. McKenney613b00f2021-11-23 11:53:52 -0800907 .cbflood_max = 50000,
Paul E. McKenney3d6e43c2020-03-03 15:02:50 -0800908 .fqs = NULL,
909 .stats = NULL,
910 .irq_capable = 1,
911 .name = "tasks-rude"
912};
913
Paul E. McKenney4c3f7b02022-03-17 16:16:45 -0700914#define TASKS_RUDE_OPS &tasks_rude_ops,
915
916#else // #ifdef CONFIG_TASKS_RUDE_RCU
917
918#define TASKS_RUDE_OPS
919
920#endif // #else #ifdef CONFIG_TASKS_RUDE_RCU
921
922
Paul E. McKenney40c12782022-03-17 13:29:59 -0700923#ifdef CONFIG_TASKS_TRACE_RCU
924
Paul E. McKenneyc1a76c02020-03-10 10:32:30 -0700925/*
926 * Definitions for tracing RCU-tasks torture testing.
927 */
928
929static int tasks_tracing_torture_read_lock(void)
930{
931 rcu_read_lock_trace();
932 return 0;
933}
934
935static void tasks_tracing_torture_read_unlock(int idx)
936{
937 rcu_read_unlock_trace();
938}
939
940static void rcu_tasks_tracing_torture_deferred_free(struct rcu_torture *p)
941{
942 call_rcu_tasks_trace(&p->rtort_rcu, rcu_torture_cb);
943}
944
945static struct rcu_torture_ops tasks_tracing_ops = {
946 .ttype = RCU_TASKS_TRACING_FLAVOR,
947 .init = rcu_sync_torture_init,
948 .readlock = tasks_tracing_torture_read_lock,
949 .read_delay = srcu_read_delay, /* just reuse srcu's version. */
950 .readunlock = tasks_tracing_torture_read_unlock,
Paul E. McKenneya5c095e2021-03-13 20:05:31 -0800951 .readlock_held = rcu_read_lock_trace_held,
Paul E. McKenneyc1a76c02020-03-10 10:32:30 -0700952 .get_gp_seq = rcu_no_completed,
953 .deferred_free = rcu_tasks_tracing_torture_deferred_free,
954 .sync = synchronize_rcu_tasks_trace,
955 .exp_sync = synchronize_rcu_tasks_trace,
956 .call = call_rcu_tasks_trace,
957 .cb_barrier = rcu_barrier_tasks_trace,
Paul E. McKenney27c0f142020-09-15 17:08:03 -0700958 .gp_kthread_dbg = show_rcu_tasks_trace_gp_kthread,
Paul E. McKenney613b00f2021-11-23 11:53:52 -0800959 .cbflood_max = 50000,
Paul E. McKenneyc1a76c02020-03-10 10:32:30 -0700960 .fqs = NULL,
961 .stats = NULL,
962 .irq_capable = 1,
963 .slow_gps = 1,
964 .name = "tasks-tracing"
965};
966
Paul E. McKenney40c12782022-03-17 13:29:59 -0700967#define TASKS_TRACING_OPS &tasks_tracing_ops,
968
969#else // #ifdef CONFIG_TASKS_TRACE_RCU
970
971#define TASKS_TRACING_OPS
972
973#endif // #else #ifdef CONFIG_TASKS_TRACE_RCU
974
975
Paul E. McKenneyd72193122018-05-15 15:24:41 -0700976static unsigned long rcutorture_seq_diff(unsigned long new, unsigned long old)
977{
978 if (!cur_ops->gp_diff)
979 return new - old;
980 return cur_ops->gp_diff(new, old);
981}
982
Paul E. McKenney72e9bb52006-06-27 02:54:03 -0700983/*
Paul E. McKenney8e8be452010-09-02 16:16:14 -0700984 * RCU torture priority-boost testing. Runs one real-time thread per
Paul E. McKenneyea6d9622021-03-30 16:30:32 -0700985 * CPU for moderate bursts, repeatedly starting grace periods and waiting
986 * for them to complete. If a given grace period takes too long, we assume
987 * that priority inversion has occurred.
Paul E. McKenney8e8be452010-09-02 16:16:14 -0700988 */
989
Joel Fernandes (Google)450efca2018-06-10 16:45:43 -0700990static int old_rt_runtime = -1;
991
992static void rcu_torture_disable_rt_throttle(void)
993{
994 /*
995 * Disable RT throttling so that rcutorture's boost threads don't get
996 * throttled. Only possible if rcutorture is built-in otherwise the
997 * user should manually do this by setting the sched_rt_period_us and
998 * sched_rt_runtime sysctls.
999 */
1000 if (!IS_BUILTIN(CONFIG_RCU_TORTURE_TEST) || old_rt_runtime != -1)
1001 return;
1002
1003 old_rt_runtime = sysctl_sched_rt_runtime;
1004 sysctl_sched_rt_runtime = -1;
1005}
1006
1007static void rcu_torture_enable_rt_throttle(void)
1008{
1009 if (!IS_BUILTIN(CONFIG_RCU_TORTURE_TEST) || old_rt_runtime == -1)
1010 return;
1011
1012 sysctl_sched_rt_runtime = old_rt_runtime;
1013 old_rt_runtime = -1;
1014}
1015
Paul E. McKenney063f5a42021-04-14 13:00:10 -07001016static bool rcu_torture_boost_failed(unsigned long gp_state, unsigned long *start)
Joel Fernandes (Google)3b745c82018-06-10 16:45:44 -07001017{
Paul E. McKenney0260b922021-04-08 13:01:14 -07001018 int cpu;
Paul E. McKenney5e59fba2021-01-15 13:30:38 -08001019 static int dbg_done;
Paul E. McKenney063f5a42021-04-14 13:00:10 -07001020 unsigned long end = jiffies;
Paul E. McKenneybcd4af42021-04-08 10:46:55 -07001021 bool gp_done;
Paul E. McKenney0260b922021-04-08 13:01:14 -07001022 unsigned long j;
1023 static unsigned long last_persist;
1024 unsigned long lp;
1025 unsigned long mininterval = test_boost_duration * HZ - HZ / 2;
Paul E. McKenney5e59fba2021-01-15 13:30:38 -08001026
Paul E. McKenney063f5a42021-04-14 13:00:10 -07001027 if (end - *start > mininterval) {
Paul E. McKenney7b9dad72021-04-07 17:09:37 -07001028 // Recheck after checking time to avoid false positives.
1029 smp_mb(); // Time check before grace-period check.
1030 if (cur_ops->poll_gp_state(gp_state))
1031 return false; // passed, though perhaps just barely
Paul E. McKenney0260b922021-04-08 13:01:14 -07001032 if (cur_ops->check_boost_failed && !cur_ops->check_boost_failed(gp_state, &cpu)) {
1033 // At most one persisted message per boost test.
1034 j = jiffies;
1035 lp = READ_ONCE(last_persist);
1036 if (time_after(j, lp + mininterval) && cmpxchg(&last_persist, lp, j) == lp)
1037 pr_info("Boost inversion persisted: No QS from CPU %d\n", cpu);
1038 return false; // passed on a technicality
1039 }
Joel Fernandes (Google)3b745c82018-06-10 16:45:44 -07001040 VERBOSE_TOROUT_STRING("rcu_torture_boost boosting failed");
1041 n_rcu_torture_boost_failure++;
Paul E. McKenneyea6d9622021-03-30 16:30:32 -07001042 if (!xchg(&dbg_done, 1) && cur_ops->gp_kthread_dbg) {
1043 pr_info("Boost inversion thread ->rt_priority %u gp_state %lu jiffies %lu\n",
Paul E. McKenney063f5a42021-04-14 13:00:10 -07001044 current->rt_priority, gp_state, end - *start);
Paul E. McKenney5e59fba2021-01-15 13:30:38 -08001045 cur_ops->gp_kthread_dbg();
Paul E. McKenneybcd4af42021-04-08 10:46:55 -07001046 // Recheck after print to flag grace period ending during splat.
1047 gp_done = cur_ops->poll_gp_state(gp_state);
1048 pr_info("Boost inversion: GP %lu %s.\n", gp_state,
1049 gp_done ? "ended already" : "still pending");
Joel Fernandes (Google)3b745c82018-06-10 16:45:44 -07001050
Paul E. McKenneyea6d9622021-03-30 16:30:32 -07001051 }
Joel Fernandes (Google)3b745c82018-06-10 16:45:44 -07001052
Paul E. McKenney7b9dad72021-04-07 17:09:37 -07001053 return true; // failed
Paul E. McKenney063f5a42021-04-14 13:00:10 -07001054 } else if (cur_ops->check_boost_failed && !cur_ops->check_boost_failed(gp_state, NULL)) {
1055 *start = jiffies;
Joel Fernandes (Google)3b745c82018-06-10 16:45:44 -07001056 }
1057
Paul E. McKenney7b9dad72021-04-07 17:09:37 -07001058 return false; // passed
Joel Fernandes (Google)3b745c82018-06-10 16:45:44 -07001059}
1060
Paul E. McKenney8e8be452010-09-02 16:16:14 -07001061static int rcu_torture_boost(void *arg)
1062{
Paul E. McKenney8e8be452010-09-02 16:16:14 -07001063 unsigned long endtime;
Paul E. McKenneyea6d9622021-03-30 16:30:32 -07001064 unsigned long gp_state;
1065 unsigned long gp_state_time;
Paul E. McKenney8e8be452010-09-02 16:16:14 -07001066 unsigned long oldstarttime;
Paul E. McKenney8e8be452010-09-02 16:16:14 -07001067
Paul E. McKenney5ccf60f2014-01-29 07:25:25 -08001068 VERBOSE_TOROUT_STRING("rcu_torture_boost started");
Paul E. McKenney8e8be452010-09-02 16:16:14 -07001069
1070 /* Set real-time priority. */
Peter Zijlstra8b700982020-04-22 13:10:04 +02001071 sched_set_fifo_low(current);
Paul E. McKenney8e8be452010-09-02 16:16:14 -07001072
1073 /* Each pass through the following loop does one boost-test cycle. */
1074 do {
Paul E. McKenney5e59fba2021-01-15 13:30:38 -08001075 bool failed = false; // Test failed already in this test interval
Paul E. McKenneyea6d9622021-03-30 16:30:32 -07001076 bool gp_initiated = false;
Joel Fernandes (Google)3b745c82018-06-10 16:45:44 -07001077
Joel Fernandes (Google)3b745c82018-06-10 16:45:44 -07001078 if (kthread_should_stop())
1079 goto checkwait;
1080
Paul E. McKenney8e8be452010-09-02 16:16:14 -07001081 /* Wait for the next test interval. */
Paul E. McKenneya47f9f12021-12-13 11:05:07 -08001082 oldstarttime = READ_ONCE(boost_starttime);
Paul E. McKenney3c80b402020-04-10 15:37:12 -07001083 while (time_before(jiffies, oldstarttime)) {
Paul E. McKenney0e11c8e2013-01-10 16:21:07 -08001084 schedule_timeout_interruptible(oldstarttime - jiffies);
Paul E. McKenneyab1b7882020-09-22 16:42:42 -07001085 if (stutter_wait("rcu_torture_boost"))
1086 sched_set_fifo_low(current);
Paul E. McKenney36970bb2014-01-30 15:49:29 -08001087 if (torture_must_stop())
Paul E. McKenney8e8be452010-09-02 16:16:14 -07001088 goto checkwait;
1089 }
1090
Paul E. McKenneyea6d9622021-03-30 16:30:32 -07001091 // Do one boost-test interval.
Paul E. McKenney8e8be452010-09-02 16:16:14 -07001092 endtime = oldstarttime + test_boost_duration * HZ;
Paul E. McKenney3c80b402020-04-10 15:37:12 -07001093 while (time_before(jiffies, endtime)) {
Paul E. McKenneyea6d9622021-03-30 16:30:32 -07001094 // Has current GP gone too long?
1095 if (gp_initiated && !failed && !cur_ops->poll_gp_state(gp_state))
Paul E. McKenney063f5a42021-04-14 13:00:10 -07001096 failed = rcu_torture_boost_failed(gp_state, &gp_state_time);
Paul E. McKenneyea6d9622021-03-30 16:30:32 -07001097 // If we don't have a grace period in flight, start one.
1098 if (!gp_initiated || cur_ops->poll_gp_state(gp_state)) {
1099 gp_state = cur_ops->start_gp_poll();
1100 gp_initiated = true;
1101 gp_state_time = jiffies;
Paul E. McKenney8e8be452010-09-02 16:16:14 -07001102 }
Paul E. McKenneyea6d9622021-03-30 16:30:32 -07001103 if (stutter_wait("rcu_torture_boost")) {
Paul E. McKenneyab1b7882020-09-22 16:42:42 -07001104 sched_set_fifo_low(current);
Paul E. McKenneyea6d9622021-03-30 16:30:32 -07001105 // If the grace period already ended,
1106 // we don't know when that happened, so
1107 // start over.
1108 if (cur_ops->poll_gp_state(gp_state))
1109 gp_initiated = false;
1110 }
Paul E. McKenney36970bb2014-01-30 15:49:29 -08001111 if (torture_must_stop())
Paul E. McKenney8e8be452010-09-02 16:16:14 -07001112 goto checkwait;
1113 }
1114
Paul E. McKenneyea6d9622021-03-30 16:30:32 -07001115 // In case the grace period extended beyond the end of the loop.
1116 if (gp_initiated && !failed && !cur_ops->poll_gp_state(gp_state))
Paul E. McKenney063f5a42021-04-14 13:00:10 -07001117 rcu_torture_boost_failed(gp_state, &gp_state_time);
Joel Fernandes (Google)3b745c82018-06-10 16:45:44 -07001118
1119 /*
Paul E. McKenney8e8be452010-09-02 16:16:14 -07001120 * Set the start time of the next test interval.
1121 * Yes, this is vulnerable to long delays, but such
1122 * delays simply cause a false negative for the next
1123 * interval. Besides, we are running at RT priority,
1124 * so delays should be relatively rare.
1125 */
Paul E. McKenneya47f9f12021-12-13 11:05:07 -08001126 while (oldstarttime == READ_ONCE(boost_starttime) && !kthread_should_stop()) {
Paul E. McKenney8e8be452010-09-02 16:16:14 -07001127 if (mutex_trylock(&boost_mutex)) {
Paul E. McKenney8c7ec022021-04-07 20:00:00 -07001128 if (oldstarttime == boost_starttime) {
Paul E. McKenneya47f9f12021-12-13 11:05:07 -08001129 WRITE_ONCE(boost_starttime,
1130 jiffies + test_boost_interval * HZ);
Paul E. McKenney8c7ec022021-04-07 20:00:00 -07001131 n_rcu_torture_boosts++;
1132 }
Paul E. McKenney8e8be452010-09-02 16:16:14 -07001133 mutex_unlock(&boost_mutex);
1134 break;
1135 }
1136 schedule_timeout_uninterruptible(1);
1137 }
1138
1139 /* Go do the stutter. */
Paul E. McKenneyab1b7882020-09-22 16:42:42 -07001140checkwait: if (stutter_wait("rcu_torture_boost"))
1141 sched_set_fifo_low(current);
Paul E. McKenney36970bb2014-01-30 15:49:29 -08001142 } while (!torture_must_stop());
Paul E. McKenney8e8be452010-09-02 16:16:14 -07001143
1144 /* Clean up and exit. */
Paul E. McKenneyea6d9622021-03-30 16:30:32 -07001145 while (!kthread_should_stop()) {
Paul E. McKenney7fafaac2014-01-31 17:37:28 -08001146 torture_shutdown_absorb("rcu_torture_boost");
Paul E. McKenney8e8be452010-09-02 16:16:14 -07001147 schedule_timeout_uninterruptible(1);
Paul E. McKenney7fafaac2014-01-31 17:37:28 -08001148 }
Paul E. McKenney7fafaac2014-01-31 17:37:28 -08001149 torture_kthread_stopping("rcu_torture_boost");
Paul E. McKenney8e8be452010-09-02 16:16:14 -07001150 return 0;
1151}
1152
1153/*
Paul E. McKenneybf66f182010-01-04 15:09:10 -08001154 * RCU torture force-quiescent-state kthread. Repeatedly induces
1155 * bursts of calls to force_quiescent_state(), increasing the probability
1156 * of occurrence of some important types of race conditions.
1157 */
1158static int
1159rcu_torture_fqs(void *arg)
1160{
1161 unsigned long fqs_resume_time;
1162 int fqs_burst_remaining;
Paul E. McKenneyab1b7882020-09-22 16:42:42 -07001163 int oldnice = task_nice(current);
Paul E. McKenneybf66f182010-01-04 15:09:10 -08001164
Paul E. McKenney5ccf60f2014-01-29 07:25:25 -08001165 VERBOSE_TOROUT_STRING("rcu_torture_fqs task started");
Paul E. McKenneybf66f182010-01-04 15:09:10 -08001166 do {
1167 fqs_resume_time = jiffies + fqs_stutter * HZ;
Paul E. McKenney3c80b402020-04-10 15:37:12 -07001168 while (time_before(jiffies, fqs_resume_time) &&
Paul E. McKenney93898fb2011-08-17 12:39:34 -07001169 !kthread_should_stop()) {
Paul E. McKenneybf66f182010-01-04 15:09:10 -08001170 schedule_timeout_interruptible(1);
1171 }
1172 fqs_burst_remaining = fqs_duration;
Paul E. McKenney93898fb2011-08-17 12:39:34 -07001173 while (fqs_burst_remaining > 0 &&
1174 !kthread_should_stop()) {
Paul E. McKenneybf66f182010-01-04 15:09:10 -08001175 cur_ops->fqs();
1176 udelay(fqs_holdoff);
1177 fqs_burst_remaining -= fqs_holdoff;
1178 }
Paul E. McKenneyab1b7882020-09-22 16:42:42 -07001179 if (stutter_wait("rcu_torture_fqs"))
1180 sched_set_normal(current, oldnice);
Paul E. McKenney36970bb2014-01-30 15:49:29 -08001181 } while (!torture_must_stop());
Paul E. McKenney7fafaac2014-01-31 17:37:28 -08001182 torture_kthread_stopping("rcu_torture_fqs");
Paul E. McKenneybf66f182010-01-04 15:09:10 -08001183 return 0;
1184}
1185
Paul E. McKenney11d62f02022-02-01 07:01:20 -08001186// Used by writers to randomly choose from the available grace-period primitives.
1187static int synctype[ARRAY_SIZE(rcu_torture_writer_state_names)] = { };
Paul E. McKenney18fbf302020-11-16 16:46:06 -08001188static int nsynctypes;
Paul E. McKenneya241ec62005-10-30 15:03:12 -08001189
Paul E. McKenneya241ec62005-10-30 15:03:12 -08001190/*
Paul E. McKenney18fbf302020-11-16 16:46:06 -08001191 * Determine which grace-period primitives are available.
Paul E. McKenney72e9bb52006-06-27 02:54:03 -07001192 */
Paul E. McKenney18fbf302020-11-16 16:46:06 -08001193static void rcu_torture_write_types(void)
Paul E. McKenney72e9bb52006-06-27 02:54:03 -07001194{
Paul E. McKenneyb6fe4912022-08-04 13:46:05 -07001195 bool gp_cond1 = gp_cond, gp_cond_exp1 = gp_cond_exp, gp_cond_full1 = gp_cond_full;
Paul E. McKenney8df13f02022-08-04 15:23:26 -07001196 bool gp_cond_exp_full1 = gp_cond_exp_full, gp_exp1 = gp_exp, gp_poll_exp1 = gp_poll_exp;
1197 bool gp_poll_exp_full1 = gp_poll_exp_full, gp_normal1 = gp_normal, gp_poll1 = gp_poll;
1198 bool gp_poll_full1 = gp_poll_full, gp_sync1 = gp_sync;
Paul E. McKenneya241ec62005-10-30 15:03:12 -08001199
Paul E. McKenneya48f3fa2014-03-18 15:57:41 -07001200 /* Initialize synctype[] array. If none set, take default. */
Paul E. McKenney5d7801f2022-08-23 12:11:12 -07001201 if (!gp_cond1 &&
1202 !gp_cond_exp1 &&
1203 !gp_cond_full1 &&
1204 !gp_cond_exp_full1 &&
1205 !gp_exp1 &&
1206 !gp_poll_exp1 &&
1207 !gp_poll_exp_full1 &&
1208 !gp_normal1 &&
1209 !gp_poll1 &&
1210 !gp_poll_full1 &&
1211 !gp_sync1) {
1212 gp_cond1 = true;
1213 gp_cond_exp1 = true;
1214 gp_cond_full1 = true;
1215 gp_cond_exp_full1 = true;
1216 gp_exp1 = true;
1217 gp_poll_exp1 = true;
1218 gp_poll_exp_full1 = true;
1219 gp_normal1 = true;
1220 gp_poll1 = true;
1221 gp_poll_full1 = true;
1222 gp_sync1 = true;
1223 }
Paul E. McKenneyfd56f64b2020-11-13 20:14:27 -08001224 if (gp_cond1 && cur_ops->get_gp_state && cur_ops->cond_sync) {
Paul E. McKenneya48f3fa2014-03-18 15:57:41 -07001225 synctype[nsynctypes++] = RTWS_COND_GET;
Paul E. McKenneydb0c1a82017-12-08 12:23:10 -08001226 pr_info("%s: Testing conditional GPs.\n", __func__);
Paul E. McKenneyfd56f64b2020-11-13 20:14:27 -08001227 } else if (gp_cond && (!cur_ops->get_gp_state || !cur_ops->cond_sync)) {
Paul E. McKenneye0d31a34c2017-12-01 15:22:38 -08001228 pr_alert("%s: gp_cond without primitives.\n", __func__);
Paul E. McKenneydb0c1a82017-12-08 12:23:10 -08001229 }
Paul E. McKenney11d62f02022-02-01 07:01:20 -08001230 if (gp_cond_exp1 && cur_ops->get_gp_state_exp && cur_ops->cond_sync_exp) {
1231 synctype[nsynctypes++] = RTWS_COND_GET_EXP;
1232 pr_info("%s: Testing conditional expedited GPs.\n", __func__);
1233 } else if (gp_cond_exp && (!cur_ops->get_gp_state_exp || !cur_ops->cond_sync_exp)) {
1234 pr_alert("%s: gp_cond_exp without primitives.\n", __func__);
1235 }
Paul E. McKenneyb6fe4912022-08-04 13:46:05 -07001236 if (gp_cond_full1 && cur_ops->get_gp_state && cur_ops->cond_sync_full) {
1237 synctype[nsynctypes++] = RTWS_COND_GET_FULL;
1238 pr_info("%s: Testing conditional full-state GPs.\n", __func__);
1239 } else if (gp_cond_full && (!cur_ops->get_gp_state || !cur_ops->cond_sync_full)) {
1240 pr_alert("%s: gp_cond_full without primitives.\n", __func__);
1241 }
Paul E. McKenney8df13f02022-08-04 15:23:26 -07001242 if (gp_cond_exp_full1 && cur_ops->get_gp_state_exp && cur_ops->cond_sync_exp_full) {
1243 synctype[nsynctypes++] = RTWS_COND_GET_EXP_FULL;
1244 pr_info("%s: Testing conditional full-state expedited GPs.\n", __func__);
1245 } else if (gp_cond_exp_full &&
1246 (!cur_ops->get_gp_state_exp || !cur_ops->cond_sync_exp_full)) {
1247 pr_alert("%s: gp_cond_exp_full without primitives.\n", __func__);
1248 }
Paul E. McKenneydb0c1a82017-12-08 12:23:10 -08001249 if (gp_exp1 && cur_ops->exp_sync) {
Paul E. McKenneya48f3fa2014-03-18 15:57:41 -07001250 synctype[nsynctypes++] = RTWS_EXP_SYNC;
Paul E. McKenneydb0c1a82017-12-08 12:23:10 -08001251 pr_info("%s: Testing expedited GPs.\n", __func__);
1252 } else if (gp_exp && !cur_ops->exp_sync) {
Paul E. McKenneye0d31a34c2017-12-01 15:22:38 -08001253 pr_alert("%s: gp_exp without primitives.\n", __func__);
Paul E. McKenneydb0c1a82017-12-08 12:23:10 -08001254 }
1255 if (gp_normal1 && cur_ops->deferred_free) {
Paul E. McKenneya48f3fa2014-03-18 15:57:41 -07001256 synctype[nsynctypes++] = RTWS_DEF_FREE;
Paul E. McKenneydb0c1a82017-12-08 12:23:10 -08001257 pr_info("%s: Testing asynchronous GPs.\n", __func__);
1258 } else if (gp_normal && !cur_ops->deferred_free) {
Paul E. McKenneye0d31a34c2017-12-01 15:22:38 -08001259 pr_alert("%s: gp_normal without primitives.\n", __func__);
Paul E. McKenneydb0c1a82017-12-08 12:23:10 -08001260 }
Paul E. McKenney0fd05482020-11-13 20:43:59 -08001261 if (gp_poll1 && cur_ops->start_gp_poll && cur_ops->poll_gp_state) {
1262 synctype[nsynctypes++] = RTWS_POLL_GET;
1263 pr_info("%s: Testing polling GPs.\n", __func__);
1264 } else if (gp_poll && (!cur_ops->start_gp_poll || !cur_ops->poll_gp_state)) {
1265 pr_alert("%s: gp_poll without primitives.\n", __func__);
1266 }
Paul E. McKenney76ea3642022-08-02 17:04:54 -07001267 if (gp_poll_full1 && cur_ops->start_gp_poll_full && cur_ops->poll_gp_state_full) {
1268 synctype[nsynctypes++] = RTWS_POLL_GET_FULL;
1269 pr_info("%s: Testing polling full-state GPs.\n", __func__);
1270 } else if (gp_poll_full && (!cur_ops->start_gp_poll_full || !cur_ops->poll_gp_state_full)) {
1271 pr_alert("%s: gp_poll_full without primitives.\n", __func__);
1272 }
Paul E. McKenney11d62f02022-02-01 07:01:20 -08001273 if (gp_poll_exp1 && cur_ops->start_gp_poll_exp && cur_ops->poll_gp_state_exp) {
1274 synctype[nsynctypes++] = RTWS_POLL_GET_EXP;
1275 pr_info("%s: Testing polling expedited GPs.\n", __func__);
1276 } else if (gp_poll_exp && (!cur_ops->start_gp_poll_exp || !cur_ops->poll_gp_state_exp)) {
1277 pr_alert("%s: gp_poll_exp without primitives.\n", __func__);
1278 }
Paul E. McKenney6c502b12022-08-03 12:38:51 -07001279 if (gp_poll_exp_full1 && cur_ops->start_gp_poll_exp_full && cur_ops->poll_gp_state_full) {
1280 synctype[nsynctypes++] = RTWS_POLL_GET_EXP_FULL;
1281 pr_info("%s: Testing polling full-state expedited GPs.\n", __func__);
1282 } else if (gp_poll_exp_full &&
1283 (!cur_ops->start_gp_poll_exp_full || !cur_ops->poll_gp_state_full)) {
1284 pr_alert("%s: gp_poll_exp_full without primitives.\n", __func__);
1285 }
Paul E. McKenneydb0c1a82017-12-08 12:23:10 -08001286 if (gp_sync1 && cur_ops->sync) {
Paul E. McKenneyf0bf8fa2014-03-21 16:17:56 -07001287 synctype[nsynctypes++] = RTWS_SYNC;
Paul E. McKenneydb0c1a82017-12-08 12:23:10 -08001288 pr_info("%s: Testing normal GPs.\n", __func__);
1289 } else if (gp_sync && !cur_ops->sync) {
Paul E. McKenneye0d31a34c2017-12-01 15:22:38 -08001290 pr_alert("%s: gp_sync without primitives.\n", __func__);
Paul E. McKenneydb0c1a82017-12-08 12:23:10 -08001291 }
Paul E. McKenney18fbf302020-11-16 16:46:06 -08001292}
1293
1294/*
Paul E. McKenneyccb42222022-07-29 22:05:17 -07001295 * Do the specified rcu_torture_writer() synchronous grace period,
1296 * while also testing out the polled APIs. Note well that the single-CPU
1297 * grace-period optimizations must be accounted for.
1298 */
1299static void do_rtws_sync(struct torture_random_state *trsp, void (*sync)(void))
1300{
1301 unsigned long cookie;
1302 struct rcu_gp_oldstate cookie_full;
1303 bool dopoll;
1304 bool dopoll_full;
1305 unsigned long r = torture_random(trsp);
1306
1307 dopoll = cur_ops->get_gp_state && cur_ops->poll_gp_state && !(r & 0x300);
1308 dopoll_full = cur_ops->get_gp_state_full && cur_ops->poll_gp_state_full && !(r & 0xc00);
1309 if (dopoll || dopoll_full)
1310 cpus_read_lock();
1311 if (dopoll)
1312 cookie = cur_ops->get_gp_state();
1313 if (dopoll_full)
1314 cur_ops->get_gp_state_full(&cookie_full);
Paul E. McKenneyed7d2f12022-08-01 16:57:17 -07001315 if (cur_ops->poll_need_2gp && cur_ops->poll_need_2gp(dopoll, dopoll_full))
Paul E. McKenneyccb42222022-07-29 22:05:17 -07001316 sync();
1317 sync();
1318 WARN_ONCE(dopoll && !cur_ops->poll_gp_state(cookie),
1319 "%s: Cookie check 3 failed %pS() online %*pbl.",
1320 __func__, sync, cpumask_pr_args(cpu_online_mask));
1321 WARN_ONCE(dopoll_full && !cur_ops->poll_gp_state_full(&cookie_full),
1322 "%s: Cookie check 4 failed %pS() online %*pbl",
1323 __func__, sync, cpumask_pr_args(cpu_online_mask));
1324 if (dopoll || dopoll_full)
1325 cpus_read_unlock();
1326}
1327
1328/*
Paul E. McKenney18fbf302020-11-16 16:46:06 -08001329 * RCU torture writer kthread. Repeatedly substitutes a new structure
1330 * for that pointed to by rcu_torture_current, freeing the old structure
1331 * after a series of grace periods (the "pipeline").
1332 */
1333static int
1334rcu_torture_writer(void *arg)
1335{
1336 bool boot_ended;
1337 bool can_expedite = !rcu_gp_is_expedited() && !rcu_gp_is_normal();
1338 unsigned long cookie;
Paul E. McKenney91a967f2022-07-28 15:37:05 -07001339 struct rcu_gp_oldstate cookie_full;
Paul E. McKenney18fbf302020-11-16 16:46:06 -08001340 int expediting = 0;
1341 unsigned long gp_snap;
Paul E. McKenney76ea3642022-08-02 17:04:54 -07001342 struct rcu_gp_oldstate gp_snap_full;
Paul E. McKenney18fbf302020-11-16 16:46:06 -08001343 int i;
1344 int idx;
1345 int oldnice = task_nice(current);
1346 struct rcu_torture *rp;
1347 struct rcu_torture *old_rp;
1348 static DEFINE_TORTURE_RANDOM(rand);
1349 bool stutter_waited;
1350
1351 VERBOSE_TOROUT_STRING("rcu_torture_writer task started");
1352 if (!can_expedite)
1353 pr_alert("%s" TORTURE_FLAG
1354 " GP expediting controlled from boot/sysfs for %s.\n",
1355 torture_type, cur_ops->name);
Paul E. McKenneya48f3fa2014-03-18 15:57:41 -07001356 if (WARN_ONCE(nsynctypes == 0,
David Vernet80dcee62022-03-07 14:46:57 -08001357 "%s: No update-side primitives.\n", __func__)) {
Paul E. McKenneyf0bf8fa2014-03-21 16:17:56 -07001358 /*
1359 * No updates primitives, so don't try updating.
1360 * The resulting test won't be testing much, hence the
1361 * above WARN_ONCE().
1362 */
Paul E. McKenneya48f3fa2014-03-18 15:57:41 -07001363 rcu_torture_writer_state = RTWS_STOPPING;
1364 torture_kthread_stopping("rcu_torture_writer");
David Vernet80dcee62022-03-07 14:46:57 -08001365 return 0;
Paul E. McKenneya48f3fa2014-03-18 15:57:41 -07001366 }
1367
Paul E. McKenneya241ec62005-10-30 15:03:12 -08001368 do {
Paul E. McKenneyad0dc7f2014-02-19 10:51:42 -08001369 rcu_torture_writer_state = RTWS_FIXED_DELAY;
Paul E. McKenney1eba0ef2020-11-17 14:12:24 -08001370 torture_hrtimeout_us(500, 1000, &rand);
Paul E. McKenneya71fca52009-09-18 10:28:19 -07001371 rp = rcu_torture_alloc();
1372 if (rp == NULL)
Paul E. McKenneya241ec62005-10-30 15:03:12 -08001373 continue;
1374 rp->rtort_pipe_count = 0;
Paul E. McKenneyad0dc7f2014-02-19 10:51:42 -08001375 rcu_torture_writer_state = RTWS_DELAY;
Paul E. McKenney51b11302014-01-27 11:49:39 -08001376 udelay(torture_random(&rand) & 0x3ff);
Paul E. McKenneyad0dc7f2014-02-19 10:51:42 -08001377 rcu_torture_writer_state = RTWS_REPLACE;
Paul E. McKenney0ddea0e2010-09-19 21:06:14 -07001378 old_rp = rcu_dereference_check(rcu_torture_current,
1379 current == writer_task);
Paul E. McKenneya241ec62005-10-30 15:03:12 -08001380 rp->rtort_mbtest = 1;
1381 rcu_assign_pointer(rcu_torture_current, rp);
Paul E. McKenney9b2619a2009-09-23 09:50:43 -07001382 smp_wmb(); /* Mods to old_rp must follow rcu_assign_pointer() */
Josh Triplettc8e5b162007-05-08 00:33:20 -07001383 if (old_rp) {
Paul E. McKenneya241ec62005-10-30 15:03:12 -08001384 i = old_rp->rtort_pipe_count;
1385 if (i > RCU_TORTURE_PIPE_LEN)
1386 i = RCU_TORTURE_PIPE_LEN;
1387 atomic_inc(&rcu_torture_wcount[i]);
Paul E. McKenney20248912019-12-21 10:41:48 -08001388 WRITE_ONCE(old_rp->rtort_pipe_count,
1389 old_rp->rtort_pipe_count + 1);
Paul E. McKenneyd5942312022-08-01 17:33:24 -07001390
1391 // Make sure readers block polled grace periods.
Paul E. McKenney0fd05482020-11-13 20:43:59 -08001392 if (cur_ops->get_gp_state && cur_ops->poll_gp_state) {
1393 idx = cur_ops->readlock();
1394 cookie = cur_ops->get_gp_state();
Paul E. McKenney37d6ade2022-08-02 10:22:12 -07001395 WARN_ONCE(cur_ops->poll_gp_state(cookie),
Paul E. McKenney0fd05482020-11-13 20:43:59 -08001396 "%s: Cookie check 1 failed %s(%d) %lu->%lu\n",
1397 __func__,
1398 rcu_torture_writer_state_getname(),
1399 rcu_torture_writer_state,
1400 cookie, cur_ops->get_gp_state());
Paul E. McKenneyd0eac202022-04-13 16:14:02 -07001401 if (cur_ops->get_gp_completed) {
1402 cookie = cur_ops->get_gp_completed();
1403 WARN_ON_ONCE(!cur_ops->poll_gp_state(cookie));
1404 }
Paul E. McKenney0fd05482020-11-13 20:43:59 -08001405 cur_ops->readunlock(idx);
1406 }
Paul E. McKenneyd5942312022-08-01 17:33:24 -07001407 if (cur_ops->get_gp_state_full && cur_ops->poll_gp_state_full) {
1408 idx = cur_ops->readlock();
1409 cur_ops->get_gp_state_full(&cookie_full);
1410 WARN_ONCE(cur_ops->poll_gp_state_full(&cookie_full),
1411 "%s: Cookie check 5 failed %s(%d) online %*pbl\n",
1412 __func__,
1413 rcu_torture_writer_state_getname(),
1414 rcu_torture_writer_state,
1415 cpumask_pr_args(cpu_online_mask));
1416 if (cur_ops->get_gp_completed_full) {
1417 cur_ops->get_gp_completed_full(&cookie_full);
1418 WARN_ON_ONCE(!cur_ops->poll_gp_state_full(&cookie_full));
1419 }
1420 cur_ops->readunlock(idx);
Paul E. McKenney91a967f2022-07-28 15:37:05 -07001421 }
Paul E. McKenneya48f3fa2014-03-18 15:57:41 -07001422 switch (synctype[torture_random(&rand) % nsynctypes]) {
1423 case RTWS_DEF_FREE:
Paul E. McKenneyad0dc7f2014-02-19 10:51:42 -08001424 rcu_torture_writer_state = RTWS_DEF_FREE;
Paul E. McKenney2ec1f2d92013-06-12 15:12:21 -07001425 cur_ops->deferred_free(old_rp);
Paul E. McKenneya48f3fa2014-03-18 15:57:41 -07001426 break;
1427 case RTWS_EXP_SYNC:
Paul E. McKenneyad0dc7f2014-02-19 10:51:42 -08001428 rcu_torture_writer_state = RTWS_EXP_SYNC;
Paul E. McKenneyccb42222022-07-29 22:05:17 -07001429 do_rtws_sync(&rand, cur_ops->exp_sync);
Paul E. McKenneya48f3fa2014-03-18 15:57:41 -07001430 rcu_torture_pipe_update(old_rp);
1431 break;
1432 case RTWS_COND_GET:
1433 rcu_torture_writer_state = RTWS_COND_GET;
Paul E. McKenneyfd56f64b2020-11-13 20:14:27 -08001434 gp_snap = cur_ops->get_gp_state();
Paul E. McKenneyea31fd92020-11-17 11:32:54 -08001435 torture_hrtimeout_jiffies(torture_random(&rand) % 16, &rand);
Paul E. McKenneya48f3fa2014-03-18 15:57:41 -07001436 rcu_torture_writer_state = RTWS_COND_SYNC;
1437 cur_ops->cond_sync(gp_snap);
1438 rcu_torture_pipe_update(old_rp);
1439 break;
Paul E. McKenney11d62f02022-02-01 07:01:20 -08001440 case RTWS_COND_GET_EXP:
1441 rcu_torture_writer_state = RTWS_COND_GET_EXP;
1442 gp_snap = cur_ops->get_gp_state_exp();
1443 torture_hrtimeout_jiffies(torture_random(&rand) % 16, &rand);
1444 rcu_torture_writer_state = RTWS_COND_SYNC_EXP;
1445 cur_ops->cond_sync_exp(gp_snap);
1446 rcu_torture_pipe_update(old_rp);
1447 break;
Paul E. McKenneyb6fe4912022-08-04 13:46:05 -07001448 case RTWS_COND_GET_FULL:
1449 rcu_torture_writer_state = RTWS_COND_GET_FULL;
1450 cur_ops->get_gp_state_full(&gp_snap_full);
1451 torture_hrtimeout_jiffies(torture_random(&rand) % 16, &rand);
1452 rcu_torture_writer_state = RTWS_COND_SYNC_FULL;
1453 cur_ops->cond_sync_full(&gp_snap_full);
1454 rcu_torture_pipe_update(old_rp);
1455 break;
Paul E. McKenney8df13f02022-08-04 15:23:26 -07001456 case RTWS_COND_GET_EXP_FULL:
1457 rcu_torture_writer_state = RTWS_COND_GET_EXP_FULL;
1458 cur_ops->get_gp_state_full(&gp_snap_full);
1459 torture_hrtimeout_jiffies(torture_random(&rand) % 16, &rand);
1460 rcu_torture_writer_state = RTWS_COND_SYNC_EXP_FULL;
1461 cur_ops->cond_sync_exp_full(&gp_snap_full);
1462 rcu_torture_pipe_update(old_rp);
1463 break;
Paul E. McKenney0fd05482020-11-13 20:43:59 -08001464 case RTWS_POLL_GET:
1465 rcu_torture_writer_state = RTWS_POLL_GET;
1466 gp_snap = cur_ops->start_gp_poll();
1467 rcu_torture_writer_state = RTWS_POLL_WAIT;
Paul E. McKenneyea31fd92020-11-17 11:32:54 -08001468 while (!cur_ops->poll_gp_state(gp_snap))
1469 torture_hrtimeout_jiffies(torture_random(&rand) % 16,
1470 &rand);
Paul E. McKenney0fd05482020-11-13 20:43:59 -08001471 rcu_torture_pipe_update(old_rp);
1472 break;
Paul E. McKenney76ea3642022-08-02 17:04:54 -07001473 case RTWS_POLL_GET_FULL:
1474 rcu_torture_writer_state = RTWS_POLL_GET_FULL;
1475 cur_ops->start_gp_poll_full(&gp_snap_full);
1476 rcu_torture_writer_state = RTWS_POLL_WAIT_FULL;
1477 while (!cur_ops->poll_gp_state_full(&gp_snap_full))
1478 torture_hrtimeout_jiffies(torture_random(&rand) % 16,
1479 &rand);
1480 rcu_torture_pipe_update(old_rp);
1481 break;
Paul E. McKenney11d62f02022-02-01 07:01:20 -08001482 case RTWS_POLL_GET_EXP:
1483 rcu_torture_writer_state = RTWS_POLL_GET_EXP;
1484 gp_snap = cur_ops->start_gp_poll_exp();
1485 rcu_torture_writer_state = RTWS_POLL_WAIT_EXP;
1486 while (!cur_ops->poll_gp_state_exp(gp_snap))
1487 torture_hrtimeout_jiffies(torture_random(&rand) % 16,
1488 &rand);
1489 rcu_torture_pipe_update(old_rp);
1490 break;
Paul E. McKenney6c502b12022-08-03 12:38:51 -07001491 case RTWS_POLL_GET_EXP_FULL:
1492 rcu_torture_writer_state = RTWS_POLL_GET_EXP_FULL;
1493 cur_ops->start_gp_poll_exp_full(&gp_snap_full);
1494 rcu_torture_writer_state = RTWS_POLL_WAIT_EXP_FULL;
1495 while (!cur_ops->poll_gp_state_full(&gp_snap_full))
1496 torture_hrtimeout_jiffies(torture_random(&rand) % 16,
1497 &rand);
1498 rcu_torture_pipe_update(old_rp);
1499 break;
Paul E. McKenneyf0bf8fa2014-03-21 16:17:56 -07001500 case RTWS_SYNC:
1501 rcu_torture_writer_state = RTWS_SYNC;
Paul E. McKenneyccb42222022-07-29 22:05:17 -07001502 do_rtws_sync(&rand, cur_ops->sync);
Paul E. McKenneyf0bf8fa2014-03-21 16:17:56 -07001503 rcu_torture_pipe_update(old_rp);
1504 break;
Paul E. McKenneya48f3fa2014-03-18 15:57:41 -07001505 default:
1506 WARN_ON_ONCE(1);
1507 break;
Paul E. McKenney2ec1f2d92013-06-12 15:12:21 -07001508 }
Paul E. McKenneya241ec62005-10-30 15:03:12 -08001509 }
Paul E. McKenney1b272912018-07-18 14:32:31 -07001510 WRITE_ONCE(rcu_torture_current_version,
1511 rcu_torture_current_version + 1);
Paul E. McKenney4bb3c5f2015-02-18 16:31:29 -08001512 /* Cycle through nesting levels of rcu_expedite_gp() calls. */
1513 if (can_expedite &&
1514 !(torture_random(&rand) & 0xff & (!!expediting - 1))) {
1515 WARN_ON_ONCE(expediting == 0 && rcu_gp_is_expedited());
1516 if (expediting >= 0)
1517 rcu_expedite_gp();
1518 else
1519 rcu_unexpedite_gp();
1520 if (++expediting > 3)
1521 expediting = -expediting;
Paul E. McKenneyf7c0e6a2017-12-08 11:37:24 -08001522 } else if (!can_expedite) { /* Disabled during boot, recheck. */
1523 can_expedite = !rcu_gp_is_expedited() &&
1524 !rcu_gp_is_normal();
Paul E. McKenney4bb3c5f2015-02-18 16:31:29 -08001525 }
Paul E. McKenneyad0dc7f2014-02-19 10:51:42 -08001526 rcu_torture_writer_state = RTWS_STUTTER;
Paul E. McKenney12a910e2020-11-16 16:01:50 -08001527 boot_ended = rcu_inkernel_boot_has_ended();
Paul E. McKenneyab1b7882020-09-22 16:42:42 -07001528 stutter_waited = stutter_wait("rcu_torture_writer");
1529 if (stutter_waited &&
Paul E. McKenneye22ef8d2021-12-17 12:33:53 -08001530 !atomic_read(&rcu_fwd_cb_nodelay) &&
Paul E. McKenney3432d762019-04-15 14:50:05 -07001531 !cur_ops->slow_gps &&
Paul E. McKenney59ee0322019-11-28 18:54:06 -08001532 !torture_must_stop() &&
Paul E. McKenney12a910e2020-11-16 16:01:50 -08001533 boot_ended)
Paul E. McKenney474e59b2018-08-07 14:34:44 -07001534 for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++)
Paul E. McKenneye8516c62019-04-09 11:06:32 -07001535 if (list_empty(&rcu_tortures[i].rtort_free) &&
1536 rcu_access_pointer(rcu_torture_current) !=
Paul E. McKenney34aa34b2019-05-16 16:15:16 -07001537 &rcu_tortures[i]) {
Anna-Maria Behnsen14c00172022-04-11 17:19:03 +02001538 tracing_off();
Paul E. McKenneye8516c62019-04-09 11:06:32 -07001539 WARN(1, "%s: rtort_pipe_count: %d\n", __func__, rcu_tortures[i].rtort_pipe_count);
Anna-Maria Behnsen14c00172022-04-11 17:19:03 +02001540 rcu_ftrace_dump(DUMP_ALL);
Paul E. McKenney34aa34b2019-05-16 16:15:16 -07001541 }
Paul E. McKenneyab1b7882020-09-22 16:42:42 -07001542 if (stutter_waited)
1543 sched_set_normal(current, oldnice);
Paul E. McKenney36970bb2014-01-30 15:49:29 -08001544 } while (!torture_must_stop());
Paul E. McKenneycae7cc62020-04-26 19:20:37 -07001545 rcu_torture_current = NULL; // Let stats task know that we are done.
Paul E. McKenney4bb3c5f2015-02-18 16:31:29 -08001546 /* Reset expediting back to unexpedited. */
1547 if (expediting > 0)
1548 expediting = -expediting;
1549 while (can_expedite && expediting++ < 0)
1550 rcu_unexpedite_gp();
1551 WARN_ON_ONCE(can_expedite && rcu_gp_is_expedited());
Paul E. McKenneyf7c0e6a2017-12-08 11:37:24 -08001552 if (!can_expedite)
1553 pr_alert("%s" TORTURE_FLAG
1554 " Dynamic grace-period expediting was disabled.\n",
1555 torture_type);
Paul E. McKenneyad0dc7f2014-02-19 10:51:42 -08001556 rcu_torture_writer_state = RTWS_STOPPING;
Paul E. McKenney7fafaac2014-01-31 17:37:28 -08001557 torture_kthread_stopping("rcu_torture_writer");
Paul E. McKenneya241ec62005-10-30 15:03:12 -08001558 return 0;
1559}
1560
1561/*
Josh Triplettb772e1d2006-10-04 02:17:13 -07001562 * RCU torture fake writer kthread. Repeatedly calls sync, with a random
1563 * delay between calls.
1564 */
1565static int
1566rcu_torture_fakewriter(void *arg)
1567{
Paul E. McKenney682189a2020-11-16 17:10:39 -08001568 unsigned long gp_snap;
Paul E. McKenney76ea3642022-08-02 17:04:54 -07001569 struct rcu_gp_oldstate gp_snap_full;
Paul E. McKenney51b11302014-01-27 11:49:39 -08001570 DEFINE_TORTURE_RANDOM(rand);
Josh Triplettb772e1d2006-10-04 02:17:13 -07001571
Paul E. McKenney5ccf60f2014-01-29 07:25:25 -08001572 VERBOSE_TOROUT_STRING("rcu_torture_fakewriter task started");
Linus Torvalds971eae72014-03-31 11:21:19 -07001573 set_user_nice(current, MAX_NICE);
Josh Triplettb772e1d2006-10-04 02:17:13 -07001574
David Vernet39b3cab2022-03-07 14:46:55 -08001575 if (WARN_ONCE(nsynctypes == 0,
1576 "%s: No update-side primitives.\n", __func__)) {
1577 /*
1578 * No updates primitives, so don't try updating.
1579 * The resulting test won't be testing much, hence the
1580 * above WARN_ONCE().
1581 */
1582 torture_kthread_stopping("rcu_torture_fakewriter");
1583 return 0;
1584 }
1585
Josh Triplettb772e1d2006-10-04 02:17:13 -07001586 do {
Paul E. McKenney1eba0ef2020-11-17 14:12:24 -08001587 torture_hrtimeout_jiffies(torture_random(&rand) % 10, &rand);
Paul E. McKenney72472a02012-05-29 17:50:51 -07001588 if (cur_ops->cb_barrier != NULL &&
Paul E. McKenney51b11302014-01-27 11:49:39 -08001589 torture_random(&rand) % (nfakewriters * 8) == 0) {
Paul E. McKenney72472a02012-05-29 17:50:51 -07001590 cur_ops->cb_barrier();
Paul E. McKenney682189a2020-11-16 17:10:39 -08001591 } else {
1592 switch (synctype[torture_random(&rand) % nsynctypes]) {
1593 case RTWS_DEF_FREE:
1594 break;
1595 case RTWS_EXP_SYNC:
Paul E. McKenney2ec1f2d92013-06-12 15:12:21 -07001596 cur_ops->exp_sync();
Paul E. McKenney682189a2020-11-16 17:10:39 -08001597 break;
1598 case RTWS_COND_GET:
1599 gp_snap = cur_ops->get_gp_state();
Paul E. McKenneyea31fd92020-11-17 11:32:54 -08001600 torture_hrtimeout_jiffies(torture_random(&rand) % 16, &rand);
Paul E. McKenney682189a2020-11-16 17:10:39 -08001601 cur_ops->cond_sync(gp_snap);
1602 break;
Paul E. McKenney11d62f02022-02-01 07:01:20 -08001603 case RTWS_COND_GET_EXP:
1604 gp_snap = cur_ops->get_gp_state_exp();
1605 torture_hrtimeout_jiffies(torture_random(&rand) % 16, &rand);
1606 cur_ops->cond_sync_exp(gp_snap);
1607 break;
Paul E. McKenneyb6fe4912022-08-04 13:46:05 -07001608 case RTWS_COND_GET_FULL:
1609 cur_ops->get_gp_state_full(&gp_snap_full);
1610 torture_hrtimeout_jiffies(torture_random(&rand) % 16, &rand);
1611 cur_ops->cond_sync_full(&gp_snap_full);
1612 break;
Paul E. McKenney8df13f02022-08-04 15:23:26 -07001613 case RTWS_COND_GET_EXP_FULL:
1614 cur_ops->get_gp_state_full(&gp_snap_full);
1615 torture_hrtimeout_jiffies(torture_random(&rand) % 16, &rand);
1616 cur_ops->cond_sync_exp_full(&gp_snap_full);
1617 break;
Paul E. McKenney682189a2020-11-16 17:10:39 -08001618 case RTWS_POLL_GET:
1619 gp_snap = cur_ops->start_gp_poll();
1620 while (!cur_ops->poll_gp_state(gp_snap)) {
Paul E. McKenneyea31fd92020-11-17 11:32:54 -08001621 torture_hrtimeout_jiffies(torture_random(&rand) % 16,
1622 &rand);
Paul E. McKenney682189a2020-11-16 17:10:39 -08001623 }
1624 break;
Paul E. McKenney76ea3642022-08-02 17:04:54 -07001625 case RTWS_POLL_GET_FULL:
1626 cur_ops->start_gp_poll_full(&gp_snap_full);
1627 while (!cur_ops->poll_gp_state_full(&gp_snap_full)) {
1628 torture_hrtimeout_jiffies(torture_random(&rand) % 16,
1629 &rand);
1630 }
1631 break;
Paul E. McKenney11d62f02022-02-01 07:01:20 -08001632 case RTWS_POLL_GET_EXP:
1633 gp_snap = cur_ops->start_gp_poll_exp();
1634 while (!cur_ops->poll_gp_state_exp(gp_snap)) {
1635 torture_hrtimeout_jiffies(torture_random(&rand) % 16,
1636 &rand);
1637 }
1638 break;
Paul E. McKenney6c502b12022-08-03 12:38:51 -07001639 case RTWS_POLL_GET_EXP_FULL:
1640 cur_ops->start_gp_poll_exp_full(&gp_snap_full);
1641 while (!cur_ops->poll_gp_state_full(&gp_snap_full)) {
1642 torture_hrtimeout_jiffies(torture_random(&rand) % 16,
1643 &rand);
1644 }
1645 break;
Paul E. McKenney682189a2020-11-16 17:10:39 -08001646 case RTWS_SYNC:
1647 cur_ops->sync();
1648 break;
1649 default:
1650 WARN_ON_ONCE(1);
1651 break;
1652 }
Paul E. McKenney2ec1f2d92013-06-12 15:12:21 -07001653 }
Paul E. McKenney628edaa2014-01-31 11:57:43 -08001654 stutter_wait("rcu_torture_fakewriter");
Paul E. McKenney36970bb2014-01-30 15:49:29 -08001655 } while (!torture_must_stop());
Josh Triplettb772e1d2006-10-04 02:17:13 -07001656
Paul E. McKenney7fafaac2014-01-31 17:37:28 -08001657 torture_kthread_stopping("rcu_torture_fakewriter");
Josh Triplettb772e1d2006-10-04 02:17:13 -07001658 return 0;
1659}
1660
Paul E. McKenneyf34c85852017-07-20 15:27:32 -07001661static void rcu_torture_timer_cb(struct rcu_head *rhp)
1662{
1663 kfree(rhp);
1664}
1665
Paul E. McKenney00504532020-10-29 15:08:57 -07001666// Set up and carry out testing of RCU's global memory ordering
1667static void rcu_torture_reader_do_mbchk(long myid, struct rcu_torture *rtp,
1668 struct torture_random_state *trsp)
1669{
1670 unsigned long loops;
Paul E. McKenney1afb95f2020-12-19 07:34:35 -08001671 int noc = torture_num_online_cpus();
Paul E. McKenney00504532020-10-29 15:08:57 -07001672 int rdrchked;
1673 int rdrchker;
1674 struct rcu_torture_reader_check *rtrcp; // Me.
1675 struct rcu_torture_reader_check *rtrcp_assigner; // Assigned us to do checking.
1676 struct rcu_torture_reader_check *rtrcp_chked; // Reader being checked.
1677 struct rcu_torture_reader_check *rtrcp_chker; // Reader doing checking when not me.
1678
1679 if (myid < 0)
1680 return; // Don't try this from timer handlers.
1681
1682 // Increment my counter.
1683 rtrcp = &rcu_torture_reader_mbchk[myid];
1684 WRITE_ONCE(rtrcp->rtc_myloops, rtrcp->rtc_myloops + 1);
1685
1686 // Attempt to assign someone else some checking work.
1687 rdrchked = torture_random(trsp) % nrealreaders;
1688 rtrcp_chked = &rcu_torture_reader_mbchk[rdrchked];
1689 rdrchker = torture_random(trsp) % nrealreaders;
1690 rtrcp_chker = &rcu_torture_reader_mbchk[rdrchker];
1691 if (rdrchked != myid && rdrchked != rdrchker && noc >= rdrchked && noc >= rdrchker &&
1692 smp_load_acquire(&rtrcp->rtc_chkrdr) < 0 && // Pairs with smp_store_release below.
1693 !READ_ONCE(rtp->rtort_chkp) &&
1694 !smp_load_acquire(&rtrcp_chker->rtc_assigner)) { // Pairs with smp_store_release below.
1695 rtrcp->rtc_chkloops = READ_ONCE(rtrcp_chked->rtc_myloops);
1696 WARN_ON_ONCE(rtrcp->rtc_chkrdr >= 0);
1697 rtrcp->rtc_chkrdr = rdrchked;
1698 WARN_ON_ONCE(rtrcp->rtc_ready); // This gets set after the grace period ends.
1699 if (cmpxchg_relaxed(&rtrcp_chker->rtc_assigner, NULL, rtrcp) ||
1700 cmpxchg_relaxed(&rtp->rtort_chkp, NULL, rtrcp))
1701 (void)cmpxchg_relaxed(&rtrcp_chker->rtc_assigner, rtrcp, NULL); // Back out.
1702 }
1703
1704 // If assigned some completed work, do it!
1705 rtrcp_assigner = READ_ONCE(rtrcp->rtc_assigner);
1706 if (!rtrcp_assigner || !smp_load_acquire(&rtrcp_assigner->rtc_ready))
1707 return; // No work or work not yet ready.
1708 rdrchked = rtrcp_assigner->rtc_chkrdr;
1709 if (WARN_ON_ONCE(rdrchked < 0))
1710 return;
1711 rtrcp_chked = &rcu_torture_reader_mbchk[rdrchked];
1712 loops = READ_ONCE(rtrcp_chked->rtc_myloops);
1713 atomic_inc(&n_rcu_torture_mbchk_tries);
1714 if (ULONG_CMP_LT(loops, rtrcp_assigner->rtc_chkloops))
1715 atomic_inc(&n_rcu_torture_mbchk_fail);
1716 rtrcp_assigner->rtc_chkloops = loops + ULONG_MAX / 2;
1717 rtrcp_assigner->rtc_ready = 0;
1718 smp_store_release(&rtrcp->rtc_assigner, NULL); // Someone else can assign us work.
1719 smp_store_release(&rtrcp_assigner->rtc_chkrdr, -1); // Assigner can again assign.
1720}
1721
Josh Triplettb772e1d2006-10-04 02:17:13 -07001722/*
Paul E. McKenney2397d072018-05-25 07:29:25 -07001723 * Do one extension of an RCU read-side critical section using the
1724 * current reader state in readstate (set to zero for initial entry
1725 * to extended critical section), set the new state as specified by
1726 * newstate (set to zero for final exit from extended critical section),
1727 * and random-number-generator state in trsp. If this is neither the
1728 * beginning or end of the critical section and if there was actually a
1729 * change, do a ->read_delay().
Paul E. McKenney0729fbf2008-06-25 12:24:52 -07001730 */
Paul E. McKenney2397d072018-05-25 07:29:25 -07001731static void rcutorture_one_extend(int *readstate, int newstate,
Paul E. McKenneyc116dba2018-07-13 12:09:14 -07001732 struct torture_random_state *trsp,
1733 struct rt_read_seg *rtrsp)
Paul E. McKenney0729fbf2008-06-25 12:24:52 -07001734{
Paul E. McKenney52b1fc32020-03-28 18:53:25 -07001735 unsigned long flags;
Paul E. McKenney1c3d5392021-09-22 20:49:12 -07001736 int idxnew1 = -1;
1737 int idxnew2 = -1;
1738 int idxold1 = *readstate;
1739 int idxold2 = idxold1;
Paul E. McKenney2397d072018-05-25 07:29:25 -07001740 int statesnew = ~*readstate & newstate;
1741 int statesold = *readstate & ~newstate;
1742
Paul E. McKenney1c3d5392021-09-22 20:49:12 -07001743 WARN_ON_ONCE(idxold2 < 0);
1744 WARN_ON_ONCE((idxold2 >> RCUTORTURE_RDR_SHIFT_2) > 1);
Paul E. McKenneyc116dba2018-07-13 12:09:14 -07001745 rtrsp->rt_readstate = newstate;
Paul E. McKenney2397d072018-05-25 07:29:25 -07001746
1747 /* First, put new protection in place to avoid critical-section gap. */
1748 if (statesnew & RCUTORTURE_RDR_BH)
1749 local_bh_disable();
Scott Wood71921a92021-08-20 09:42:36 +02001750 if (statesnew & RCUTORTURE_RDR_RBH)
1751 rcu_read_lock_bh();
Paul E. McKenney2397d072018-05-25 07:29:25 -07001752 if (statesnew & RCUTORTURE_RDR_IRQ)
1753 local_irq_disable();
1754 if (statesnew & RCUTORTURE_RDR_PREEMPT)
1755 preempt_disable();
Paul E. McKenney2ceebc02018-07-06 15:16:12 -07001756 if (statesnew & RCUTORTURE_RDR_SCHED)
1757 rcu_read_lock_sched();
Paul E. McKenney1c3d5392021-09-22 20:49:12 -07001758 if (statesnew & RCUTORTURE_RDR_RCU_1)
1759 idxnew1 = (cur_ops->readlock() & 0x1) << RCUTORTURE_RDR_SHIFT_1;
1760 if (statesnew & RCUTORTURE_RDR_RCU_2)
1761 idxnew2 = (cur_ops->readlock() & 0x1) << RCUTORTURE_RDR_SHIFT_2;
Paul E. McKenney2397d072018-05-25 07:29:25 -07001762
Scott Wood71921a92021-08-20 09:42:36 +02001763 /*
1764 * Next, remove old protection, in decreasing order of strength
1765 * to avoid unlock paths that aren't safe in the stronger
1766 * context. Namely: BH can not be enabled with disabled interrupts.
1767 * Additionally PREEMPT_RT requires that BH is enabled in preemptible
1768 * context.
1769 */
Paul E. McKenney2397d072018-05-25 07:29:25 -07001770 if (statesold & RCUTORTURE_RDR_IRQ)
1771 local_irq_enable();
Paul E. McKenney2397d072018-05-25 07:29:25 -07001772 if (statesold & RCUTORTURE_RDR_PREEMPT)
1773 preempt_enable();
Paul E. McKenney2ceebc02018-07-06 15:16:12 -07001774 if (statesold & RCUTORTURE_RDR_SCHED)
1775 rcu_read_unlock_sched();
Scott Wood71921a92021-08-20 09:42:36 +02001776 if (statesold & RCUTORTURE_RDR_BH)
1777 local_bh_enable();
1778 if (statesold & RCUTORTURE_RDR_RBH)
1779 rcu_read_unlock_bh();
Paul E. McKenney1c3d5392021-09-22 20:49:12 -07001780 if (statesold & RCUTORTURE_RDR_RCU_2) {
1781 cur_ops->readunlock((idxold2 >> RCUTORTURE_RDR_SHIFT_2) & 0x1);
1782 WARN_ON_ONCE(idxnew2 != -1);
1783 idxold2 = 0;
1784 }
1785 if (statesold & RCUTORTURE_RDR_RCU_1) {
Paul E. McKenney340170f2021-09-24 21:30:26 -07001786 bool lockit;
Paul E. McKenney52b1fc32020-03-28 18:53:25 -07001787
Paul E. McKenney340170f2021-09-24 21:30:26 -07001788 lockit = !cur_ops->no_pi_lock && !statesnew && !(torture_random(trsp) & 0xffff);
Paul E. McKenney52b1fc32020-03-28 18:53:25 -07001789 if (lockit)
1790 raw_spin_lock_irqsave(&current->pi_lock, flags);
Paul E. McKenney1c3d5392021-09-22 20:49:12 -07001791 cur_ops->readunlock((idxold1 >> RCUTORTURE_RDR_SHIFT_1) & 0x1);
1792 WARN_ON_ONCE(idxnew1 != -1);
1793 idxold1 = 0;
Paul E. McKenney52b1fc32020-03-28 18:53:25 -07001794 if (lockit)
1795 raw_spin_unlock_irqrestore(&current->pi_lock, flags);
1796 }
Paul E. McKenney2397d072018-05-25 07:29:25 -07001797
1798 /* Delay if neither beginning nor end and there was a change. */
1799 if ((statesnew || statesold) && *readstate && newstate)
Paul E. McKenneyc116dba2018-07-13 12:09:14 -07001800 cur_ops->read_delay(trsp, rtrsp);
Paul E. McKenney2397d072018-05-25 07:29:25 -07001801
1802 /* Update the reader state. */
Paul E. McKenney1c3d5392021-09-22 20:49:12 -07001803 if (idxnew1 == -1)
1804 idxnew1 = idxold1 & RCUTORTURE_RDR_MASK_1;
1805 WARN_ON_ONCE(idxnew1 < 0);
1806 if (WARN_ON_ONCE((idxnew1 >> RCUTORTURE_RDR_SHIFT_1) > 1))
1807 pr_info("Unexpected idxnew1 value of %#x\n", idxnew1);
1808 if (idxnew2 == -1)
1809 idxnew2 = idxold2 & RCUTORTURE_RDR_MASK_2;
1810 WARN_ON_ONCE(idxnew2 < 0);
1811 WARN_ON_ONCE((idxnew2 >> RCUTORTURE_RDR_SHIFT_2) > 1);
1812 *readstate = idxnew1 | idxnew2 | newstate;
1813 WARN_ON_ONCE(*readstate < 0);
1814 if (WARN_ON_ONCE((*readstate >> RCUTORTURE_RDR_SHIFT_2) > 1))
1815 pr_info("Unexpected idxnew2 value of %#x\n", idxnew2);
Paul E. McKenney2397d072018-05-25 07:29:25 -07001816}
1817
1818/* Return the biggest extendables mask given current RCU and boot parameters. */
1819static int rcutorture_extend_mask_max(void)
1820{
1821 int mask;
1822
1823 WARN_ON_ONCE(extendables & ~RCUTORTURE_MAX_EXTEND);
1824 mask = extendables & RCUTORTURE_MAX_EXTEND & cur_ops->extendables;
Paul E. McKenney1c3d5392021-09-22 20:49:12 -07001825 mask = mask | RCUTORTURE_RDR_RCU_1 | RCUTORTURE_RDR_RCU_2;
Paul E. McKenney2397d072018-05-25 07:29:25 -07001826 return mask;
1827}
1828
1829/* Return a random protection state mask, but with at least one bit set. */
1830static int
1831rcutorture_extend_mask(int oldmask, struct torture_random_state *trsp)
1832{
1833 int mask = rcutorture_extend_mask_max();
Paul E. McKenneybf1bef52018-06-10 08:50:09 -07001834 unsigned long randmask1 = torture_random(trsp) >> 8;
Paul E. McKenneyc116dba2018-07-13 12:09:14 -07001835 unsigned long randmask2 = randmask1 >> 3;
Scott Wood71921a92021-08-20 09:42:36 +02001836 unsigned long preempts = RCUTORTURE_RDR_PREEMPT | RCUTORTURE_RDR_SCHED;
1837 unsigned long preempts_irq = preempts | RCUTORTURE_RDR_IRQ;
1838 unsigned long bhs = RCUTORTURE_RDR_BH | RCUTORTURE_RDR_RBH;
Paul E. McKenney2397d072018-05-25 07:29:25 -07001839
Paul E. McKenney1c3d5392021-09-22 20:49:12 -07001840 WARN_ON_ONCE(mask >> RCUTORTURE_RDR_SHIFT_1);
Paul E. McKenneya3b0e1e52019-02-28 15:06:13 -08001841 /* Mostly only one bit (need preemption!), sometimes lots of bits. */
Paul E. McKenneyc116dba2018-07-13 12:09:14 -07001842 if (!(randmask1 & 0x7))
Paul E. McKenneybf1bef52018-06-10 08:50:09 -07001843 mask = mask & randmask2;
1844 else
1845 mask = mask & (1 << (randmask2 % RCUTORTURE_RDR_NBITS));
Scott Wood71921a92021-08-20 09:42:36 +02001846
Paul E. McKenney1c3d5392021-09-22 20:49:12 -07001847 // Can't have nested RCU reader without outer RCU reader.
1848 if (!(mask & RCUTORTURE_RDR_RCU_1) && (mask & RCUTORTURE_RDR_RCU_2)) {
1849 if (oldmask & RCUTORTURE_RDR_RCU_1)
1850 mask &= ~RCUTORTURE_RDR_RCU_2;
1851 else
1852 mask |= RCUTORTURE_RDR_RCU_1;
1853 }
1854
Scott Wood71921a92021-08-20 09:42:36 +02001855 /*
1856 * Can't enable bh w/irq disabled.
1857 */
1858 if (mask & RCUTORTURE_RDR_IRQ)
1859 mask |= oldmask & bhs;
1860
1861 /*
1862 * Ideally these sequences would be detected in debug builds
1863 * (regardless of RT), but until then don't stop testing
1864 * them on non-RT.
1865 */
1866 if (IS_ENABLED(CONFIG_PREEMPT_RT)) {
1867 /* Can't modify BH in atomic context */
1868 if (oldmask & preempts_irq)
1869 mask &= ~bhs;
1870 if ((oldmask | mask) & preempts_irq)
1871 mask |= oldmask & bhs;
1872 }
1873
Paul E. McKenney1c3d5392021-09-22 20:49:12 -07001874 return mask ?: RCUTORTURE_RDR_RCU_1;
Paul E. McKenney2397d072018-05-25 07:29:25 -07001875}
1876
1877/*
1878 * Do a randomly selected number of extensions of an existing RCU read-side
1879 * critical section.
1880 */
Paul E. McKenneyc116dba2018-07-13 12:09:14 -07001881static struct rt_read_seg *
1882rcutorture_loop_extend(int *readstate, struct torture_random_state *trsp,
1883 struct rt_read_seg *rtrsp)
Paul E. McKenney2397d072018-05-25 07:29:25 -07001884{
1885 int i;
Paul E. McKenneyc116dba2018-07-13 12:09:14 -07001886 int j;
Paul E. McKenney2397d072018-05-25 07:29:25 -07001887 int mask = rcutorture_extend_mask_max();
1888
1889 WARN_ON_ONCE(!*readstate); /* -Existing- RCU read-side critsect! */
1890 if (!((mask - 1) & mask))
Paul E. McKenneyc116dba2018-07-13 12:09:14 -07001891 return rtrsp; /* Current RCU reader not extendable. */
1892 /* Bias towards larger numbers of loops. */
1893 i = (torture_random(trsp) >> 3);
1894 i = ((i | (i >> 3)) & RCUTORTURE_RDR_MAX_LOOPS) + 1;
1895 for (j = 0; j < i; j++) {
Paul E. McKenney2397d072018-05-25 07:29:25 -07001896 mask = rcutorture_extend_mask(*readstate, trsp);
Paul E. McKenneyc116dba2018-07-13 12:09:14 -07001897 rcutorture_one_extend(readstate, mask, trsp, &rtrsp[j]);
Paul E. McKenney2397d072018-05-25 07:29:25 -07001898 }
Paul E. McKenneyc116dba2018-07-13 12:09:14 -07001899 return &rtrsp[j];
Paul E. McKenney2397d072018-05-25 07:29:25 -07001900}
1901
1902/*
Paul E. McKenney6b06aa72018-05-22 10:56:05 -07001903 * Do one read-side critical section, returning false if there was
1904 * no data to read. Can be invoked both from process context and
1905 * from a timer handler.
1906 */
Paul E. McKenney00504532020-10-29 15:08:57 -07001907static bool rcu_torture_one_read(struct torture_random_state *trsp, long myid)
Paul E. McKenney6b06aa72018-05-22 10:56:05 -07001908{
Paul E. McKenney967c2982022-08-24 18:57:45 -07001909 bool checkpolling = !(torture_random(trsp) & 0xfff);
Paul E. McKenneybc480a62020-11-15 12:45:57 -08001910 unsigned long cookie;
Paul E. McKenneyf4754ad2022-08-03 16:40:48 -07001911 struct rcu_gp_oldstate cookie_full;
Paul E. McKenneyc116dba2018-07-13 12:09:14 -07001912 int i;
Paul E. McKenney917963d2014-11-21 17:10:16 -08001913 unsigned long started;
Paul E. McKenney6b80da42014-11-21 14:19:26 -08001914 unsigned long completed;
Paul E. McKenney2397d072018-05-25 07:29:25 -07001915 int newstate;
Paul E. McKenney0729fbf2008-06-25 12:24:52 -07001916 struct rcu_torture *p;
1917 int pipe_count;
Paul E. McKenney2397d072018-05-25 07:29:25 -07001918 int readstate = 0;
Paul E. McKenneyc116dba2018-07-13 12:09:14 -07001919 struct rt_read_seg rtseg[RCUTORTURE_RDR_MAX_SEGS] = { { 0 } };
1920 struct rt_read_seg *rtrsp = &rtseg[0];
1921 struct rt_read_seg *rtrsp1;
Paul E. McKenney52494532012-11-14 16:26:40 -08001922 unsigned long long ts;
Paul E. McKenney0729fbf2008-06-25 12:24:52 -07001923
Paul E. McKenney77522752020-06-11 16:43:14 -07001924 WARN_ON_ONCE(!rcu_is_watching());
Paul E. McKenney2397d072018-05-25 07:29:25 -07001925 newstate = rcutorture_extend_mask(readstate, trsp);
Paul E. McKenneyc116dba2018-07-13 12:09:14 -07001926 rcutorture_one_extend(&readstate, newstate, trsp, rtrsp++);
Paul E. McKenney967c2982022-08-24 18:57:45 -07001927 if (checkpolling) {
1928 if (cur_ops->get_gp_state && cur_ops->poll_gp_state)
1929 cookie = cur_ops->get_gp_state();
1930 if (cur_ops->get_gp_state_full && cur_ops->poll_gp_state_full)
1931 cur_ops->get_gp_state_full(&cookie_full);
1932 }
Paul E. McKenney17ef2fe2018-04-27 11:39:34 -07001933 started = cur_ops->get_gp_seq();
Steven Rostedte4aa0da2013-02-04 13:36:13 -05001934 ts = rcu_trace_clock_local();
Paul E. McKenney632ee202010-02-22 17:04:45 -08001935 p = rcu_dereference_check(rcu_torture_current,
Paul E. McKenneya5c095e2021-03-13 20:05:31 -08001936 !cur_ops->readlock_held || cur_ops->readlock_held());
Paul E. McKenney0729fbf2008-06-25 12:24:52 -07001937 if (p == NULL) {
Paul E. McKenney6b06aa72018-05-22 10:56:05 -07001938 /* Wait for rcu_torture_writer to get underway */
Paul E. McKenneyc116dba2018-07-13 12:09:14 -07001939 rcutorture_one_extend(&readstate, 0, trsp, rtrsp);
Paul E. McKenney6b06aa72018-05-22 10:56:05 -07001940 return false;
Paul E. McKenney0729fbf2008-06-25 12:24:52 -07001941 }
1942 if (p->rtort_mbtest == 0)
1943 atomic_inc(&n_rcu_torture_mberror);
Paul E. McKenney00504532020-10-29 15:08:57 -07001944 rcu_torture_reader_do_mbchk(myid, p, trsp);
Paul E. McKenneyc116dba2018-07-13 12:09:14 -07001945 rtrsp = rcutorture_loop_extend(&readstate, trsp, rtrsp);
Paul E. McKenney0729fbf2008-06-25 12:24:52 -07001946 preempt_disable();
Paul E. McKenney20248912019-12-21 10:41:48 -08001947 pipe_count = READ_ONCE(p->rtort_pipe_count);
Paul E. McKenney0729fbf2008-06-25 12:24:52 -07001948 if (pipe_count > RCU_TORTURE_PIPE_LEN) {
1949 /* Should not happen, but... */
1950 pipe_count = RCU_TORTURE_PIPE_LEN;
1951 }
Paul E. McKenney17ef2fe2018-04-27 11:39:34 -07001952 completed = cur_ops->get_gp_seq();
Paul E. McKenney52494532012-11-14 16:26:40 -08001953 if (pipe_count > 1) {
Paul E. McKenney6b06aa72018-05-22 10:56:05 -07001954 do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu,
1955 ts, started, completed);
Paul E. McKenney274529b2016-03-21 19:46:04 -07001956 rcu_ftrace_dump(DUMP_ALL);
Paul E. McKenney52494532012-11-14 16:26:40 -08001957 }
Rusty Russelldd17c8f2009-10-29 22:34:15 +09001958 __this_cpu_inc(rcu_torture_count[pipe_count]);
Paul E. McKenneyd72193122018-05-15 15:24:41 -07001959 completed = rcutorture_seq_diff(completed, started);
Paul E. McKenney0729fbf2008-06-25 12:24:52 -07001960 if (completed > RCU_TORTURE_PIPE_LEN) {
1961 /* Should not happen, but... */
1962 completed = RCU_TORTURE_PIPE_LEN;
1963 }
Rusty Russelldd17c8f2009-10-29 22:34:15 +09001964 __this_cpu_inc(rcu_torture_batch[completed]);
Paul E. McKenney0729fbf2008-06-25 12:24:52 -07001965 preempt_enable();
Paul E. McKenney967c2982022-08-24 18:57:45 -07001966 if (checkpolling) {
1967 if (cur_ops->get_gp_state && cur_ops->poll_gp_state)
1968 WARN_ONCE(cur_ops->poll_gp_state(cookie),
1969 "%s: Cookie check 2 failed %s(%d) %lu->%lu\n",
1970 __func__,
1971 rcu_torture_writer_state_getname(),
1972 rcu_torture_writer_state,
1973 cookie, cur_ops->get_gp_state());
1974 if (cur_ops->get_gp_state_full && cur_ops->poll_gp_state_full)
1975 WARN_ONCE(cur_ops->poll_gp_state_full(&cookie_full),
1976 "%s: Cookie check 6 failed %s(%d) online %*pbl\n",
1977 __func__,
1978 rcu_torture_writer_state_getname(),
1979 rcu_torture_writer_state,
1980 cpumask_pr_args(cpu_online_mask));
1981 }
Paul E. McKenneyc116dba2018-07-13 12:09:14 -07001982 rcutorture_one_extend(&readstate, 0, trsp, rtrsp);
Paul E. McKenney902d82e62021-09-22 20:31:44 -07001983 WARN_ON_ONCE(readstate);
Paul E. McKenneyd6855142020-08-11 10:33:39 -07001984 // This next splat is expected behavior if leakpointer, especially
1985 // for CONFIG_RCU_STRICT_GRACE_PERIOD=y kernels.
1986 WARN_ON_ONCE(leakpointer && READ_ONCE(p->rtort_pipe_count) > 1);
Paul E. McKenneyc116dba2018-07-13 12:09:14 -07001987
1988 /* If error or close call, record the sequence of reader protections. */
1989 if ((pipe_count > 1 || completed > 1) && !xchg(&err_segs_recorded, 1)) {
1990 i = 0;
1991 for (rtrsp1 = &rtseg[0]; rtrsp1 < rtrsp; rtrsp1++)
1992 err_segs[i++] = *rtrsp1;
1993 rt_read_nsegs = i;
1994 }
1995
Paul E. McKenney6b06aa72018-05-22 10:56:05 -07001996 return true;
1997}
1998
Paul E. McKenney3025520e2018-05-22 11:38:47 -07001999static DEFINE_TORTURE_RANDOM_PERCPU(rcu_torture_timer_rand);
2000
Paul E. McKenney6b06aa72018-05-22 10:56:05 -07002001/*
Paul E. McKenneya241ec62005-10-30 15:03:12 -08002002 * RCU torture reader from timer handler. Dereferences rcu_torture_current,
2003 * incrementing the corresponding element of the pipeline array. The
2004 * counter in the element should never be greater than 1, otherwise, the
2005 * RCU implementation is broken.
2006 */
2007static void rcu_torture_timer(struct timer_list *unused)
2008{
Paul E. McKenney8da9a592018-05-22 11:17:51 -07002009 atomic_long_inc(&n_rcu_torture_timers);
Paul E. McKenney00504532020-10-29 15:08:57 -07002010 (void)rcu_torture_one_read(this_cpu_ptr(&rcu_torture_timer_rand), -1);
Paul E. McKenneyf34c85852017-07-20 15:27:32 -07002011
2012 /* Test call_rcu() invocation from interrupt handler. */
2013 if (cur_ops->call) {
2014 struct rcu_head *rhp = kmalloc(sizeof(*rhp), GFP_NOWAIT);
2015
2016 if (rhp)
2017 cur_ops->call(rhp, rcu_torture_timer_cb);
2018 }
Paul E. McKenney0729fbf2008-06-25 12:24:52 -07002019}
2020
2021/*
Paul E. McKenneya241ec62005-10-30 15:03:12 -08002022 * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current,
2023 * incrementing the corresponding element of the pipeline array. The
2024 * counter in the element should never be greater than 1, otherwise, the
2025 * RCU implementation is broken.
2026 */
2027static int
2028rcu_torture_reader(void *arg)
2029{
Paul E. McKenney444da512018-07-04 14:14:42 -07002030 unsigned long lastsleep = jiffies;
Paul E. McKenneyc04dd092018-07-23 14:16:47 -07002031 long myid = (long)arg;
2032 int mynumonline = myid;
Paul E. McKenney51b11302014-01-27 11:49:39 -08002033 DEFINE_TORTURE_RANDOM(rand);
Paul E. McKenney0729fbf2008-06-25 12:24:52 -07002034 struct timer_list t;
Paul E. McKenneya241ec62005-10-30 15:03:12 -08002035
Paul E. McKenney5ccf60f2014-01-29 07:25:25 -08002036 VERBOSE_TOROUT_STRING("rcu_torture_reader task started");
Linus Torvalds971eae72014-03-31 11:21:19 -07002037 set_user_nice(current, MAX_NICE);
Paul E. McKenney0acc5122009-06-25 09:08:17 -07002038 if (irqreader && cur_ops->irq_capable)
Kees Cookfd30b712017-10-22 17:58:54 -07002039 timer_setup_on_stack(&t, rcu_torture_timer, 0);
Paul E. McKenneyd38e6dc2019-07-28 12:00:48 -07002040 tick_dep_set_task(current, TICK_DEP_BIT_RCU);
Paul E. McKenneya241ec62005-10-30 15:03:12 -08002041 do {
Paul E. McKenney0acc5122009-06-25 09:08:17 -07002042 if (irqreader && cur_ops->irq_capable) {
Paul E. McKenney0729fbf2008-06-25 12:24:52 -07002043 if (!timer_pending(&t))
Paul E. McKenney6155fec2010-02-22 17:05:04 -08002044 mod_timer(&t, jiffies + 1);
Paul E. McKenney0729fbf2008-06-25 12:24:52 -07002045 }
Paul E. McKenney00504532020-10-29 15:08:57 -07002046 if (!rcu_torture_one_read(&rand, myid) && !torture_must_stop())
Paul E. McKenneya241ec62005-10-30 15:03:12 -08002047 schedule_timeout_interruptible(HZ);
Paul E. McKenneyd38e6dc2019-07-28 12:00:48 -07002048 if (time_after(jiffies, lastsleep) && !torture_must_stop()) {
Paul E. McKenney1eba0ef2020-11-17 14:12:24 -08002049 torture_hrtimeout_us(500, 1000, &rand);
Paul E. McKenney444da512018-07-04 14:14:42 -07002050 lastsleep = jiffies + 10;
2051 }
Paul E. McKenney1afb95f2020-12-19 07:34:35 -08002052 while (torture_num_online_cpus() < mynumonline && !torture_must_stop())
Paul E. McKenneyc04dd092018-07-23 14:16:47 -07002053 schedule_timeout_interruptible(HZ / 5);
Paul E. McKenney628edaa2014-01-31 11:57:43 -08002054 stutter_wait("rcu_torture_reader");
Paul E. McKenney36970bb2014-01-30 15:49:29 -08002055 } while (!torture_must_stop());
Thomas Gleixner424c1b62014-03-23 08:58:27 -07002056 if (irqreader && cur_ops->irq_capable) {
Paul E. McKenney0729fbf2008-06-25 12:24:52 -07002057 del_timer_sync(&t);
Thomas Gleixner424c1b62014-03-23 08:58:27 -07002058 destroy_timer_on_stack(&t);
2059 }
Paul E. McKenneyd38e6dc2019-07-28 12:00:48 -07002060 tick_dep_clear_task(current, TICK_DEP_BIT_RCU);
Paul E. McKenney7fafaac2014-01-31 17:37:28 -08002061 torture_kthread_stopping("rcu_torture_reader");
Paul E. McKenneya241ec62005-10-30 15:03:12 -08002062 return 0;
2063}
2064
2065/*
Paul E. McKenney2c4319b2020-09-23 17:39:46 -07002066 * Randomly Toggle CPUs' callback-offload state. This uses hrtimers to
2067 * increase race probabilities and fuzzes the interval between toggling.
2068 */
2069static int rcu_nocb_toggle(void *arg)
2070{
2071 int cpu;
2072 int maxcpu = -1;
2073 int oldnice = task_nice(current);
2074 long r;
2075 DEFINE_TORTURE_RANDOM(rand);
2076 ktime_t toggle_delay;
2077 unsigned long toggle_fuzz;
2078 ktime_t toggle_interval = ms_to_ktime(nocbs_toggle);
2079
2080 VERBOSE_TOROUT_STRING("rcu_nocb_toggle task started");
2081 while (!rcu_inkernel_boot_has_ended())
2082 schedule_timeout_interruptible(HZ / 10);
2083 for_each_online_cpu(cpu)
2084 maxcpu = cpu;
2085 WARN_ON(maxcpu < 0);
2086 if (toggle_interval > ULONG_MAX)
2087 toggle_fuzz = ULONG_MAX >> 3;
2088 else
2089 toggle_fuzz = toggle_interval >> 3;
2090 if (toggle_fuzz <= 0)
2091 toggle_fuzz = NSEC_PER_USEC;
2092 do {
2093 r = torture_random(&rand);
2094 cpu = (r >> 4) % (maxcpu + 1);
2095 if (r & 0x1) {
2096 rcu_nocb_cpu_offload(cpu);
2097 atomic_long_inc(&n_nocb_offload);
2098 } else {
2099 rcu_nocb_cpu_deoffload(cpu);
2100 atomic_long_inc(&n_nocb_deoffload);
2101 }
2102 toggle_delay = torture_random(&rand) % toggle_fuzz + toggle_interval;
2103 set_current_state(TASK_INTERRUPTIBLE);
2104 schedule_hrtimeout(&toggle_delay, HRTIMER_MODE_REL);
2105 if (stutter_wait("rcu_nocb_toggle"))
2106 sched_set_normal(current, oldnice);
2107 } while (!torture_must_stop());
2108 torture_kthread_stopping("rcu_nocb_toggle");
2109 return 0;
2110}
2111
2112/*
Joe Percheseea203f2014-07-14 09:16:15 -04002113 * Print torture statistics. Caller must ensure that there is only
2114 * one call to this function at a given time!!! This is normally
2115 * accomplished by relying on the module system to only have one copy
2116 * of the module loaded, and then by giving the rcu_torture_stats
2117 * kthread full control (or the init/cleanup functions when rcu_torture_stats
2118 * thread is not running).
Paul E. McKenneya241ec62005-10-30 15:03:12 -08002119 */
Chen Gangd1008952013-11-07 10:30:25 +08002120static void
Joe Percheseea203f2014-07-14 09:16:15 -04002121rcu_torture_stats_print(void)
Paul E. McKenneya241ec62005-10-30 15:03:12 -08002122{
Paul E. McKenneya241ec62005-10-30 15:03:12 -08002123 int cpu;
2124 int i;
2125 long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
2126 long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
Paul E. McKenney5396d312020-01-08 19:58:13 -08002127 struct rcu_torture *rtcp;
Paul E. McKenneyad0dc7f2014-02-19 10:51:42 -08002128 static unsigned long rtcv_snap = ULONG_MAX;
Paul E. McKenney0032f4e2017-08-30 10:40:17 -07002129 static bool splatted;
Paul E. McKenney4ffa6692016-06-30 11:56:38 -07002130 struct task_struct *wtp;
Paul E. McKenneya241ec62005-10-30 15:03:12 -08002131
KAMEZAWA Hiroyuki0a945022006-03-28 01:56:37 -08002132 for_each_possible_cpu(cpu) {
Paul E. McKenneya241ec62005-10-30 15:03:12 -08002133 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
Paul E. McKenneyf042a432020-01-03 16:27:00 -08002134 pipesummary[i] += READ_ONCE(per_cpu(rcu_torture_count, cpu)[i]);
2135 batchsummary[i] += READ_ONCE(per_cpu(rcu_torture_batch, cpu)[i]);
Paul E. McKenneya241ec62005-10-30 15:03:12 -08002136 }
2137 }
Paul E. McKenney8c0666d2022-05-20 13:18:16 -07002138 for (i = RCU_TORTURE_PIPE_LEN; i >= 0; i--) {
Paul E. McKenneya241ec62005-10-30 15:03:12 -08002139 if (pipesummary[i] != 0)
2140 break;
2141 }
Joe Percheseea203f2014-07-14 09:16:15 -04002142
2143 pr_alert("%s%s ", torture_type, TORTURE_FLAG);
Paul E. McKenney5396d312020-01-08 19:58:13 -08002144 rtcp = rcu_access_pointer(rcu_torture_current);
Paul E. McKenney354ea052019-05-25 12:36:53 -07002145 pr_cont("rtc: %p %s: %lu tfle: %d rta: %d rtaf: %d rtf: %d ",
Paul E. McKenney5396d312020-01-08 19:58:13 -08002146 rtcp,
2147 rtcp && !rcu_stall_is_suppressed_at_boot() ? "ver" : "VER",
Joe Percheseea203f2014-07-14 09:16:15 -04002148 rcu_torture_current_version,
2149 list_empty(&rcu_torture_freelist),
2150 atomic_read(&n_rcu_torture_alloc),
2151 atomic_read(&n_rcu_torture_alloc_fail),
2152 atomic_read(&n_rcu_torture_free));
Paul E. McKenney00504532020-10-29 15:08:57 -07002153 pr_cont("rtmbe: %d rtmbkf: %d/%d rtbe: %ld rtbke: %ld rtbre: %ld ",
Joe Percheseea203f2014-07-14 09:16:15 -04002154 atomic_read(&n_rcu_torture_mberror),
Paul E. McKenney00504532020-10-29 15:08:57 -07002155 atomic_read(&n_rcu_torture_mbchk_fail), atomic_read(&n_rcu_torture_mbchk_tries),
SeongJae Park472213a2016-08-13 15:54:35 +09002156 n_rcu_torture_barrier_error,
Joe Percheseea203f2014-07-14 09:16:15 -04002157 n_rcu_torture_boost_ktrerror,
2158 n_rcu_torture_boost_rterror);
2159 pr_cont("rtbf: %ld rtb: %ld nt: %ld ",
2160 n_rcu_torture_boost_failure,
2161 n_rcu_torture_boosts,
Paul E. McKenney8da9a592018-05-22 11:17:51 -07002162 atomic_long_read(&n_rcu_torture_timers));
Joe Percheseea203f2014-07-14 09:16:15 -04002163 torture_onoff_stats();
Paul E. McKenney4a5f1332020-04-24 11:21:40 -07002164 pr_cont("barrier: %ld/%ld:%ld ",
Paul E. McKenneyc9527be2020-02-18 13:41:02 -08002165 data_race(n_barrier_successes),
2166 data_race(n_barrier_attempts),
2167 data_race(n_rcu_torture_barrier_error));
Paul E. McKenneyf7590812020-12-21 11:17:16 -08002168 pr_cont("read-exits: %ld ", data_race(n_read_exits)); // Statistic.
Paul E. McKenney2c4319b2020-09-23 17:39:46 -07002169 pr_cont("nocb-toggles: %ld:%ld\n",
2170 atomic_long_read(&n_nocb_offload), atomic_long_read(&n_nocb_deoffload));
Joe Percheseea203f2014-07-14 09:16:15 -04002171
2172 pr_alert("%s%s ", torture_type, TORTURE_FLAG);
Paul E. McKenney8b5ddf82019-08-14 12:02:40 -07002173 if (atomic_read(&n_rcu_torture_mberror) ||
Paul E. McKenney00504532020-10-29 15:08:57 -07002174 atomic_read(&n_rcu_torture_mbchk_fail) ||
Paul E. McKenney8b5ddf82019-08-14 12:02:40 -07002175 n_rcu_torture_barrier_error || n_rcu_torture_boost_ktrerror ||
2176 n_rcu_torture_boost_rterror || n_rcu_torture_boost_failure ||
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08002177 i > 1) {
Joe Percheseea203f2014-07-14 09:16:15 -04002178 pr_cont("%s", "!!! ");
Paul E. McKenney996417d2005-11-18 01:10:50 -08002179 atomic_inc(&n_rcu_torture_error);
Paul E. McKenney8b5ddf82019-08-14 12:02:40 -07002180 WARN_ON_ONCE(atomic_read(&n_rcu_torture_mberror));
Paul E. McKenney00504532020-10-29 15:08:57 -07002181 WARN_ON_ONCE(atomic_read(&n_rcu_torture_mbchk_fail));
Paul E. McKenney8b5ddf82019-08-14 12:02:40 -07002182 WARN_ON_ONCE(n_rcu_torture_barrier_error); // rcu_barrier()
2183 WARN_ON_ONCE(n_rcu_torture_boost_ktrerror); // no boost kthread
2184 WARN_ON_ONCE(n_rcu_torture_boost_rterror); // can't set RT prio
Paul E. McKenney5e59fba2021-01-15 13:30:38 -08002185 WARN_ON_ONCE(n_rcu_torture_boost_failure); // boost failed (TIMER_SOFTIRQ RT prio?)
Paul E. McKenney8b5ddf82019-08-14 12:02:40 -07002186 WARN_ON_ONCE(i > 1); // Too-short grace period
Paul E. McKenney996417d2005-11-18 01:10:50 -08002187 }
Joe Percheseea203f2014-07-14 09:16:15 -04002188 pr_cont("Reader Pipe: ");
Paul E. McKenneya241ec62005-10-30 15:03:12 -08002189 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
Joe Percheseea203f2014-07-14 09:16:15 -04002190 pr_cont(" %ld", pipesummary[i]);
2191 pr_cont("\n");
2192
2193 pr_alert("%s%s ", torture_type, TORTURE_FLAG);
2194 pr_cont("Reader Batch: ");
Paul E. McKenney72e9bb52006-06-27 02:54:03 -07002195 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
Joe Percheseea203f2014-07-14 09:16:15 -04002196 pr_cont(" %ld", batchsummary[i]);
2197 pr_cont("\n");
2198
2199 pr_alert("%s%s ", torture_type, TORTURE_FLAG);
2200 pr_cont("Free-Block Circulation: ");
Paul E. McKenneya241ec62005-10-30 15:03:12 -08002201 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
Joe Percheseea203f2014-07-14 09:16:15 -04002202 pr_cont(" %d", atomic_read(&rcu_torture_wcount[i]));
Paul E. McKenneya241ec62005-10-30 15:03:12 -08002203 }
Joe Percheseea203f2014-07-14 09:16:15 -04002204 pr_cont("\n");
2205
Josh Triplettc8e5b162007-05-08 00:33:20 -07002206 if (cur_ops->stats)
Joe Percheseea203f2014-07-14 09:16:15 -04002207 cur_ops->stats();
Paul E. McKenneyad0dc7f2014-02-19 10:51:42 -08002208 if (rtcv_snap == rcu_torture_current_version &&
Paul E. McKenney5396d312020-01-08 19:58:13 -08002209 rcu_access_pointer(rcu_torture_current) &&
2210 !rcu_stall_is_suppressed()) {
Paul E. McKenney7f6733c2017-04-18 17:17:35 -07002211 int __maybe_unused flags = 0;
Paul E. McKenneyaebc8262018-05-01 06:42:51 -07002212 unsigned long __maybe_unused gp_seq = 0;
Paul E. McKenneyad0dc7f2014-02-19 10:51:42 -08002213
2214 rcutorture_get_gp_data(cur_ops->ttype,
Paul E. McKenneyaebc8262018-05-01 06:42:51 -07002215 &flags, &gp_seq);
Paul E. McKenney7f6733c2017-04-18 17:17:35 -07002216 srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp,
Paul E. McKenneyaebc8262018-05-01 06:42:51 -07002217 &flags, &gp_seq);
Paul E. McKenney4ffa6692016-06-30 11:56:38 -07002218 wtp = READ_ONCE(writer_task);
Peter Zijlstra2f064a52021-06-11 10:28:17 +02002219 pr_alert("??? Writer stall state %s(%d) g%lu f%#x ->state %#x cpu %d\n",
Paul E. McKenney18aff332015-11-17 13:35:28 -08002220 rcu_torture_writer_state_getname(),
Paul E. McKenneyaebc8262018-05-01 06:42:51 -07002221 rcu_torture_writer_state, gp_seq, flags,
Peter Zijlstra2f064a52021-06-11 10:28:17 +02002222 wtp == NULL ? ~0U : wtp->__state,
Paul E. McKenney808de392017-06-19 10:03:22 -07002223 wtp == NULL ? -1 : (int)task_cpu(wtp));
Paul E. McKenney0032f4e2017-08-30 10:40:17 -07002224 if (!splatted && wtp) {
2225 sched_show_task(wtp);
2226 splatted = true;
2227 }
Paul E. McKenney27c0f142020-09-15 17:08:03 -07002228 if (cur_ops->gp_kthread_dbg)
2229 cur_ops->gp_kthread_dbg();
Paul E. McKenney274529b2016-03-21 19:46:04 -07002230 rcu_ftrace_dump(DUMP_ALL);
Paul E. McKenneyad0dc7f2014-02-19 10:51:42 -08002231 }
2232 rtcv_snap = rcu_torture_current_version;
Paul E. McKenneya241ec62005-10-30 15:03:12 -08002233}
2234
2235/*
Paul E. McKenneya241ec62005-10-30 15:03:12 -08002236 * Periodically prints torture statistics, if periodic statistics printing
2237 * was specified via the stat_interval module parameter.
Paul E. McKenneya241ec62005-10-30 15:03:12 -08002238 */
2239static int
2240rcu_torture_stats(void *arg)
2241{
Paul E. McKenney5ccf60f2014-01-29 07:25:25 -08002242 VERBOSE_TOROUT_STRING("rcu_torture_stats task started");
Paul E. McKenneya241ec62005-10-30 15:03:12 -08002243 do {
2244 schedule_timeout_interruptible(stat_interval * HZ);
2245 rcu_torture_stats_print();
Paul E. McKenneyf67a3352014-01-29 07:40:27 -08002246 torture_shutdown_absorb("rcu_torture_stats");
Paul E. McKenney36970bb2014-01-30 15:49:29 -08002247 } while (!torture_must_stop());
Paul E. McKenney7fafaac2014-01-31 17:37:28 -08002248 torture_kthread_stopping("rcu_torture_stats");
Paul E. McKenneya241ec62005-10-30 15:03:12 -08002249 return 0;
2250}
2251
Paul E. McKenney7ab2bd32021-05-02 19:56:05 -07002252/* Test mem_dump_obj() and friends. */
2253static void rcu_torture_mem_dump_obj(void)
2254{
2255 struct rcu_head *rhp;
2256 struct kmem_cache *kcp;
2257 static int z;
2258
2259 kcp = kmem_cache_create("rcuscale", 136, 8, SLAB_STORE_USER, NULL);
Li Qiong1a5ca5e2022-06-12 14:48:25 +08002260 if (WARN_ON_ONCE(!kcp))
2261 return;
Paul E. McKenney7ab2bd32021-05-02 19:56:05 -07002262 rhp = kmem_cache_alloc(kcp, GFP_KERNEL);
Li Qiong1a5ca5e2022-06-12 14:48:25 +08002263 if (WARN_ON_ONCE(!rhp)) {
2264 kmem_cache_destroy(kcp);
2265 return;
2266 }
Paul E. McKenney7ab2bd32021-05-02 19:56:05 -07002267 pr_alert("mem_dump_obj() slab test: rcu_torture_stats = %px, &rhp = %px, rhp = %px, &z = %px\n", stats_task, &rhp, rhp, &z);
2268 pr_alert("mem_dump_obj(ZERO_SIZE_PTR):");
2269 mem_dump_obj(ZERO_SIZE_PTR);
2270 pr_alert("mem_dump_obj(NULL):");
2271 mem_dump_obj(NULL);
2272 pr_alert("mem_dump_obj(%px):", &rhp);
2273 mem_dump_obj(&rhp);
2274 pr_alert("mem_dump_obj(%px):", rhp);
2275 mem_dump_obj(rhp);
2276 pr_alert("mem_dump_obj(%px):", &rhp->func);
2277 mem_dump_obj(&rhp->func);
2278 pr_alert("mem_dump_obj(%px):", &z);
2279 mem_dump_obj(&z);
2280 kmem_cache_free(kcp, rhp);
2281 kmem_cache_destroy(kcp);
2282 rhp = kmalloc(sizeof(*rhp), GFP_KERNEL);
Li Qiong1a5ca5e2022-06-12 14:48:25 +08002283 if (WARN_ON_ONCE(!rhp))
2284 return;
Paul E. McKenney7ab2bd32021-05-02 19:56:05 -07002285 pr_alert("mem_dump_obj() kmalloc test: rcu_torture_stats = %px, &rhp = %px, rhp = %px\n", stats_task, &rhp, rhp);
2286 pr_alert("mem_dump_obj(kmalloc %px):", rhp);
2287 mem_dump_obj(rhp);
2288 pr_alert("mem_dump_obj(kmalloc %px):", &rhp->func);
2289 mem_dump_obj(&rhp->func);
2290 kfree(rhp);
2291 rhp = vmalloc(4096);
Li Qiong1a5ca5e2022-06-12 14:48:25 +08002292 if (WARN_ON_ONCE(!rhp))
2293 return;
Paul E. McKenney7ab2bd32021-05-02 19:56:05 -07002294 pr_alert("mem_dump_obj() vmalloc test: rcu_torture_stats = %px, &rhp = %px, rhp = %px\n", stats_task, &rhp, rhp);
2295 pr_alert("mem_dump_obj(vmalloc %px):", rhp);
2296 mem_dump_obj(rhp);
2297 pr_alert("mem_dump_obj(vmalloc %px):", &rhp->func);
2298 mem_dump_obj(&rhp->func);
2299 vfree(rhp);
2300}
2301
Paul E. McKenneyeac45e52018-05-17 11:33:17 -07002302static void
Steven Rostedt (Red Hat)e66c33d2013-07-12 16:50:28 -04002303rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag)
Paul E. McKenney95c38322006-03-24 03:15:58 -08002304{
Paul E. McKenney2caa1e42012-08-09 16:30:45 -07002305 pr_alert("%s" TORTURE_FLAG
2306 "--- %s: nreaders=%d nfakewriters=%d "
2307 "stat_interval=%d verbose=%d test_no_idle_hz=%d "
2308 "shuffle_interval=%d stutter=%d irqreader=%d "
2309 "fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d "
2310 "test_boost=%d/%d test_boost_interval=%d "
2311 "test_boost_duration=%d shutdown_secs=%d "
Paul E. McKenney2b1516e2017-08-18 16:11:37 -07002312 "stall_cpu=%d stall_cpu_holdoff=%d stall_cpu_irqsoff=%d "
Paul E. McKenney19a8ff92020-03-11 17:39:12 -07002313 "stall_cpu_block=%d "
Paul E. McKenney67afeed2012-10-20 12:56:06 -07002314 "n_barrier_cbs=%d "
Paul E. McKenney4a5f1332020-04-24 11:21:40 -07002315 "onoff_interval=%d onoff_holdoff=%d "
Paul E. McKenney2c4319b2020-09-23 17:39:46 -07002316 "read_exit_delay=%d read_exit_burst=%d "
2317 "nocbs_nthreads=%d nocbs_toggle=%d\n",
Paul E. McKenney2caa1e42012-08-09 16:30:45 -07002318 torture_type, tag, nrealreaders, nfakewriters,
2319 stat_interval, verbose, test_no_idle_hz, shuffle_interval,
2320 stutter, irqreader, fqs_duration, fqs_holdoff, fqs_stutter,
2321 test_boost, cur_ops->can_boost,
2322 test_boost_interval, test_boost_duration, shutdown_secs,
Paul E. McKenney2b1516e2017-08-18 16:11:37 -07002323 stall_cpu, stall_cpu_holdoff, stall_cpu_irqsoff,
Paul E. McKenney19a8ff92020-03-11 17:39:12 -07002324 stall_cpu_block,
Paul E. McKenney67afeed2012-10-20 12:56:06 -07002325 n_barrier_cbs,
Paul E. McKenney4a5f1332020-04-24 11:21:40 -07002326 onoff_interval, onoff_holdoff,
Paul E. McKenney2c4319b2020-09-23 17:39:46 -07002327 read_exit_delay, read_exit_burst,
2328 nocbs_nthreads, nocbs_toggle);
Paul E. McKenney95c38322006-03-24 03:15:58 -08002329}
2330
Sebastian Andrzej Siewior0ffd3742016-08-18 14:57:22 +02002331static int rcutorture_booster_cleanup(unsigned int cpu)
Paul E. McKenney8e8be452010-09-02 16:16:14 -07002332{
2333 struct task_struct *t;
2334
2335 if (boost_tasks[cpu] == NULL)
Sebastian Andrzej Siewior0ffd3742016-08-18 14:57:22 +02002336 return 0;
Paul E. McKenney8e8be452010-09-02 16:16:14 -07002337 mutex_lock(&boost_mutex);
Paul E. McKenney8e8be452010-09-02 16:16:14 -07002338 t = boost_tasks[cpu];
2339 boost_tasks[cpu] = NULL;
Joel Fernandes (Google)450efca2018-06-10 16:45:43 -07002340 rcu_torture_enable_rt_throttle();
Paul E. McKenney8e8be452010-09-02 16:16:14 -07002341 mutex_unlock(&boost_mutex);
2342
2343 /* This must be outside of the mutex, otherwise deadlock! */
Paul E. McKenney9c029b82014-02-04 11:47:08 -08002344 torture_stop_kthread(rcu_torture_boost, t);
Sebastian Andrzej Siewior0ffd3742016-08-18 14:57:22 +02002345 return 0;
Paul E. McKenney8e8be452010-09-02 16:16:14 -07002346}
2347
Sebastian Andrzej Siewior0ffd3742016-08-18 14:57:22 +02002348static int rcutorture_booster_init(unsigned int cpu)
Paul E. McKenney8e8be452010-09-02 16:16:14 -07002349{
2350 int retval;
2351
2352 if (boost_tasks[cpu] != NULL)
2353 return 0; /* Already created, nothing more to do. */
2354
Frederic Weisbecker30021532022-06-10 15:03:57 +02002355 // Testing RCU priority boosting requires rcutorture do
2356 // some serious abuse. Counter this by running ksoftirqd
2357 // at higher priority.
2358 if (IS_BUILTIN(CONFIG_RCU_TORTURE_TEST)) {
2359 struct sched_param sp;
2360 struct task_struct *t;
2361
2362 t = per_cpu(ksoftirqd, cpu);
2363 WARN_ON_ONCE(!t);
2364 sp.sched_priority = 2;
2365 sched_setscheduler_nocheck(t, SCHED_FIFO, &sp);
2366 }
2367
Paul E. McKenney8e8be452010-09-02 16:16:14 -07002368 /* Don't allow time recalculation while creating a new task. */
2369 mutex_lock(&boost_mutex);
Joel Fernandes (Google)450efca2018-06-10 16:45:43 -07002370 rcu_torture_disable_rt_throttle();
Paul E. McKenney5ccf60f2014-01-29 07:25:25 -08002371 VERBOSE_TOROUT_STRING("Creating rcu_torture_boost task");
Cai Huoqing3b9cb4b2022-01-14 14:03:02 -08002372 boost_tasks[cpu] = kthread_run_on_cpu(rcu_torture_boost, NULL,
2373 cpu, "rcu_torture_boost_%u");
Paul E. McKenney8e8be452010-09-02 16:16:14 -07002374 if (IS_ERR(boost_tasks[cpu])) {
2375 retval = PTR_ERR(boost_tasks[cpu]);
Paul E. McKenney5ccf60f2014-01-29 07:25:25 -08002376 VERBOSE_TOROUT_STRING("rcu_torture_boost task create failed");
Paul E. McKenney8e8be452010-09-02 16:16:14 -07002377 n_rcu_torture_boost_ktrerror++;
2378 boost_tasks[cpu] = NULL;
2379 mutex_unlock(&boost_mutex);
2380 return retval;
2381 }
Paul E. McKenney8e8be452010-09-02 16:16:14 -07002382 mutex_unlock(&boost_mutex);
2383 return 0;
2384}
2385
Paul E. McKenneyd5f546d2011-11-04 11:44:12 -07002386/*
Paul E. McKenneyc13f3752012-01-20 15:36:33 -08002387 * CPU-stall kthread. It waits as specified by stall_cpu_holdoff, then
2388 * induces a CPU stall for the time specified by stall_cpu.
2389 */
Paul Gortmaker49fb4c62013-06-19 14:52:21 -04002390static int rcu_torture_stall(void *args)
Paul E. McKenneyc13f3752012-01-20 15:36:33 -08002391{
Paul E. McKenney19a8ff92020-03-11 17:39:12 -07002392 int idx;
Paul E. McKenneyc13f3752012-01-20 15:36:33 -08002393 unsigned long stop_at;
2394
Paul E. McKenney5ccf60f2014-01-29 07:25:25 -08002395 VERBOSE_TOROUT_STRING("rcu_torture_stall task started");
Paul E. McKenneyc13f3752012-01-20 15:36:33 -08002396 if (stall_cpu_holdoff > 0) {
Paul E. McKenney5ccf60f2014-01-29 07:25:25 -08002397 VERBOSE_TOROUT_STRING("rcu_torture_stall begin holdoff");
Paul E. McKenneyc13f3752012-01-20 15:36:33 -08002398 schedule_timeout_interruptible(stall_cpu_holdoff * HZ);
Paul E. McKenney5ccf60f2014-01-29 07:25:25 -08002399 VERBOSE_TOROUT_STRING("rcu_torture_stall end holdoff");
Paul E. McKenneyc13f3752012-01-20 15:36:33 -08002400 }
Paul E. McKenney55b2dcf2020-04-01 19:57:52 -07002401 if (!kthread_should_stop() && stall_gp_kthread > 0) {
2402 VERBOSE_TOROUT_STRING("rcu_torture_stall begin GP stall");
2403 rcu_gp_set_torture_wait(stall_gp_kthread * HZ);
2404 for (idx = 0; idx < stall_gp_kthread + 2; idx++) {
2405 if (kthread_should_stop())
2406 break;
2407 schedule_timeout_uninterruptible(HZ);
2408 }
2409 }
2410 if (!kthread_should_stop() && stall_cpu > 0) {
2411 VERBOSE_TOROUT_STRING("rcu_torture_stall begin CPU stall");
Arnd Bergmann622be33f2018-06-18 16:47:34 +02002412 stop_at = ktime_get_seconds() + stall_cpu;
Paul E. McKenneyc13f3752012-01-20 15:36:33 -08002413 /* RCU CPU stall is expected behavior in following code. */
Paul E. McKenney19a8ff92020-03-11 17:39:12 -07002414 idx = cur_ops->readlock();
Paul E. McKenney2b1516e2017-08-18 16:11:37 -07002415 if (stall_cpu_irqsoff)
2416 local_irq_disable();
Paul E. McKenney19a8ff92020-03-11 17:39:12 -07002417 else if (!stall_cpu_block)
Paul E. McKenney2b1516e2017-08-18 16:11:37 -07002418 preempt_disable();
Stephen Zhang0a27fff2021-01-23 17:54:17 +08002419 pr_alert("%s start on CPU %d.\n",
2420 __func__, raw_smp_processor_id());
Arnd Bergmann622be33f2018-06-18 16:47:34 +02002421 while (ULONG_CMP_LT((unsigned long)ktime_get_seconds(),
2422 stop_at))
Paul E. McKenney59e83662021-05-16 21:17:27 -07002423 if (stall_cpu_block) {
2424#ifdef CONFIG_PREEMPTION
2425 preempt_schedule();
2426#else
Paul E. McKenney19a8ff92020-03-11 17:39:12 -07002427 schedule_timeout_uninterruptible(HZ);
Paul E. McKenney59e83662021-05-16 21:17:27 -07002428#endif
Wander Lairson Costa5ff7c9f2021-11-10 11:37:45 -03002429 } else if (stall_no_softlockup) {
2430 touch_softlockup_watchdog();
Paul E. McKenney59e83662021-05-16 21:17:27 -07002431 }
Paul E. McKenney2b1516e2017-08-18 16:11:37 -07002432 if (stall_cpu_irqsoff)
2433 local_irq_enable();
Paul E. McKenney19a8ff92020-03-11 17:39:12 -07002434 else if (!stall_cpu_block)
Paul E. McKenney2b1516e2017-08-18 16:11:37 -07002435 preempt_enable();
Paul E. McKenney19a8ff92020-03-11 17:39:12 -07002436 cur_ops->readunlock(idx);
Paul E. McKenneyc13f3752012-01-20 15:36:33 -08002437 }
Stephen Zhang0a27fff2021-01-23 17:54:17 +08002438 pr_alert("%s end.\n", __func__);
Paul E. McKenneyf67a3352014-01-29 07:40:27 -08002439 torture_shutdown_absorb("rcu_torture_stall");
Paul E. McKenneyc13f3752012-01-20 15:36:33 -08002440 while (!kthread_should_stop())
2441 schedule_timeout_interruptible(10 * HZ);
2442 return 0;
2443}
2444
2445/* Spawn CPU-stall kthread, if stall_cpu specified. */
2446static int __init rcu_torture_stall_init(void)
2447{
Paul E. McKenney55b2dcf2020-04-01 19:57:52 -07002448 if (stall_cpu <= 0 && stall_gp_kthread <= 0)
Paul E. McKenneyc13f3752012-01-20 15:36:33 -08002449 return 0;
Paul E. McKenney47cf29b2014-02-03 11:52:27 -08002450 return torture_create_kthread(rcu_torture_stall, NULL, stall_task);
Paul E. McKenneyc13f3752012-01-20 15:36:33 -08002451}
2452
Paul E. McKenney9fdcb9a2018-07-19 13:36:00 -07002453/* State structure for forward-progress self-propagating RCU callback. */
2454struct fwd_cb_state {
2455 struct rcu_head rh;
2456 int stop;
2457};
2458
2459/*
2460 * Forward-progress self-propagating RCU callback function. Because
2461 * callbacks run from softirq, this function is an implicit RCU read-side
2462 * critical section.
2463 */
2464static void rcu_torture_fwd_prog_cb(struct rcu_head *rhp)
2465{
2466 struct fwd_cb_state *fcsp = container_of(rhp, struct fwd_cb_state, rh);
2467
2468 if (READ_ONCE(fcsp->stop)) {
2469 WRITE_ONCE(fcsp->stop, 2);
2470 return;
2471 }
2472 cur_ops->call(&fcsp->rh, rcu_torture_fwd_prog_cb);
2473}
2474
Paul E. McKenney48718482018-08-15 15:32:51 -07002475/* State for continuous-flood RCU callbacks. */
2476struct rcu_fwd_cb {
2477 struct rcu_head rh;
2478 struct rcu_fwd_cb *rfc_next;
Paul E. McKenney6b1b8322019-11-05 09:08:58 -08002479 struct rcu_fwd *rfc_rfp;
Paul E. McKenney48718482018-08-15 15:32:51 -07002480 int rfc_gps;
2481};
Paul E. McKenneya289e602019-11-05 08:31:56 -08002482
Paul E. McKenney48718482018-08-15 15:32:51 -07002483#define MAX_FWD_CB_JIFFIES (8 * HZ) /* Maximum CB test duration. */
2484#define MIN_FWD_CB_LAUNDERS 3 /* This many CB invocations to count. */
2485#define MIN_FWD_CBS_LAUNDERED 100 /* Number of counted CBs. */
Paul E. McKenney2e57bf92018-10-05 16:43:09 -07002486#define FWD_CBS_HIST_DIV 10 /* Histogram buckets/second. */
Paul E. McKenneya289e602019-11-05 08:31:56 -08002487#define N_LAUNDERS_HIST (2 * MAX_FWD_CB_JIFFIES / (HZ / FWD_CBS_HIST_DIV))
2488
Paul E. McKenneycd618d12019-01-08 13:41:26 -08002489struct rcu_launder_hist {
2490 long n_launders;
2491 unsigned long launder_gp_seq;
2492};
Paul E. McKenney48718482018-08-15 15:32:51 -07002493
Paul E. McKenneya289e602019-11-05 08:31:56 -08002494struct rcu_fwd {
2495 spinlock_t rcu_fwd_lock;
2496 struct rcu_fwd_cb *rcu_fwd_cb_head;
2497 struct rcu_fwd_cb **rcu_fwd_cb_tail;
2498 long n_launders_cb;
2499 unsigned long rcu_fwd_startat;
2500 struct rcu_launder_hist n_launders_hist[N_LAUNDERS_HIST];
2501 unsigned long rcu_launder_gp_seq_start;
Paul E. McKenney82e31002021-11-22 20:55:18 -08002502 int rcu_fwd_id;
Paul E. McKenneya289e602019-11-05 08:31:56 -08002503};
2504
Paul E. McKenney57f60202020-07-20 08:34:07 -07002505static DEFINE_MUTEX(rcu_fwd_mutex);
Jason Yanafbc1572020-04-09 19:42:38 +08002506static struct rcu_fwd *rcu_fwds;
Paul E. McKenney82e31002021-11-22 20:55:18 -08002507static unsigned long rcu_fwd_seq;
Paul E. McKenney53b541f2021-11-23 13:51:11 -08002508static atomic_long_t rcu_fwd_max_cbs;
Jason Yanafbc1572020-04-09 19:42:38 +08002509static bool rcu_fwd_emergency_stop;
Paul E. McKenney48718482018-08-15 15:32:51 -07002510
Paul E. McKenney6b1b8322019-11-05 09:08:58 -08002511static void rcu_torture_fwd_cb_hist(struct rcu_fwd *rfp)
Paul E. McKenney1a682752018-10-03 12:33:41 -07002512{
Paul E. McKenneycd618d12019-01-08 13:41:26 -08002513 unsigned long gps;
2514 unsigned long gps_old;
Paul E. McKenney1a682752018-10-03 12:33:41 -07002515 int i;
2516 int j;
2517
Paul E. McKenney6b1b8322019-11-05 09:08:58 -08002518 for (i = ARRAY_SIZE(rfp->n_launders_hist) - 1; i > 0; i--)
2519 if (rfp->n_launders_hist[i].n_launders > 0)
Paul E. McKenney1a682752018-10-03 12:33:41 -07002520 break;
Paul E. McKenney82e31002021-11-22 20:55:18 -08002521 pr_alert("%s: Callback-invocation histogram %d (duration %lu jiffies):",
2522 __func__, rfp->rcu_fwd_id, jiffies - rfp->rcu_fwd_startat);
Paul E. McKenney6b1b8322019-11-05 09:08:58 -08002523 gps_old = rfp->rcu_launder_gp_seq_start;
Paul E. McKenneycd618d12019-01-08 13:41:26 -08002524 for (j = 0; j <= i; j++) {
Paul E. McKenney6b1b8322019-11-05 09:08:58 -08002525 gps = rfp->n_launders_hist[j].launder_gp_seq;
Paul E. McKenneycd618d12019-01-08 13:41:26 -08002526 pr_cont(" %ds/%d: %ld:%ld",
Paul E. McKenneya289e602019-11-05 08:31:56 -08002527 j + 1, FWD_CBS_HIST_DIV,
Paul E. McKenney6b1b8322019-11-05 09:08:58 -08002528 rfp->n_launders_hist[j].n_launders,
Paul E. McKenneycd618d12019-01-08 13:41:26 -08002529 rcutorture_seq_diff(gps, gps_old));
2530 gps_old = gps;
2531 }
Paul E. McKenney1a682752018-10-03 12:33:41 -07002532 pr_cont("\n");
2533}
2534
Paul E. McKenney48718482018-08-15 15:32:51 -07002535/* Callback function for continuous-flood RCU callbacks. */
2536static void rcu_torture_fwd_cb_cr(struct rcu_head *rhp)
2537{
Paul E. McKenney2667ccc2018-10-05 09:09:49 -07002538 unsigned long flags;
Paul E. McKenney48718482018-08-15 15:32:51 -07002539 int i;
2540 struct rcu_fwd_cb *rfcp = container_of(rhp, struct rcu_fwd_cb, rh);
2541 struct rcu_fwd_cb **rfcpp;
Paul E. McKenney6b1b8322019-11-05 09:08:58 -08002542 struct rcu_fwd *rfp = rfcp->rfc_rfp;
Paul E. McKenney48718482018-08-15 15:32:51 -07002543
2544 rfcp->rfc_next = NULL;
2545 rfcp->rfc_gps++;
Paul E. McKenney6b1b8322019-11-05 09:08:58 -08002546 spin_lock_irqsave(&rfp->rcu_fwd_lock, flags);
2547 rfcpp = rfp->rcu_fwd_cb_tail;
2548 rfp->rcu_fwd_cb_tail = &rfcp->rfc_next;
Paul E. McKenney48718482018-08-15 15:32:51 -07002549 WRITE_ONCE(*rfcpp, rfcp);
Paul E. McKenney6b1b8322019-11-05 09:08:58 -08002550 WRITE_ONCE(rfp->n_launders_cb, rfp->n_launders_cb + 1);
2551 i = ((jiffies - rfp->rcu_fwd_startat) / (HZ / FWD_CBS_HIST_DIV));
2552 if (i >= ARRAY_SIZE(rfp->n_launders_hist))
2553 i = ARRAY_SIZE(rfp->n_launders_hist) - 1;
2554 rfp->n_launders_hist[i].n_launders++;
2555 rfp->n_launders_hist[i].launder_gp_seq = cur_ops->get_gp_seq();
2556 spin_unlock_irqrestore(&rfp->rcu_fwd_lock, flags);
Paul E. McKenney2667ccc2018-10-05 09:09:49 -07002557}
2558
Paul E. McKenneyab21f602019-04-14 18:30:22 -07002559// Give the scheduler a chance, even on nohz_full CPUs.
Paul E. McKenneybd1bfc52019-06-22 14:35:59 -07002560static void rcu_torture_fwd_prog_cond_resched(unsigned long iter)
Paul E. McKenneyab21f602019-04-14 18:30:22 -07002561{
Sebastian Andrzej Siewior90326f02019-10-15 21:18:14 +02002562 if (IS_ENABLED(CONFIG_PREEMPTION) && IS_ENABLED(CONFIG_NO_HZ_FULL)) {
Paul E. McKenneybd1bfc52019-06-22 14:35:59 -07002563 // Real call_rcu() floods hit userspace, so emulate that.
2564 if (need_resched() || (iter & 0xfff))
Paul E. McKenneyab21f602019-04-14 18:30:22 -07002565 schedule();
Paul E. McKenneyd38e6dc2019-07-28 12:00:48 -07002566 return;
Paul E. McKenneyab21f602019-04-14 18:30:22 -07002567 }
Paul E. McKenneyd38e6dc2019-07-28 12:00:48 -07002568 // No userspace emulation: CB invocation throttles call_rcu()
2569 cond_resched();
Paul E. McKenneyab21f602019-04-14 18:30:22 -07002570}
2571
Paul E. McKenney2667ccc2018-10-05 09:09:49 -07002572/*
2573 * Free all callbacks on the rcu_fwd_cb_head list, either because the
2574 * test is over or because we hit an OOM event.
2575 */
Paul E. McKenney67641002019-11-06 08:20:20 -08002576static unsigned long rcu_torture_fwd_prog_cbfree(struct rcu_fwd *rfp)
Paul E. McKenney2667ccc2018-10-05 09:09:49 -07002577{
2578 unsigned long flags;
2579 unsigned long freed = 0;
2580 struct rcu_fwd_cb *rfcp;
2581
2582 for (;;) {
Paul E. McKenney67641002019-11-06 08:20:20 -08002583 spin_lock_irqsave(&rfp->rcu_fwd_lock, flags);
2584 rfcp = rfp->rcu_fwd_cb_head;
Paul E. McKenney140e53f2019-04-09 10:08:18 -07002585 if (!rfcp) {
Paul E. McKenney67641002019-11-06 08:20:20 -08002586 spin_unlock_irqrestore(&rfp->rcu_fwd_lock, flags);
Paul E. McKenney2667ccc2018-10-05 09:09:49 -07002587 break;
Paul E. McKenney140e53f2019-04-09 10:08:18 -07002588 }
Paul E. McKenney67641002019-11-06 08:20:20 -08002589 rfp->rcu_fwd_cb_head = rfcp->rfc_next;
2590 if (!rfp->rcu_fwd_cb_head)
2591 rfp->rcu_fwd_cb_tail = &rfp->rcu_fwd_cb_head;
2592 spin_unlock_irqrestore(&rfp->rcu_fwd_lock, flags);
Paul E. McKenney2667ccc2018-10-05 09:09:49 -07002593 kfree(rfcp);
2594 freed++;
Paul E. McKenneybd1bfc52019-06-22 14:35:59 -07002595 rcu_torture_fwd_prog_cond_resched(freed);
Paul E. McKenney79ba7ff2019-08-04 13:17:35 -07002596 if (tick_nohz_full_enabled()) {
2597 local_irq_save(flags);
2598 rcu_momentary_dyntick_idle();
2599 local_irq_restore(flags);
2600 }
Paul E. McKenney2667ccc2018-10-05 09:09:49 -07002601 }
Paul E. McKenney2667ccc2018-10-05 09:09:49 -07002602 return freed;
Paul E. McKenney48718482018-08-15 15:32:51 -07002603}
2604
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002605/* Carry out need_resched()/cond_resched() forward-progress testing. */
Paul E. McKenney6b1b8322019-11-05 09:08:58 -08002606static void rcu_torture_fwd_prog_nr(struct rcu_fwd *rfp,
2607 int *tested, int *tested_tries)
Paul E. McKenney1b272912018-07-18 14:32:31 -07002608{
Paul E. McKenney119248b2018-07-18 15:39:37 -07002609 unsigned long cver;
Paul E. McKenneyf4de46e2018-07-24 20:50:40 -07002610 unsigned long dur;
Paul E. McKenney7c590fc2018-08-07 16:42:42 -07002611 struct fwd_cb_state fcs;
Paul E. McKenney119248b2018-07-18 15:39:37 -07002612 unsigned long gps;
Paul E. McKenney1b272912018-07-18 14:32:31 -07002613 int idx;
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002614 int sd;
2615 int sd4;
2616 bool selfpropcb = false;
2617 unsigned long stopat;
2618 static DEFINE_TORTURE_RANDOM(trs);
2619
Paul E. McKenney05b72462021-12-16 15:36:02 -08002620 pr_alert("%s: Starting forward-progress test %d\n", __func__, rfp->rcu_fwd_id);
Paul E. McKenneya7eb9372020-10-09 19:51:55 -07002621 if (!cur_ops->sync)
2622 return; // Cannot do need_resched() forward progress testing without ->sync.
2623 if (cur_ops->call && cur_ops->cb_barrier) {
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002624 init_rcu_head_on_stack(&fcs.rh);
2625 selfpropcb = true;
2626 }
2627
2628 /* Tight loop containing cond_resched(). */
Paul E. McKenneye22ef8d2021-12-17 12:33:53 -08002629 atomic_inc(&rcu_fwd_cb_nodelay);
Paul E. McKenneye8516c62019-04-09 11:06:32 -07002630 cur_ops->sync(); /* Later readers see above write. */
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002631 if (selfpropcb) {
2632 WRITE_ONCE(fcs.stop, 0);
2633 cur_ops->call(&fcs.rh, rcu_torture_fwd_prog_cb);
2634 }
2635 cver = READ_ONCE(rcu_torture_current_version);
2636 gps = cur_ops->get_gp_seq();
2637 sd = cur_ops->stall_dur() + 1;
2638 sd4 = (sd + fwd_progress_div - 1) / fwd_progress_div;
2639 dur = sd4 + torture_random(&trs) % (sd - sd4);
Paul E. McKenney6b1b8322019-11-05 09:08:58 -08002640 WRITE_ONCE(rfp->rcu_fwd_startat, jiffies);
2641 stopat = rfp->rcu_fwd_startat + dur;
Paul E. McKenneye0aff972018-10-01 17:40:54 -07002642 while (time_before(jiffies, stopat) &&
Paul E. McKenney60013d52019-07-10 08:30:00 -07002643 !shutdown_time_arrived() &&
Paul E. McKenneye0aff972018-10-01 17:40:54 -07002644 !READ_ONCE(rcu_fwd_emergency_stop) && !torture_must_stop()) {
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002645 idx = cur_ops->readlock();
2646 udelay(10);
2647 cur_ops->readunlock(idx);
2648 if (!fwd_progress_need_resched || need_resched())
Paul E. McKenneyfbbd5e32019-08-15 11:43:53 -07002649 cond_resched();
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002650 }
2651 (*tested_tries)++;
Paul E. McKenneye0aff972018-10-01 17:40:54 -07002652 if (!time_before(jiffies, stopat) &&
Paul E. McKenney60013d52019-07-10 08:30:00 -07002653 !shutdown_time_arrived() &&
Paul E. McKenneye0aff972018-10-01 17:40:54 -07002654 !READ_ONCE(rcu_fwd_emergency_stop) && !torture_must_stop()) {
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002655 (*tested)++;
2656 cver = READ_ONCE(rcu_torture_current_version) - cver;
2657 gps = rcutorture_seq_diff(cur_ops->get_gp_seq(), gps);
2658 WARN_ON(!cver && gps < 2);
Paul E. McKenney82e31002021-11-22 20:55:18 -08002659 pr_alert("%s: %d Duration %ld cver %ld gps %ld\n", __func__,
2660 rfp->rcu_fwd_id, dur, cver, gps);
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002661 }
2662 if (selfpropcb) {
2663 WRITE_ONCE(fcs.stop, 1);
2664 cur_ops->sync(); /* Wait for running CB to complete. */
Paul E. McKenney05b72462021-12-16 15:36:02 -08002665 pr_alert("%s: Waiting for CBs: %pS() %d\n", __func__, cur_ops->cb_barrier, rfp->rcu_fwd_id);
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002666 cur_ops->cb_barrier(); /* Wait for queued callbacks. */
2667 }
2668
2669 if (selfpropcb) {
2670 WARN_ON(READ_ONCE(fcs.stop) != 2);
2671 destroy_rcu_head_on_stack(&fcs.rh);
2672 }
Paul E. McKenneye8516c62019-04-09 11:06:32 -07002673 schedule_timeout_uninterruptible(HZ / 10); /* Let kthreads recover. */
Paul E. McKenneye22ef8d2021-12-17 12:33:53 -08002674 atomic_dec(&rcu_fwd_cb_nodelay);
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002675}
2676
2677/* Carry out call_rcu() forward-progress testing. */
Paul E. McKenney6b1b8322019-11-05 09:08:58 -08002678static void rcu_torture_fwd_prog_cr(struct rcu_fwd *rfp)
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002679{
2680 unsigned long cver;
Paul E. McKenney79ba7ff2019-08-04 13:17:35 -07002681 unsigned long flags;
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002682 unsigned long gps;
2683 int i;
Paul E. McKenney48718482018-08-15 15:32:51 -07002684 long n_launders;
2685 long n_launders_cb_snap;
2686 long n_launders_sa;
2687 long n_max_cbs;
2688 long n_max_gps;
2689 struct rcu_fwd_cb *rfcp;
2690 struct rcu_fwd_cb *rfcpn;
Paul E. McKenney1b272912018-07-18 14:32:31 -07002691 unsigned long stopat;
Paul E. McKenney48718482018-08-15 15:32:51 -07002692 unsigned long stoppedat;
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002693
Paul E. McKenney05b72462021-12-16 15:36:02 -08002694 pr_alert("%s: Starting forward-progress test %d\n", __func__, rfp->rcu_fwd_id);
Paul E. McKenney2667ccc2018-10-05 09:09:49 -07002695 if (READ_ONCE(rcu_fwd_emergency_stop))
2696 return; /* Get out of the way quickly, no GP wait! */
Paul E. McKenneyc682db52019-04-19 07:38:27 -07002697 if (!cur_ops->call)
2698 return; /* Can't do call_rcu() fwd prog without ->call. */
Paul E. McKenney2667ccc2018-10-05 09:09:49 -07002699
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002700 /* Loop continuously posting RCU callbacks. */
Paul E. McKenneye22ef8d2021-12-17 12:33:53 -08002701 atomic_inc(&rcu_fwd_cb_nodelay);
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002702 cur_ops->sync(); /* Later readers see above write. */
Paul E. McKenney6b1b8322019-11-05 09:08:58 -08002703 WRITE_ONCE(rfp->rcu_fwd_startat, jiffies);
2704 stopat = rfp->rcu_fwd_startat + MAX_FWD_CB_JIFFIES;
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002705 n_launders = 0;
Paul E. McKenney6b1b8322019-11-05 09:08:58 -08002706 rfp->n_launders_cb = 0; // Hoist initialization for multi-kthread
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002707 n_launders_sa = 0;
2708 n_max_cbs = 0;
2709 n_max_gps = 0;
Paul E. McKenney6b1b8322019-11-05 09:08:58 -08002710 for (i = 0; i < ARRAY_SIZE(rfp->n_launders_hist); i++)
2711 rfp->n_launders_hist[i].n_launders = 0;
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002712 cver = READ_ONCE(rcu_torture_current_version);
2713 gps = cur_ops->get_gp_seq();
Paul E. McKenney6b1b8322019-11-05 09:08:58 -08002714 rfp->rcu_launder_gp_seq_start = gps;
Paul E. McKenneyd38e6dc2019-07-28 12:00:48 -07002715 tick_dep_set_task(current, TICK_DEP_BIT_RCU);
Paul E. McKenneye0aff972018-10-01 17:40:54 -07002716 while (time_before(jiffies, stopat) &&
Paul E. McKenney60013d52019-07-10 08:30:00 -07002717 !shutdown_time_arrived() &&
Paul E. McKenneye0aff972018-10-01 17:40:54 -07002718 !READ_ONCE(rcu_fwd_emergency_stop) && !torture_must_stop()) {
Paul E. McKenney6b1b8322019-11-05 09:08:58 -08002719 rfcp = READ_ONCE(rfp->rcu_fwd_cb_head);
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002720 rfcpn = NULL;
2721 if (rfcp)
2722 rfcpn = READ_ONCE(rfcp->rfc_next);
2723 if (rfcpn) {
2724 if (rfcp->rfc_gps >= MIN_FWD_CB_LAUNDERS &&
2725 ++n_max_gps >= MIN_FWD_CBS_LAUNDERED)
2726 break;
Paul E. McKenney6b1b8322019-11-05 09:08:58 -08002727 rfp->rcu_fwd_cb_head = rfcpn;
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002728 n_launders++;
2729 n_launders_sa++;
Paul E. McKenney613b00f2021-11-23 11:53:52 -08002730 } else if (!cur_ops->cbflood_max || cur_ops->cbflood_max > n_max_cbs) {
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002731 rfcp = kmalloc(sizeof(*rfcp), GFP_KERNEL);
2732 if (WARN_ON_ONCE(!rfcp)) {
2733 schedule_timeout_interruptible(1);
2734 continue;
2735 }
2736 n_max_cbs++;
2737 n_launders_sa = 0;
2738 rfcp->rfc_gps = 0;
Paul E. McKenney6b1b8322019-11-05 09:08:58 -08002739 rfcp->rfc_rfp = rfp;
Paul E. McKenney613b00f2021-11-23 11:53:52 -08002740 } else {
2741 rfcp = NULL;
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002742 }
Paul E. McKenney613b00f2021-11-23 11:53:52 -08002743 if (rfcp)
2744 cur_ops->call(&rfcp->rh, rcu_torture_fwd_cb_cr);
Paul E. McKenneybd1bfc52019-06-22 14:35:59 -07002745 rcu_torture_fwd_prog_cond_resched(n_launders + n_max_cbs);
Paul E. McKenney79ba7ff2019-08-04 13:17:35 -07002746 if (tick_nohz_full_enabled()) {
2747 local_irq_save(flags);
2748 rcu_momentary_dyntick_idle();
2749 local_irq_restore(flags);
2750 }
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002751 }
2752 stoppedat = jiffies;
Paul E. McKenney6b1b8322019-11-05 09:08:58 -08002753 n_launders_cb_snap = READ_ONCE(rfp->n_launders_cb);
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002754 cver = READ_ONCE(rcu_torture_current_version) - cver;
2755 gps = rcutorture_seq_diff(cur_ops->get_gp_seq(), gps);
Paul E. McKenney05b72462021-12-16 15:36:02 -08002756 pr_alert("%s: Waiting for CBs: %pS() %d\n", __func__, cur_ops->cb_barrier, rfp->rcu_fwd_id);
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002757 cur_ops->cb_barrier(); /* Wait for callbacks to be invoked. */
Paul E. McKenney67641002019-11-06 08:20:20 -08002758 (void)rcu_torture_fwd_prog_cbfree(rfp);
Paul E. McKenney2667ccc2018-10-05 09:09:49 -07002759
Paul E. McKenney60013d52019-07-10 08:30:00 -07002760 if (!torture_must_stop() && !READ_ONCE(rcu_fwd_emergency_stop) &&
2761 !shutdown_time_arrived()) {
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002762 WARN_ON(n_max_gps < MIN_FWD_CBS_LAUNDERED);
2763 pr_alert("%s Duration %lu barrier: %lu pending %ld n_launders: %ld n_launders_sa: %ld n_max_gps: %ld n_max_cbs: %ld cver %ld gps %ld\n",
2764 __func__,
Paul E. McKenney6b1b8322019-11-05 09:08:58 -08002765 stoppedat - rfp->rcu_fwd_startat, jiffies - stoppedat,
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002766 n_launders + n_max_cbs - n_launders_cb_snap,
2767 n_launders, n_launders_sa,
2768 n_max_gps, n_max_cbs, cver, gps);
Paul E. McKenney53b541f2021-11-23 13:51:11 -08002769 atomic_long_add(n_max_cbs, &rcu_fwd_max_cbs);
Paul E. McKenney89440d22021-12-28 15:59:38 -08002770 mutex_lock(&rcu_fwd_mutex); // Serialize histograms.
Paul E. McKenney6b1b8322019-11-05 09:08:58 -08002771 rcu_torture_fwd_cb_hist(rfp);
Paul E. McKenney89440d22021-12-28 15:59:38 -08002772 mutex_unlock(&rcu_fwd_mutex);
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002773 }
Paul E. McKenneye8516c62019-04-09 11:06:32 -07002774 schedule_timeout_uninterruptible(HZ); /* Let CBs drain. */
Paul E. McKenneyd38e6dc2019-07-28 12:00:48 -07002775 tick_dep_clear_task(current, TICK_DEP_BIT_RCU);
Paul E. McKenneye22ef8d2021-12-17 12:33:53 -08002776 atomic_dec(&rcu_fwd_cb_nodelay);
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002777}
2778
Paul E. McKenneye0aff972018-10-01 17:40:54 -07002779
2780/*
2781 * OOM notifier, but this only prints diagnostic information for the
2782 * current forward-progress test.
2783 */
2784static int rcutorture_oom_notify(struct notifier_block *self,
2785 unsigned long notused, void *nfreed)
2786{
Paul E. McKenney82e31002021-11-22 20:55:18 -08002787 int i;
2788 long ncbs;
Paul E. McKenney57f60202020-07-20 08:34:07 -07002789 struct rcu_fwd *rfp;
Paul E. McKenney67641002019-11-06 08:20:20 -08002790
Paul E. McKenney57f60202020-07-20 08:34:07 -07002791 mutex_lock(&rcu_fwd_mutex);
2792 rfp = rcu_fwds;
2793 if (!rfp) {
2794 mutex_unlock(&rcu_fwd_mutex);
2795 return NOTIFY_OK;
2796 }
Paul E. McKenney2667ccc2018-10-05 09:09:49 -07002797 WARN(1, "%s invoked upon OOM during forward-progress testing.\n",
2798 __func__);
Paul E. McKenney82e31002021-11-22 20:55:18 -08002799 for (i = 0; i < fwd_progress; i++) {
2800 rcu_torture_fwd_cb_hist(&rfp[i]);
2801 rcu_fwd_progress_check(1 + (jiffies - READ_ONCE(rfp[i].rcu_fwd_startat)) / 2);
2802 }
Paul E. McKenneye0aff972018-10-01 17:40:54 -07002803 WRITE_ONCE(rcu_fwd_emergency_stop, true);
Paul E. McKenney2667ccc2018-10-05 09:09:49 -07002804 smp_mb(); /* Emergency stop before free and wait to avoid hangs. */
Paul E. McKenney82e31002021-11-22 20:55:18 -08002805 ncbs = 0;
2806 for (i = 0; i < fwd_progress; i++)
2807 ncbs += rcu_torture_fwd_prog_cbfree(&rfp[i]);
2808 pr_info("%s: Freed %lu RCU callbacks.\n", __func__, ncbs);
Zqiang48297a22022-07-31 18:53:56 +08002809 cur_ops->cb_barrier();
Paul E. McKenney82e31002021-11-22 20:55:18 -08002810 ncbs = 0;
2811 for (i = 0; i < fwd_progress; i++)
2812 ncbs += rcu_torture_fwd_prog_cbfree(&rfp[i]);
2813 pr_info("%s: Freed %lu RCU callbacks.\n", __func__, ncbs);
Zqiang48297a22022-07-31 18:53:56 +08002814 cur_ops->cb_barrier();
Paul E. McKenney82e31002021-11-22 20:55:18 -08002815 ncbs = 0;
2816 for (i = 0; i < fwd_progress; i++)
2817 ncbs += rcu_torture_fwd_prog_cbfree(&rfp[i]);
2818 pr_info("%s: Freed %lu RCU callbacks.\n", __func__, ncbs);
Paul E. McKenney2667ccc2018-10-05 09:09:49 -07002819 smp_mb(); /* Frees before return to avoid redoing OOM. */
2820 (*(unsigned long *)nfreed)++; /* Forward progress CBs freed! */
2821 pr_info("%s returning after OOM processing.\n", __func__);
Paul E. McKenney57f60202020-07-20 08:34:07 -07002822 mutex_unlock(&rcu_fwd_mutex);
Paul E. McKenneye0aff972018-10-01 17:40:54 -07002823 return NOTIFY_OK;
2824}
2825
2826static struct notifier_block rcutorture_oom_nb = {
2827 .notifier_call = rcutorture_oom_notify
2828};
2829
Paul E. McKenney6b3de7a2018-08-28 14:38:43 -07002830/* Carry out grace-period forward-progress testing. */
2831static int rcu_torture_fwd_prog(void *args)
2832{
Paul E. McKenney53b541f2021-11-23 13:51:11 -08002833 bool firsttime = true;
2834 long max_cbs;
Paul E. McKenneyab1b7882020-09-22 16:42:42 -07002835 int oldnice = task_nice(current);
Paul E. McKenney82e31002021-11-22 20:55:18 -08002836 unsigned long oldseq = READ_ONCE(rcu_fwd_seq);
Paul E. McKenney6b1b8322019-11-05 09:08:58 -08002837 struct rcu_fwd *rfp = args;
Paul E. McKenneyf4de46e2018-07-24 20:50:40 -07002838 int tested = 0;
Paul E. McKenney152f4af2018-07-19 10:57:58 -07002839 int tested_tries = 0;
Paul E. McKenney1b272912018-07-18 14:32:31 -07002840
2841 VERBOSE_TOROUT_STRING("rcu_torture_fwd_progress task started");
Paul E. McKenney5ab7ab82018-09-21 18:08:09 -07002842 rcu_bind_current_to_nocb();
Paul E. McKenneyfecad502018-07-20 12:18:11 -07002843 if (!IS_ENABLED(CONFIG_SMP) || !IS_ENABLED(CONFIG_RCU_BOOST))
2844 set_user_nice(current, MAX_NICE);
Paul E. McKenney1b272912018-07-18 14:32:31 -07002845 do {
Paul E. McKenney82e31002021-11-22 20:55:18 -08002846 if (!rfp->rcu_fwd_id) {
2847 schedule_timeout_interruptible(fwd_progress_holdoff * HZ);
2848 WRITE_ONCE(rcu_fwd_emergency_stop, false);
Paul E. McKenney53b541f2021-11-23 13:51:11 -08002849 if (!firsttime) {
2850 max_cbs = atomic_long_xchg(&rcu_fwd_max_cbs, 0);
2851 pr_alert("%s n_max_cbs: %ld\n", __func__, max_cbs);
2852 }
2853 firsttime = false;
Paul E. McKenney82e31002021-11-22 20:55:18 -08002854 WRITE_ONCE(rcu_fwd_seq, rcu_fwd_seq + 1);
2855 } else {
Paul E. McKenney02b51a12021-12-17 15:05:05 -08002856 while (READ_ONCE(rcu_fwd_seq) == oldseq && !torture_must_stop())
Paul E. McKenney82e31002021-11-22 20:55:18 -08002857 schedule_timeout_interruptible(1);
2858 oldseq = READ_ONCE(rcu_fwd_seq);
2859 }
2860 pr_alert("%s: Starting forward-progress test %d\n", __func__, rfp->rcu_fwd_id);
2861 if (rcu_inkernel_boot_has_ended() && torture_num_online_cpus() > rfp->rcu_fwd_id)
Paul E. McKenney43550802019-12-04 15:58:41 -08002862 rcu_torture_fwd_prog_cr(rfp);
Paul E. McKenney613b00f2021-11-23 11:53:52 -08002863 if ((cur_ops->stall_dur && cur_ops->stall_dur() > 0) &&
2864 (!IS_ENABLED(CONFIG_TINY_RCU) ||
2865 (rcu_inkernel_boot_has_ended() &&
2866 torture_num_online_cpus() > rfp->rcu_fwd_id)))
Paul E. McKenney82e31002021-11-22 20:55:18 -08002867 rcu_torture_fwd_prog_nr(rfp, &tested, &tested_tries);
Paul E. McKenney48718482018-08-15 15:32:51 -07002868
Paul E. McKenney1b272912018-07-18 14:32:31 -07002869 /* Avoid slow periods, better to test when busy. */
Paul E. McKenneyab1b7882020-09-22 16:42:42 -07002870 if (stutter_wait("rcu_torture_fwd_prog"))
2871 sched_set_normal(current, oldnice);
Paul E. McKenney1b272912018-07-18 14:32:31 -07002872 } while (!torture_must_stop());
Paul E. McKenney152f4af2018-07-19 10:57:58 -07002873 /* Short runs might not contain a valid forward-progress attempt. */
Paul E. McKenney82e31002021-11-22 20:55:18 -08002874 if (!rfp->rcu_fwd_id) {
2875 WARN_ON(!tested && tested_tries >= 5);
2876 pr_alert("%s: tested %d tested_tries %d\n", __func__, tested, tested_tries);
2877 }
Paul E. McKenney1b272912018-07-18 14:32:31 -07002878 torture_kthread_stopping("rcu_torture_fwd_prog");
2879 return 0;
2880}
2881
2882/* If forward-progress checking is requested and feasible, spawn the thread. */
2883static int __init rcu_torture_fwd_prog_init(void)
2884{
Paul E. McKenney82e31002021-11-22 20:55:18 -08002885 int i;
2886 int ret = 0;
Paul E. McKenney5155be92019-11-06 08:35:08 -08002887 struct rcu_fwd *rfp;
Paul E. McKenney67641002019-11-06 08:20:20 -08002888
Paul E. McKenney1b272912018-07-18 14:32:31 -07002889 if (!fwd_progress)
2890 return 0; /* Not requested, so don't do it. */
Paul E. McKenney82e31002021-11-22 20:55:18 -08002891 if (fwd_progress >= nr_cpu_ids) {
2892 VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Limiting fwd_progress to # CPUs.\n");
2893 fwd_progress = nr_cpu_ids;
2894 } else if (fwd_progress < 0) {
2895 fwd_progress = nr_cpu_ids;
2896 }
Paul E. McKenneya7eb9372020-10-09 19:51:55 -07002897 if ((!cur_ops->sync && !cur_ops->call) ||
Paul E. McKenney613b00f2021-11-23 11:53:52 -08002898 (!cur_ops->cbflood_max && (!cur_ops->stall_dur || cur_ops->stall_dur() <= 0)) ||
2899 cur_ops == &rcu_busted_ops) {
Paul E. McKenney1b272912018-07-18 14:32:31 -07002900 VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Disabled, unsupported by RCU flavor under test");
Paul E. McKenney82e31002021-11-22 20:55:18 -08002901 fwd_progress = 0;
Paul E. McKenney1b272912018-07-18 14:32:31 -07002902 return 0;
2903 }
2904 if (stall_cpu > 0) {
2905 VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Disabled, conflicts with CPU-stall testing");
Paul E. McKenney82e31002021-11-22 20:55:18 -08002906 fwd_progress = 0;
Zhouyi Zhou3ac85872021-07-26 05:43:33 +08002907 if (IS_MODULE(CONFIG_RCU_TORTURE_TEST))
Paul E. McKenney1b272912018-07-18 14:32:31 -07002908 return -EINVAL; /* In module, can fail back to user. */
2909 WARN_ON(1); /* Make sure rcutorture notices conflict. */
2910 return 0;
2911 }
2912 if (fwd_progress_holdoff <= 0)
2913 fwd_progress_holdoff = 1;
2914 if (fwd_progress_div <= 0)
2915 fwd_progress_div = 4;
Paul E. McKenney82e31002021-11-22 20:55:18 -08002916 rfp = kcalloc(fwd_progress, sizeof(*rfp), GFP_KERNEL);
2917 fwd_prog_tasks = kcalloc(fwd_progress, sizeof(*fwd_prog_tasks), GFP_KERNEL);
2918 if (!rfp || !fwd_prog_tasks) {
2919 kfree(rfp);
2920 kfree(fwd_prog_tasks);
2921 fwd_prog_tasks = NULL;
2922 fwd_progress = 0;
Paul E. McKenney5155be92019-11-06 08:35:08 -08002923 return -ENOMEM;
Paul E. McKenney82e31002021-11-22 20:55:18 -08002924 }
2925 for (i = 0; i < fwd_progress; i++) {
2926 spin_lock_init(&rfp[i].rcu_fwd_lock);
2927 rfp[i].rcu_fwd_cb_tail = &rfp[i].rcu_fwd_cb_head;
2928 rfp[i].rcu_fwd_id = i;
2929 }
Paul E. McKenney57f60202020-07-20 08:34:07 -07002930 mutex_lock(&rcu_fwd_mutex);
Paul E. McKenneyc8fa6372020-07-19 14:40:31 -07002931 rcu_fwds = rfp;
Paul E. McKenney57f60202020-07-20 08:34:07 -07002932 mutex_unlock(&rcu_fwd_mutex);
Paul E. McKenney299c7d92020-07-22 10:45:12 -07002933 register_oom_notifier(&rcutorture_oom_nb);
Paul E. McKenney82e31002021-11-22 20:55:18 -08002934 for (i = 0; i < fwd_progress; i++) {
2935 ret = torture_create_kthread(rcu_torture_fwd_prog, &rcu_fwds[i], fwd_prog_tasks[i]);
2936 if (ret) {
2937 fwd_progress = i;
2938 return ret;
2939 }
2940 }
2941 return 0;
Paul E. McKenney1b272912018-07-18 14:32:31 -07002942}
2943
Paul E. McKenneyc8fa6372020-07-19 14:40:31 -07002944static void rcu_torture_fwd_prog_cleanup(void)
2945{
Paul E. McKenney82e31002021-11-22 20:55:18 -08002946 int i;
Paul E. McKenneyc8fa6372020-07-19 14:40:31 -07002947 struct rcu_fwd *rfp;
2948
Paul E. McKenney82e31002021-11-22 20:55:18 -08002949 if (!rcu_fwds || !fwd_prog_tasks)
2950 return;
2951 for (i = 0; i < fwd_progress; i++)
2952 torture_stop_kthread(rcu_torture_fwd_prog, fwd_prog_tasks[i]);
2953 unregister_oom_notifier(&rcutorture_oom_nb);
Paul E. McKenney57f60202020-07-20 08:34:07 -07002954 mutex_lock(&rcu_fwd_mutex);
Paul E. McKenney82e31002021-11-22 20:55:18 -08002955 rfp = rcu_fwds;
Paul E. McKenneyc8fa6372020-07-19 14:40:31 -07002956 rcu_fwds = NULL;
Paul E. McKenney57f60202020-07-20 08:34:07 -07002957 mutex_unlock(&rcu_fwd_mutex);
Paul E. McKenneyc8fa6372020-07-19 14:40:31 -07002958 kfree(rfp);
Paul E. McKenney82e31002021-11-22 20:55:18 -08002959 kfree(fwd_prog_tasks);
2960 fwd_prog_tasks = NULL;
Paul E. McKenneyc8fa6372020-07-19 14:40:31 -07002961}
2962
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08002963/* Callback function for RCU barrier testing. */
Rashika Kheriab3b8a4d2014-02-27 17:16:57 +05302964static void rcu_torture_barrier_cbf(struct rcu_head *rcu)
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08002965{
2966 atomic_inc(&barrier_cbs_invoked);
2967}
2968
Paul E. McKenney50d4b622020-02-04 15:00:56 -08002969/* IPI handler to get callback posted on desired CPU, if online. */
2970static void rcu_torture_barrier1cb(void *rcu_void)
2971{
2972 struct rcu_head *rhp = rcu_void;
2973
2974 cur_ops->call(rhp, rcu_torture_barrier_cbf);
2975}
2976
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08002977/* kthread function to register callbacks used to test RCU barriers. */
2978static int rcu_torture_barrier_cbs(void *arg)
2979{
2980 long myid = (long)arg;
Jules Irenge8f43d592020-06-01 19:45:48 +01002981 bool lastphase = false;
Paul E. McKenney78e4bc32013-09-24 15:04:06 -07002982 bool newphase;
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08002983 struct rcu_head rcu;
2984
2985 init_rcu_head_on_stack(&rcu);
Paul E. McKenney5ccf60f2014-01-29 07:25:25 -08002986 VERBOSE_TOROUT_STRING("rcu_torture_barrier_cbs task started");
Linus Torvalds971eae72014-03-31 11:21:19 -07002987 set_user_nice(current, MAX_NICE);
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08002988 do {
2989 wait_event(barrier_cbs_wq[myid],
Paul E. McKenney78e4bc32013-09-24 15:04:06 -07002990 (newphase =
Paul E. McKenney6c7ed422015-04-13 11:58:08 -07002991 smp_load_acquire(&barrier_phase)) != lastphase ||
Paul E. McKenney36970bb2014-01-30 15:49:29 -08002992 torture_must_stop());
Paul E. McKenney78e4bc32013-09-24 15:04:06 -07002993 lastphase = newphase;
Paul E. McKenney36970bb2014-01-30 15:49:29 -08002994 if (torture_must_stop())
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08002995 break;
Paul E. McKenney6c7ed422015-04-13 11:58:08 -07002996 /*
2997 * The above smp_load_acquire() ensures barrier_phase load
Paul E. McKenneyaab05732016-05-02 12:20:51 -07002998 * is ordered before the following ->call().
Paul E. McKenney6c7ed422015-04-13 11:58:08 -07002999 */
Paul E. McKenney50d4b622020-02-04 15:00:56 -08003000 if (smp_call_function_single(myid, rcu_torture_barrier1cb,
3001 &rcu, 1)) {
3002 // IPI failed, so use direct call from current CPU.
3003 cur_ops->call(&rcu, rcu_torture_barrier_cbf);
3004 }
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08003005 if (atomic_dec_and_test(&barrier_cbs_count))
3006 wake_up(&barrier_wq);
Paul E. McKenney36970bb2014-01-30 15:49:29 -08003007 } while (!torture_must_stop());
Paul E. McKenney69c60452014-07-01 11:59:36 -07003008 if (cur_ops->cb_barrier != NULL)
3009 cur_ops->cb_barrier();
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08003010 destroy_rcu_head_on_stack(&rcu);
Paul E. McKenney7fafaac2014-01-31 17:37:28 -08003011 torture_kthread_stopping("rcu_torture_barrier_cbs");
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08003012 return 0;
3013}
3014
3015/* kthread function to drive and coordinate RCU barrier testing. */
3016static int rcu_torture_barrier(void *arg)
3017{
3018 int i;
3019
Paul E. McKenney5ccf60f2014-01-29 07:25:25 -08003020 VERBOSE_TOROUT_STRING("rcu_torture_barrier task starting");
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08003021 do {
3022 atomic_set(&barrier_cbs_invoked, 0);
3023 atomic_set(&barrier_cbs_count, n_barrier_cbs);
Paul E. McKenney6c7ed422015-04-13 11:58:08 -07003024 /* Ensure barrier_phase ordered after prior assignments. */
3025 smp_store_release(&barrier_phase, !barrier_phase);
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08003026 for (i = 0; i < n_barrier_cbs; i++)
3027 wake_up(&barrier_cbs_wq[i]);
3028 wait_event(barrier_wq,
3029 atomic_read(&barrier_cbs_count) == 0 ||
Paul E. McKenney36970bb2014-01-30 15:49:29 -08003030 torture_must_stop());
3031 if (torture_must_stop())
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08003032 break;
3033 n_barrier_attempts++;
Paul E. McKenney78e4bc32013-09-24 15:04:06 -07003034 cur_ops->cb_barrier(); /* Implies smp_mb() for wait_event(). */
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08003035 if (atomic_read(&barrier_cbs_invoked) != n_barrier_cbs) {
3036 n_rcu_torture_barrier_error++;
Paul E. McKenney7602de4a2014-12-17 18:39:54 -08003037 pr_err("barrier_cbs_invoked = %d, n_barrier_cbs = %d\n",
3038 atomic_read(&barrier_cbs_invoked),
3039 n_barrier_cbs);
Paul E. McKenney9470a182020-02-05 12:54:34 -08003040 WARN_ON(1);
3041 // Wait manually for the remaining callbacks
3042 i = 0;
3043 do {
3044 if (WARN_ON(i++ > HZ))
3045 i = INT_MIN;
3046 schedule_timeout_interruptible(1);
3047 cur_ops->cb_barrier();
3048 } while (atomic_read(&barrier_cbs_invoked) !=
3049 n_barrier_cbs &&
3050 !torture_must_stop());
3051 smp_mb(); // Can't trust ordering if broken.
3052 if (!torture_must_stop())
3053 pr_err("Recovered: barrier_cbs_invoked = %d\n",
3054 atomic_read(&barrier_cbs_invoked));
Joel Fernandes (Google)bf5b6432018-06-19 15:14:19 -07003055 } else {
3056 n_barrier_successes++;
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08003057 }
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08003058 schedule_timeout_interruptible(HZ / 10);
Paul E. McKenney36970bb2014-01-30 15:49:29 -08003059 } while (!torture_must_stop());
Paul E. McKenney7fafaac2014-01-31 17:37:28 -08003060 torture_kthread_stopping("rcu_torture_barrier");
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08003061 return 0;
3062}
3063
3064/* Initialize RCU barrier testing. */
3065static int rcu_torture_barrier_init(void)
3066{
3067 int i;
3068 int ret;
3069
Paul E. McKenneyd9eba7682015-05-14 15:35:43 -07003070 if (n_barrier_cbs <= 0)
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08003071 return 0;
3072 if (cur_ops->call == NULL || cur_ops->cb_barrier == NULL) {
Paul E. McKenney2caa1e42012-08-09 16:30:45 -07003073 pr_alert("%s" TORTURE_FLAG
3074 " Call or barrier ops missing for %s,\n",
3075 torture_type, cur_ops->name);
3076 pr_alert("%s" TORTURE_FLAG
3077 " RCU barrier testing omitted from run.\n",
3078 torture_type);
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08003079 return 0;
3080 }
3081 atomic_set(&barrier_cbs_count, 0);
3082 atomic_set(&barrier_cbs_invoked, 0);
3083 barrier_cbs_tasks =
Paul E. McKenney68a675d2017-12-01 14:26:56 -08003084 kcalloc(n_barrier_cbs, sizeof(barrier_cbs_tasks[0]),
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08003085 GFP_KERNEL);
3086 barrier_cbs_wq =
Paul E. McKenney68a675d2017-12-01 14:26:56 -08003087 kcalloc(n_barrier_cbs, sizeof(barrier_cbs_wq[0]), GFP_KERNEL);
Sasha Levinde5e6432012-12-20 14:11:28 -05003088 if (barrier_cbs_tasks == NULL || !barrier_cbs_wq)
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08003089 return -ENOMEM;
3090 for (i = 0; i < n_barrier_cbs; i++) {
3091 init_waitqueue_head(&barrier_cbs_wq[i]);
Paul E. McKenney47cf29b2014-02-03 11:52:27 -08003092 ret = torture_create_kthread(rcu_torture_barrier_cbs,
3093 (void *)(long)i,
3094 barrier_cbs_tasks[i]);
3095 if (ret)
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08003096 return ret;
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08003097 }
Paul E. McKenney47cf29b2014-02-03 11:52:27 -08003098 return torture_create_kthread(rcu_torture_barrier, NULL, barrier_task);
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08003099}
3100
3101/* Clean up after RCU barrier testing. */
3102static void rcu_torture_barrier_cleanup(void)
3103{
3104 int i;
3105
Paul E. McKenney9c029b82014-02-04 11:47:08 -08003106 torture_stop_kthread(rcu_torture_barrier, barrier_task);
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08003107 if (barrier_cbs_tasks != NULL) {
Paul E. McKenney9c029b82014-02-04 11:47:08 -08003108 for (i = 0; i < n_barrier_cbs; i++)
3109 torture_stop_kthread(rcu_torture_barrier_cbs,
3110 barrier_cbs_tasks[i]);
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08003111 kfree(barrier_cbs_tasks);
3112 barrier_cbs_tasks = NULL;
3113 }
3114 if (barrier_cbs_wq != NULL) {
3115 kfree(barrier_cbs_wq);
3116 barrier_cbs_wq = NULL;
3117 }
3118}
3119
Joel Fernandes (Google)4babd852018-06-19 15:14:18 -07003120static bool rcu_torture_can_boost(void)
3121{
3122 static int boost_warn_once;
3123 int prio;
3124
3125 if (!(test_boost == 1 && cur_ops->can_boost) && test_boost != 2)
3126 return false;
Paul E. McKenneyea6d9622021-03-30 16:30:32 -07003127 if (!cur_ops->start_gp_poll || !cur_ops->poll_gp_state)
Paul E. McKenney5e59fba2021-01-15 13:30:38 -08003128 return false;
Joel Fernandes (Google)4babd852018-06-19 15:14:18 -07003129
3130 prio = rcu_get_gp_kthreads_prio();
3131 if (!prio)
3132 return false;
3133
3134 if (prio < 2) {
Paul E. McKenneyea6d9622021-03-30 16:30:32 -07003135 if (boost_warn_once == 1)
Joel Fernandes (Google)4babd852018-06-19 15:14:18 -07003136 return false;
3137
Joel Fernandes (Google)bf5b6432018-06-19 15:14:19 -07003138 pr_alert("%s: WARN: RCU kthread priority too low to test boosting. Skipping RCU boost test. Try passing rcutree.kthread_prio > 1 on the kernel command line.\n", KBUILD_MODNAME);
Joel Fernandes (Google)4babd852018-06-19 15:14:18 -07003139 boost_warn_once = 1;
3140 return false;
3141 }
3142
3143 return true;
3144}
3145
Paul E. McKenney4a5f1332020-04-24 11:21:40 -07003146static bool read_exit_child_stop;
3147static bool read_exit_child_stopped;
3148static wait_queue_head_t read_exit_wq;
3149
3150// Child kthread which just does an rcutorture reader and exits.
3151static int rcu_torture_read_exit_child(void *trsp_in)
3152{
3153 struct torture_random_state *trsp = trsp_in;
3154
3155 set_user_nice(current, MAX_NICE);
3156 // Minimize time between reading and exiting.
3157 while (!kthread_should_stop())
3158 schedule_timeout_uninterruptible(1);
Paul E. McKenney00504532020-10-29 15:08:57 -07003159 (void)rcu_torture_one_read(trsp, -1);
Paul E. McKenney4a5f1332020-04-24 11:21:40 -07003160 return 0;
3161}
3162
3163// Parent kthread which creates and destroys read-exit child kthreads.
3164static int rcu_torture_read_exit(void *unused)
3165{
Paul E. McKenney4a5f1332020-04-24 11:21:40 -07003166 bool errexit = false;
3167 int i;
3168 struct task_struct *tsp;
3169 DEFINE_TORTURE_RANDOM(trs);
3170
3171 // Allocate and initialize.
3172 set_user_nice(current, MAX_NICE);
3173 VERBOSE_TOROUT_STRING("rcu_torture_read_exit: Start of test");
3174
3175 // Each pass through this loop does one read-exit episode.
3176 do {
Paul E. McKenneyd9841142022-04-27 11:46:02 -07003177 VERBOSE_TOROUT_STRING("rcu_torture_read_exit: Start of episode");
3178 for (i = 0; i < read_exit_burst; i++) {
3179 if (READ_ONCE(read_exit_child_stop))
3180 break;
3181 stutter_wait("rcu_torture_read_exit");
3182 // Spawn child.
3183 tsp = kthread_run(rcu_torture_read_exit_child,
3184 &trs, "%s", "rcu_torture_read_exit_child");
3185 if (IS_ERR(tsp)) {
3186 TOROUT_ERRSTRING("out of memory");
3187 errexit = true;
3188 break;
Paul E. McKenney4a5f1332020-04-24 11:21:40 -07003189 }
Paul E. McKenneyd9841142022-04-27 11:46:02 -07003190 cond_resched();
3191 kthread_stop(tsp);
3192 n_read_exits++;
Paul E. McKenney4a5f1332020-04-24 11:21:40 -07003193 }
Paul E. McKenneyd9841142022-04-27 11:46:02 -07003194 VERBOSE_TOROUT_STRING("rcu_torture_read_exit: End of episode");
3195 rcu_barrier(); // Wait for task_struct free, avoid OOM.
3196 i = 0;
3197 for (; !errexit && !READ_ONCE(read_exit_child_stop) && i < read_exit_delay; i++)
3198 schedule_timeout_uninterruptible(HZ);
Paul E. McKenney4a5f1332020-04-24 11:21:40 -07003199 } while (!errexit && !READ_ONCE(read_exit_child_stop));
3200
3201 // Clean up and exit.
3202 smp_store_release(&read_exit_child_stopped, true); // After reaping.
3203 smp_mb(); // Store before wakeup.
3204 wake_up(&read_exit_wq);
3205 while (!torture_must_stop())
3206 schedule_timeout_uninterruptible(1);
3207 torture_kthread_stopping("rcu_torture_read_exit");
3208 return 0;
3209}
3210
3211static int rcu_torture_read_exit_init(void)
3212{
3213 if (read_exit_burst <= 0)
Paul E. McKenneyfda84862021-08-03 17:42:25 -07003214 return 0;
Paul E. McKenney4a5f1332020-04-24 11:21:40 -07003215 init_waitqueue_head(&read_exit_wq);
3216 read_exit_child_stop = false;
3217 read_exit_child_stopped = false;
3218 return torture_create_kthread(rcu_torture_read_exit, NULL,
3219 read_exit_task);
3220}
3221
3222static void rcu_torture_read_exit_cleanup(void)
3223{
3224 if (!read_exit_task)
3225 return;
3226 WRITE_ONCE(read_exit_child_stop, true);
3227 smp_mb(); // Above write before wait.
3228 wait_event(read_exit_wq, smp_load_acquire(&read_exit_child_stopped));
3229 torture_stop_kthread(rcutorture_read_exit, read_exit_task);
3230}
3231
Sebastian Andrzej Siewior0ffd3742016-08-18 14:57:22 +02003232static enum cpuhp_state rcutor_hp;
Paul E. McKenney8e8be452010-09-02 16:16:14 -07003233
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003234static void
3235rcu_torture_cleanup(void)
3236{
Paul E. McKenneyc116dba2018-07-13 12:09:14 -07003237 int firsttime;
Paul E. McKenney034777d2018-04-19 08:43:11 -07003238 int flags = 0;
Paul E. McKenneyaebc8262018-05-01 06:42:51 -07003239 unsigned long gp_seq = 0;
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003240 int i;
3241
Davidlohr Buesod36a7a02014-09-11 20:40:21 -07003242 if (torture_cleanup_begin()) {
Paul E. McKenney6f81bd62021-12-06 15:12:14 -08003243 if (cur_ops->cb_barrier != NULL) {
3244 pr_info("%s: Invoking %pS().\n", __func__, cur_ops->cb_barrier);
Paul E. McKenney343e9092008-12-15 16:13:07 -08003245 cur_ops->cb_barrier();
Paul E. McKenney6f81bd62021-12-06 15:12:14 -08003246 }
Paul E. McKenney99d6a2a2022-02-04 12:45:18 -08003247 rcu_gp_slow_unregister(NULL);
Paul E. McKenney343e9092008-12-15 16:13:07 -08003248 return;
3249 }
Paul E. McKenneyb813afa2019-03-21 09:27:28 -07003250 if (!cur_ops) {
3251 torture_cleanup_end();
Paul E. McKenney99d6a2a2022-02-04 12:45:18 -08003252 rcu_gp_slow_unregister(NULL);
Paul E. McKenneyb813afa2019-03-21 09:27:28 -07003253 return;
3254 }
Paul E. McKenney3808dc92014-01-28 15:29:21 -08003255
Paul E. McKenney27c0f142020-09-15 17:08:03 -07003256 if (cur_ops->gp_kthread_dbg)
3257 cur_ops->gp_kthread_dbg();
Paul E. McKenney4a5f1332020-04-24 11:21:40 -07003258 rcu_torture_read_exit_cleanup();
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08003259 rcu_torture_barrier_cleanup();
Paul E. McKenneyc8fa6372020-07-19 14:40:31 -07003260 rcu_torture_fwd_prog_cleanup();
Paul E. McKenney9c029b82014-02-04 11:47:08 -08003261 torture_stop_kthread(rcu_torture_stall, stall_task);
Paul E. McKenney9c029b82014-02-04 11:47:08 -08003262 torture_stop_kthread(rcu_torture_writer, writer_task);
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003263
Paul E. McKenney2c4319b2020-09-23 17:39:46 -07003264 if (nocb_tasks) {
3265 for (i = 0; i < nrealnocbers; i++)
3266 torture_stop_kthread(rcu_nocb_toggle, nocb_tasks[i]);
3267 kfree(nocb_tasks);
3268 nocb_tasks = NULL;
3269 }
3270
Josh Triplettc8e5b162007-05-08 00:33:20 -07003271 if (reader_tasks) {
Paul E. McKenney9c029b82014-02-04 11:47:08 -08003272 for (i = 0; i < nrealreaders; i++)
3273 torture_stop_kthread(rcu_torture_reader,
3274 reader_tasks[i]);
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003275 kfree(reader_tasks);
Paul E. McKenney293b93d2020-09-23 16:46:36 -07003276 reader_tasks = NULL;
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003277 }
Paul E. McKenney00504532020-10-29 15:08:57 -07003278 kfree(rcu_torture_reader_mbchk);
3279 rcu_torture_reader_mbchk = NULL;
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003280
Josh Triplettc8e5b162007-05-08 00:33:20 -07003281 if (fakewriter_tasks) {
Paul E. McKenney293b93d2020-09-23 16:46:36 -07003282 for (i = 0; i < nfakewriters; i++)
Paul E. McKenney9c029b82014-02-04 11:47:08 -08003283 torture_stop_kthread(rcu_torture_fakewriter,
3284 fakewriter_tasks[i]);
Josh Triplettb772e1d2006-10-04 02:17:13 -07003285 kfree(fakewriter_tasks);
3286 fakewriter_tasks = NULL;
3287 }
3288
Paul E. McKenneyaebc8262018-05-01 06:42:51 -07003289 rcutorture_get_gp_data(cur_ops->ttype, &flags, &gp_seq);
3290 srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp, &flags, &gp_seq);
Joel Fernandes (Google)959954d2020-06-18 16:29:55 -04003291 pr_alert("%s: End-test grace-period state: g%ld f%#x total-gps=%ld\n",
3292 cur_ops->name, (long)gp_seq, flags,
3293 rcutorture_seq_diff(gp_seq, start_gp_seq));
Paul E. McKenney9c029b82014-02-04 11:47:08 -08003294 torture_stop_kthread(rcu_torture_stats, stats_task);
3295 torture_stop_kthread(rcu_torture_fqs, fqs_task);
Paul E. McKenneyfd13fe12021-08-06 08:57:26 -07003296 if (rcu_torture_can_boost() && rcutor_hp >= 0)
Sebastian Andrzej Siewior0ffd3742016-08-18 14:57:22 +02003297 cpuhp_remove_state(rcutor_hp);
Paul E. McKenneybf66f182010-01-04 15:09:10 -08003298
Paul E. McKenneyca1d51e2015-04-14 12:28:22 -07003299 /*
Paul E. McKenney62a1a942018-07-07 18:12:26 -07003300 * Wait for all RCU callbacks to fire, then do torture-type-specific
Paul E. McKenneyca1d51e2015-04-14 12:28:22 -07003301 * cleanup operations.
3302 */
Paul E. McKenney6f81bd62021-12-06 15:12:14 -08003303 if (cur_ops->cb_barrier != NULL) {
3304 pr_info("%s: Invoking %pS().\n", __func__, cur_ops->cb_barrier);
Paul E. McKenney23269742008-05-12 21:21:05 +02003305 cur_ops->cb_barrier();
Paul E. McKenney6f81bd62021-12-06 15:12:14 -08003306 }
Paul E. McKenneyca1d51e2015-04-14 12:28:22 -07003307 if (cur_ops->cleanup != NULL)
3308 cur_ops->cleanup();
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003309
Paul E. McKenney7ab2bd32021-05-02 19:56:05 -07003310 rcu_torture_mem_dump_obj();
3311
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003312 rcu_torture_stats_print(); /* -After- the stats thread is stopped! */
Paul E. McKenney72e9bb52006-06-27 02:54:03 -07003313
Paul E. McKenneyc116dba2018-07-13 12:09:14 -07003314 if (err_segs_recorded) {
3315 pr_alert("Failure/close-call rcutorture reader segments:\n");
3316 if (rt_read_nsegs == 0)
3317 pr_alert("\t: No segments recorded!!!\n");
3318 firsttime = 1;
3319 for (i = 0; i < rt_read_nsegs; i++) {
3320 pr_alert("\t%d: %#x ", i, err_segs[i].rt_readstate);
3321 if (err_segs[i].rt_delay_jiffies != 0) {
3322 pr_cont("%s%ldjiffies", firsttime ? "" : "+",
3323 err_segs[i].rt_delay_jiffies);
3324 firsttime = 0;
3325 }
3326 if (err_segs[i].rt_delay_ms != 0) {
3327 pr_cont("%s%ldms", firsttime ? "" : "+",
3328 err_segs[i].rt_delay_ms);
3329 firsttime = 0;
3330 }
3331 if (err_segs[i].rt_delay_us != 0) {
3332 pr_cont("%s%ldus", firsttime ? "" : "+",
3333 err_segs[i].rt_delay_us);
3334 firsttime = 0;
3335 }
3336 pr_cont("%s\n",
3337 err_segs[i].rt_preempted ? "preempted" : "");
3338
3339 }
3340 }
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08003341 if (atomic_read(&n_rcu_torture_error) || n_rcu_torture_barrier_error)
Paul E. McKenney8e8be452010-09-02 16:16:14 -07003342 rcu_torture_print_module_parms(cur_ops, "End of test: FAILURE");
Paul E. McKenney2e9e8082014-01-28 15:58:22 -08003343 else if (torture_onoff_failures())
Paul E. McKenney091541b2012-01-10 12:51:14 -08003344 rcu_torture_print_module_parms(cur_ops,
3345 "End of test: RCU_HOTPLUG");
Paul E. McKenney95c38322006-03-24 03:15:58 -08003346 else
Paul E. McKenney8e8be452010-09-02 16:16:14 -07003347 rcu_torture_print_module_parms(cur_ops, "End of test: SUCCESS");
Davidlohr Buesod36a7a02014-09-11 20:40:21 -07003348 torture_cleanup_end();
Paul E. McKenney99d6a2a2022-02-04 12:45:18 -08003349 rcu_gp_slow_unregister(&rcu_fwd_cb_nodelay);
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003350}
3351
Paul E. McKenneyd2818df2013-04-23 17:05:42 -07003352#ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
3353static void rcu_torture_leak_cb(struct rcu_head *rhp)
3354{
3355}
3356
3357static void rcu_torture_err_cb(struct rcu_head *rhp)
3358{
3359 /*
3360 * This -might- happen due to race conditions, but is unlikely.
3361 * The scenario that leads to this happening is that the
3362 * first of the pair of duplicate callbacks is queued,
3363 * someone else starts a grace period that includes that
3364 * callback, then the second of the pair must wait for the
3365 * next grace period. Unlikely, but can happen. If it
3366 * does happen, the debug-objects subsystem won't have splatted.
3367 */
Paul E. McKenneye0d31a34c2017-12-01 15:22:38 -08003368 pr_alert("%s: duplicated callback was invoked.\n", KBUILD_MODNAME);
Paul E. McKenneyd2818df2013-04-23 17:05:42 -07003369}
3370#endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
3371
3372/*
3373 * Verify that double-free causes debug-objects to complain, but only
3374 * if CONFIG_DEBUG_OBJECTS_RCU_HEAD=y. Otherwise, say that the test
3375 * cannot be carried out.
3376 */
3377static void rcu_test_debug_objects(void)
3378{
3379#ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
3380 struct rcu_head rh1;
3381 struct rcu_head rh2;
Paul E. McKenneyedf7b842020-12-02 17:52:07 -08003382 struct rcu_head *rhp = kmalloc(sizeof(*rhp), GFP_KERNEL);
Paul E. McKenneyd2818df2013-04-23 17:05:42 -07003383
3384 init_rcu_head_on_stack(&rh1);
3385 init_rcu_head_on_stack(&rh2);
Paul E. McKenneye0d31a34c2017-12-01 15:22:38 -08003386 pr_alert("%s: WARN: Duplicate call_rcu() test starting.\n", KBUILD_MODNAME);
Paul E. McKenneyd2818df2013-04-23 17:05:42 -07003387
3388 /* Try to queue the rh2 pair of callbacks for the same grace period. */
3389 preempt_disable(); /* Prevent preemption from interrupting test. */
3390 rcu_read_lock(); /* Make it impossible to finish a grace period. */
3391 call_rcu(&rh1, rcu_torture_leak_cb); /* Start grace period. */
3392 local_irq_disable(); /* Make it harder to start a new grace period. */
3393 call_rcu(&rh2, rcu_torture_leak_cb);
3394 call_rcu(&rh2, rcu_torture_err_cb); /* Duplicate callback. */
Paul E. McKenneyedf7b842020-12-02 17:52:07 -08003395 if (rhp) {
3396 call_rcu(rhp, rcu_torture_leak_cb);
3397 call_rcu(rhp, rcu_torture_err_cb); /* Another duplicate callback. */
3398 }
Paul E. McKenneyd2818df2013-04-23 17:05:42 -07003399 local_irq_enable();
3400 rcu_read_unlock();
3401 preempt_enable();
3402
3403 /* Wait for them all to get done so we can safely return. */
3404 rcu_barrier();
Paul E. McKenneye0d31a34c2017-12-01 15:22:38 -08003405 pr_alert("%s: WARN: Duplicate call_rcu() test complete.\n", KBUILD_MODNAME);
Paul E. McKenneyd2818df2013-04-23 17:05:42 -07003406 destroy_rcu_head_on_stack(&rh1);
3407 destroy_rcu_head_on_stack(&rh2);
Zqiang98ea2032022-04-27 15:15:20 +08003408 kfree(rhp);
Paul E. McKenneyd2818df2013-04-23 17:05:42 -07003409#else /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
Paul E. McKenneye0d31a34c2017-12-01 15:22:38 -08003410 pr_alert("%s: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_rcu()\n", KBUILD_MODNAME);
Paul E. McKenneyd2818df2013-04-23 17:05:42 -07003411#endif /* #else #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
3412}
3413
Paul E. McKenney3a6cb582018-12-10 09:44:52 -08003414static void rcutorture_sync(void)
3415{
3416 static unsigned long n;
3417
3418 if (cur_ops->sync && !(++n & 0xfff))
3419 cur_ops->sync();
3420}
3421
Josh Triplett6f8bc5002007-05-08 00:25:24 -07003422static int __init
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003423rcu_torture_init(void)
3424{
Paul E. McKenneyc04dd092018-07-23 14:16:47 -07003425 long i;
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003426 int cpu;
3427 int firsterr = 0;
Joel Fernandes (Google)959954d2020-06-18 16:29:55 -04003428 int flags = 0;
3429 unsigned long gp_seq = 0;
Paul E. McKenney2ec1f2d92013-06-12 15:12:21 -07003430 static struct rcu_torture_ops *torture_ops[] = {
Paul E. McKenney40c12782022-03-17 13:29:59 -07003431 &rcu_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops, &busted_srcud_ops,
Paul E. McKenney4c3f7b02022-03-17 16:16:45 -07003432 TASKS_OPS TASKS_RUDE_OPS TASKS_TRACING_OPS
Paul E. McKenney40c12782022-03-17 13:29:59 -07003433 &trivial_ops,
Paul E. McKenney2ec1f2d92013-06-12 15:12:21 -07003434 };
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003435
Paul E. McKenneya2f25772017-11-21 20:19:17 -08003436 if (!torture_init_begin(torture_type, verbose))
Paul E. McKenney52280842014-04-07 09:14:11 -07003437 return -EBUSY;
Paul E. McKenney343e9092008-12-15 16:13:07 -08003438
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003439 /* Process args and tell the world that the torturer is on the job. */
Josh Triplettade5fb82007-05-08 00:33:22 -07003440 for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
Paul E. McKenney72e9bb52006-06-27 02:54:03 -07003441 cur_ops = torture_ops[i];
Josh Triplettade5fb82007-05-08 00:33:22 -07003442 if (strcmp(torture_type, cur_ops->name) == 0)
Paul E. McKenney72e9bb52006-06-27 02:54:03 -07003443 break;
Paul E. McKenney72e9bb52006-06-27 02:54:03 -07003444 }
Josh Triplettade5fb82007-05-08 00:33:22 -07003445 if (i == ARRAY_SIZE(torture_ops)) {
Paul E. McKenney2caa1e42012-08-09 16:30:45 -07003446 pr_alert("rcu-torture: invalid torture type: \"%s\"\n",
3447 torture_type);
3448 pr_alert("rcu-torture types:");
Paul E. McKenneycf886c42009-10-25 19:03:54 -07003449 for (i = 0; i < ARRAY_SIZE(torture_ops); i++)
Joe Perchesa7538352018-05-14 13:27:33 -07003450 pr_cont(" %s", torture_ops[i]->name);
3451 pr_cont("\n");
Paul E. McKenney889d4872015-08-24 11:37:58 -07003452 firsterr = -EINVAL;
Paul E. McKenneyb813afa2019-03-21 09:27:28 -07003453 cur_ops = NULL;
Paul E. McKenney889d4872015-08-24 11:37:58 -07003454 goto unwind;
Paul E. McKenney72e9bb52006-06-27 02:54:03 -07003455 }
Paul E. McKenneybf66f182010-01-04 15:09:10 -08003456 if (cur_ops->fqs == NULL && fqs_duration != 0) {
Paul E. McKenney2caa1e42012-08-09 16:30:45 -07003457 pr_alert("rcu-torture: ->fqs NULL and non-zero fqs_duration, fqs disabled.\n");
Paul E. McKenneybf66f182010-01-04 15:09:10 -08003458 fqs_duration = 0;
3459 }
Josh Triplettc8e5b162007-05-08 00:33:20 -07003460 if (cur_ops->init)
Paul E. McKenney889d4872015-08-24 11:37:58 -07003461 cur_ops->init();
Paul E. McKenney72e9bb52006-06-27 02:54:03 -07003462
Paul E. McKenney64e4b432014-03-12 10:26:35 -07003463 if (nreaders >= 0) {
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003464 nrealreaders = nreaders;
Paul E. McKenney64e4b432014-03-12 10:26:35 -07003465 } else {
Paul E. McKenney3838cc12015-03-12 13:55:48 -07003466 nrealreaders = num_online_cpus() - 2 - nreaders;
Paul E. McKenney64e4b432014-03-12 10:26:35 -07003467 if (nrealreaders <= 0)
3468 nrealreaders = 1;
3469 }
Paul E. McKenney8e8be452010-09-02 16:16:14 -07003470 rcu_torture_print_module_parms(cur_ops, "Start of test");
Joel Fernandes (Google)959954d2020-06-18 16:29:55 -04003471 rcutorture_get_gp_data(cur_ops->ttype, &flags, &gp_seq);
3472 srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp, &flags, &gp_seq);
3473 start_gp_seq = gp_seq;
3474 pr_alert("%s: Start-test grace-period state: g%ld f%#x\n",
3475 cur_ops->name, (long)gp_seq, flags);
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003476
3477 /* Set up the freelist. */
3478
3479 INIT_LIST_HEAD(&rcu_torture_freelist);
Ahmed S. Darwish788e7702007-05-08 00:33:14 -07003480 for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) {
Paul E. McKenney996417d2005-11-18 01:10:50 -08003481 rcu_tortures[i].rtort_mbtest = 0;
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003482 list_add_tail(&rcu_tortures[i].rtort_free,
3483 &rcu_torture_freelist);
3484 }
3485
3486 /* Initialize the statistics so that each run gets its own numbers. */
3487
3488 rcu_torture_current = NULL;
3489 rcu_torture_current_version = 0;
3490 atomic_set(&n_rcu_torture_alloc, 0);
3491 atomic_set(&n_rcu_torture_alloc_fail, 0);
3492 atomic_set(&n_rcu_torture_free, 0);
Paul E. McKenney996417d2005-11-18 01:10:50 -08003493 atomic_set(&n_rcu_torture_mberror, 0);
Paul E. McKenney00504532020-10-29 15:08:57 -07003494 atomic_set(&n_rcu_torture_mbchk_fail, 0);
3495 atomic_set(&n_rcu_torture_mbchk_tries, 0);
Paul E. McKenney996417d2005-11-18 01:10:50 -08003496 atomic_set(&n_rcu_torture_error, 0);
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08003497 n_rcu_torture_barrier_error = 0;
Paul E. McKenney8e8be452010-09-02 16:16:14 -07003498 n_rcu_torture_boost_ktrerror = 0;
3499 n_rcu_torture_boost_rterror = 0;
Paul E. McKenney8e8be452010-09-02 16:16:14 -07003500 n_rcu_torture_boost_failure = 0;
3501 n_rcu_torture_boosts = 0;
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003502 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
3503 atomic_set(&rcu_torture_wcount[i], 0);
KAMEZAWA Hiroyuki0a945022006-03-28 01:56:37 -08003504 for_each_possible_cpu(cpu) {
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003505 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
3506 per_cpu(rcu_torture_count, cpu)[i] = 0;
3507 per_cpu(rcu_torture_batch, cpu)[i] = 0;
3508 }
3509 }
Paul E. McKenneyc116dba2018-07-13 12:09:14 -07003510 err_segs_recorded = 0;
3511 rt_read_nsegs = 0;
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003512
3513 /* Start up the kthreads. */
3514
Paul E. McKenney18fbf302020-11-16 16:46:06 -08003515 rcu_torture_write_types();
Paul E. McKenney47cf29b2014-02-03 11:52:27 -08003516 firsterr = torture_create_kthread(rcu_torture_writer, NULL,
3517 writer_task);
Paul E. McKenneyefeff6b2021-08-05 13:28:24 -07003518 if (torture_init_error(firsterr))
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003519 goto unwind;
Paul E. McKenney4444d852015-05-14 15:42:40 -07003520 if (nfakewriters > 0) {
Paul E. McKenney68a675d2017-12-01 14:26:56 -08003521 fakewriter_tasks = kcalloc(nfakewriters,
Paul E. McKenney4444d852015-05-14 15:42:40 -07003522 sizeof(fakewriter_tasks[0]),
3523 GFP_KERNEL);
3524 if (fakewriter_tasks == NULL) {
Li Zhijian81faa4f2021-11-03 16:30:28 +08003525 TOROUT_ERRSTRING("out of memory");
Paul E. McKenney4444d852015-05-14 15:42:40 -07003526 firsterr = -ENOMEM;
3527 goto unwind;
3528 }
Josh Triplettb772e1d2006-10-04 02:17:13 -07003529 }
3530 for (i = 0; i < nfakewriters; i++) {
Paul E. McKenney47cf29b2014-02-03 11:52:27 -08003531 firsterr = torture_create_kthread(rcu_torture_fakewriter,
3532 NULL, fakewriter_tasks[i]);
Paul E. McKenneyefeff6b2021-08-05 13:28:24 -07003533 if (torture_init_error(firsterr))
Josh Triplettb772e1d2006-10-04 02:17:13 -07003534 goto unwind;
Josh Triplettb772e1d2006-10-04 02:17:13 -07003535 }
Paul E. McKenney68a675d2017-12-01 14:26:56 -08003536 reader_tasks = kcalloc(nrealreaders, sizeof(reader_tasks[0]),
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003537 GFP_KERNEL);
Paul E. McKenney00504532020-10-29 15:08:57 -07003538 rcu_torture_reader_mbchk = kcalloc(nrealreaders, sizeof(*rcu_torture_reader_mbchk),
3539 GFP_KERNEL);
3540 if (!reader_tasks || !rcu_torture_reader_mbchk) {
Li Zhijian81faa4f2021-11-03 16:30:28 +08003541 TOROUT_ERRSTRING("out of memory");
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003542 firsterr = -ENOMEM;
3543 goto unwind;
3544 }
3545 for (i = 0; i < nrealreaders; i++) {
Paul E. McKenney00504532020-10-29 15:08:57 -07003546 rcu_torture_reader_mbchk[i].rtc_chkrdr = -1;
Paul E. McKenneyc04dd092018-07-23 14:16:47 -07003547 firsterr = torture_create_kthread(rcu_torture_reader, (void *)i,
Paul E. McKenney47cf29b2014-02-03 11:52:27 -08003548 reader_tasks[i]);
Paul E. McKenneyefeff6b2021-08-05 13:28:24 -07003549 if (torture_init_error(firsterr))
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003550 goto unwind;
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003551 }
Paul E. McKenney2c4319b2020-09-23 17:39:46 -07003552 nrealnocbers = nocbs_nthreads;
3553 if (WARN_ON(nrealnocbers < 0))
3554 nrealnocbers = 1;
3555 if (WARN_ON(nocbs_toggle < 0))
3556 nocbs_toggle = HZ;
3557 if (nrealnocbers > 0) {
3558 nocb_tasks = kcalloc(nrealnocbers, sizeof(nocb_tasks[0]), GFP_KERNEL);
3559 if (nocb_tasks == NULL) {
Li Zhijian81faa4f2021-11-03 16:30:28 +08003560 TOROUT_ERRSTRING("out of memory");
Paul E. McKenney2c4319b2020-09-23 17:39:46 -07003561 firsterr = -ENOMEM;
3562 goto unwind;
3563 }
3564 } else {
3565 nocb_tasks = NULL;
3566 }
3567 for (i = 0; i < nrealnocbers; i++) {
3568 firsterr = torture_create_kthread(rcu_nocb_toggle, NULL, nocb_tasks[i]);
Paul E. McKenneyefeff6b2021-08-05 13:28:24 -07003569 if (torture_init_error(firsterr))
Paul E. McKenney2c4319b2020-09-23 17:39:46 -07003570 goto unwind;
3571 }
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003572 if (stat_interval > 0) {
Paul E. McKenney47cf29b2014-02-03 11:52:27 -08003573 firsterr = torture_create_kthread(rcu_torture_stats, NULL,
3574 stats_task);
Paul E. McKenneyefeff6b2021-08-05 13:28:24 -07003575 if (torture_init_error(firsterr))
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003576 goto unwind;
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003577 }
Paul E. McKenneye8e255f2015-05-14 16:55:45 -07003578 if (test_no_idle_hz && shuffle_interval > 0) {
Paul E. McKenney3808dc92014-01-28 15:29:21 -08003579 firsterr = torture_shuffle_init(shuffle_interval * HZ);
Paul E. McKenneyefeff6b2021-08-05 13:28:24 -07003580 if (torture_init_error(firsterr))
Rusty Russell73d0a4b2009-03-30 22:05:16 -06003581 goto unwind;
Srivatsa Vaddagirid84f5202006-01-08 01:03:42 -08003582 }
Paul E. McKenneyd120f652008-06-18 05:21:44 -07003583 if (stutter < 0)
3584 stutter = 0;
3585 if (stutter) {
Paul E. McKenneyff3bf922019-04-09 14:44:49 -07003586 int t;
3587
3588 t = cur_ops->stall_dur ? cur_ops->stall_dur() : stutter * HZ;
3589 firsterr = torture_stutter_init(stutter * HZ, t);
Paul E. McKenneyefeff6b2021-08-05 13:28:24 -07003590 if (torture_init_error(firsterr))
Paul E. McKenneyd120f652008-06-18 05:21:44 -07003591 goto unwind;
Paul E. McKenneyd120f652008-06-18 05:21:44 -07003592 }
Paul E. McKenneybf66f182010-01-04 15:09:10 -08003593 if (fqs_duration < 0)
3594 fqs_duration = 0;
3595 if (fqs_duration) {
Paul E. McKenney628edaa2014-01-31 11:57:43 -08003596 /* Create the fqs thread */
Paul E. McKenneyd0d06062014-03-17 20:56:45 -07003597 firsterr = torture_create_kthread(rcu_torture_fqs, NULL,
3598 fqs_task);
Paul E. McKenneyefeff6b2021-08-05 13:28:24 -07003599 if (torture_init_error(firsterr))
Paul E. McKenneybf66f182010-01-04 15:09:10 -08003600 goto unwind;
Paul E. McKenneybf66f182010-01-04 15:09:10 -08003601 }
Paul E. McKenney8e8be452010-09-02 16:16:14 -07003602 if (test_boost_interval < 1)
3603 test_boost_interval = 1;
3604 if (test_boost_duration < 2)
3605 test_boost_duration = 2;
Joel Fernandes (Google)4babd852018-06-19 15:14:18 -07003606 if (rcu_torture_can_boost()) {
Paul E. McKenney8e8be452010-09-02 16:16:14 -07003607
3608 boost_starttime = jiffies + test_boost_interval * HZ;
Sebastian Andrzej Siewior0ffd3742016-08-18 14:57:22 +02003609
3610 firsterr = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "RCU_TORTURE",
3611 rcutorture_booster_init,
3612 rcutorture_booster_cleanup);
Sebastian Andrzej Siewior0ffd3742016-08-18 14:57:22 +02003613 rcutor_hp = firsterr;
Paul E. McKenneyefeff6b2021-08-05 13:28:24 -07003614 if (torture_init_error(firsterr))
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003615 goto unwind;
Paul E. McKenney8e8be452010-09-02 16:16:14 -07003616 }
Paul E. McKenney60013d52019-07-10 08:30:00 -07003617 shutdown_jiffies = jiffies + shutdown_secs * HZ;
Paul E. McKenney01025eb2014-01-31 15:15:02 -08003618 firsterr = torture_shutdown_init(shutdown_secs, rcu_torture_cleanup);
Paul E. McKenneyefeff6b2021-08-05 13:28:24 -07003619 if (torture_init_error(firsterr))
Paul E. McKenneye991dbc2014-01-31 14:52:13 -08003620 goto unwind;
Paul E. McKenney3a6cb582018-12-10 09:44:52 -08003621 firsterr = torture_onoff_init(onoff_holdoff * HZ, onoff_interval,
3622 rcutorture_sync);
Paul E. McKenneyefeff6b2021-08-05 13:28:24 -07003623 if (torture_init_error(firsterr))
Paul E. McKenney37e377d2012-02-17 22:12:18 -08003624 goto unwind;
Paul E. McKenney01025eb2014-01-31 15:15:02 -08003625 firsterr = rcu_torture_stall_init();
Paul E. McKenneyefeff6b2021-08-05 13:28:24 -07003626 if (torture_init_error(firsterr))
Paul E. McKenney37e377d2012-02-17 22:12:18 -08003627 goto unwind;
Paul E. McKenney1b272912018-07-18 14:32:31 -07003628 firsterr = rcu_torture_fwd_prog_init();
Paul E. McKenneyefeff6b2021-08-05 13:28:24 -07003629 if (torture_init_error(firsterr))
Paul E. McKenney1b272912018-07-18 14:32:31 -07003630 goto unwind;
Paul E. McKenney01025eb2014-01-31 15:15:02 -08003631 firsterr = rcu_torture_barrier_init();
Paul E. McKenneyefeff6b2021-08-05 13:28:24 -07003632 if (torture_init_error(firsterr))
Paul E. McKenneyfae4b542012-02-20 17:51:45 -08003633 goto unwind;
Paul E. McKenney4a5f1332020-04-24 11:21:40 -07003634 firsterr = rcu_torture_read_exit_init();
Paul E. McKenneyefeff6b2021-08-05 13:28:24 -07003635 if (torture_init_error(firsterr))
Paul E. McKenney4a5f1332020-04-24 11:21:40 -07003636 goto unwind;
Paul E. McKenneyd2818df2013-04-23 17:05:42 -07003637 if (object_debug)
3638 rcu_test_debug_objects();
Paul E. McKenneyb5daa8f2014-01-30 13:38:09 -08003639 torture_init_end();
Paul E. McKenney99d6a2a2022-02-04 12:45:18 -08003640 rcu_gp_slow_register(&rcu_fwd_cb_nodelay);
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003641 return 0;
3642
3643unwind:
Paul E. McKenneyb5daa8f2014-01-30 13:38:09 -08003644 torture_init_end();
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003645 rcu_torture_cleanup();
Paul E. McKenney49946842020-09-18 13:30:33 -07003646 if (shutdown_secs) {
3647 WARN_ON(!IS_MODULE(CONFIG_RCU_TORTURE_TEST));
3648 kernel_power_off();
3649 }
Paul E. McKenneya241ec62005-10-30 15:03:12 -08003650 return firsterr;
3651}
3652
3653module_init(rcu_torture_init);
3654module_exit(rcu_torture_cleanup);