Merge branches 'fixes.2021.10.07a', 'scftorture.2021.09.16a', 'tasks.2021.09.15a', 'torture.2021.09.13b' and 'torturescript.2021.09.16a' into HEAD
fixes.2021.10.07a: Miscellaneous fixes.
scftorture.2021.09.16a: smp_call_function torture-test updates.
tasks.2021.09.15a: Tasks-trace RCU updates.
torture.2021.09.13b: Other torture-test updates.
torturescript.2021.09.16a: Torture-test scripting updates.
diff --git a/include/linux/rcupdate_trace.h b/include/linux/rcupdate_trace.h
index 86c8f6c..6f9c358 100644
--- a/include/linux/rcupdate_trace.h
+++ b/include/linux/rcupdate_trace.h
@@ -31,7 +31,7 @@ static inline int rcu_read_lock_trace_held(void)
#ifdef CONFIG_TASKS_TRACE_RCU
-void rcu_read_unlock_trace_special(struct task_struct *t, int nesting);
+void rcu_read_unlock_trace_special(struct task_struct *t);
/**
* rcu_read_lock_trace - mark beginning of RCU-trace read-side critical section
@@ -80,7 +80,8 @@ static inline void rcu_read_unlock_trace(void)
WRITE_ONCE(t->trc_reader_nesting, nesting);
return; // We assume shallow reader nesting.
}
- rcu_read_unlock_trace_special(t, nesting);
+ WARN_ON_ONCE(nesting != 0);
+ rcu_read_unlock_trace_special(t);
}
void call_rcu_tasks_trace(struct rcu_head *rhp, rcu_callback_t func);
diff --git a/include/linux/torture.h b/include/linux/torture.h
index 0910c58..24f58e5 100644
--- a/include/linux/torture.h
+++ b/include/linux/torture.h
@@ -47,6 +47,14 @@ do { \
} while (0)
void verbose_torout_sleep(void);
+#define torture_init_error(firsterr) \
+({ \
+ int ___firsterr = (firsterr); \
+ \
+ WARN_ONCE(!IS_MODULE(CONFIG_RCU_TORTURE_TEST) && ___firsterr < 0, "Torture-test initialization failed with error code %d\n", ___firsterr); \
+ ___firsterr < 0; \
+})
+
/* Definitions for online/offline exerciser. */
#ifdef CONFIG_HOTPLUG_CPU
int torture_num_online_cpus(void);
diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
index 7c5a4a0..397ac13 100644
--- a/kernel/locking/locktorture.c
+++ b/kernel/locking/locktorture.c
@@ -1022,23 +1022,23 @@ static int __init lock_torture_init(void)
if (onoff_interval > 0) {
firsterr = torture_onoff_init(onoff_holdoff * HZ,
onoff_interval * HZ, NULL);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
}
if (shuffle_interval > 0) {
firsterr = torture_shuffle_init(shuffle_interval);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
}
if (shutdown_secs > 0) {
firsterr = torture_shutdown_init(shutdown_secs,
lock_torture_cleanup);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
}
if (stutter > 0) {
firsterr = torture_stutter_init(stutter, stutter);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
}
@@ -1082,7 +1082,7 @@ static int __init lock_torture_init(void)
/* Create writer. */
firsterr = torture_create_kthread(lock_torture_writer, &cxt.lwsa[i],
writer_tasks[i]);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
create_reader:
@@ -1091,13 +1091,13 @@ static int __init lock_torture_init(void)
/* Create reader. */
firsterr = torture_create_kthread(lock_torture_reader, &cxt.lrsa[j],
reader_tasks[j]);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
}
if (stat_interval > 0) {
firsterr = torture_create_kthread(lock_torture_stats, NULL,
stats_task);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
}
torture_init_end();
diff --git a/kernel/rcu/rcuscale.c b/kernel/rcu/rcuscale.c
index 2cc34a2..228f143 100644
--- a/kernel/rcu/rcuscale.c
+++ b/kernel/rcu/rcuscale.c
@@ -758,7 +758,7 @@ kfree_scale_init(void)
init_waitqueue_head(&shutdown_wq);
firsterr = torture_create_kthread(kfree_scale_shutdown, NULL,
shutdown_task);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
schedule_timeout_uninterruptible(1);
}
@@ -775,7 +775,7 @@ kfree_scale_init(void)
for (i = 0; i < kfree_nrealthreads; i++) {
firsterr = torture_create_kthread(kfree_scale_thread, (void *)i,
kfree_reader_tasks[i]);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
}
@@ -838,7 +838,7 @@ rcu_scale_init(void)
init_waitqueue_head(&shutdown_wq);
firsterr = torture_create_kthread(rcu_scale_shutdown, NULL,
shutdown_task);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
schedule_timeout_uninterruptible(1);
}
@@ -852,7 +852,7 @@ rcu_scale_init(void)
for (i = 0; i < nrealreaders; i++) {
firsterr = torture_create_kthread(rcu_scale_reader, (void *)i,
reader_tasks[i]);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
}
while (atomic_read(&n_rcu_scale_reader_started) < nrealreaders)
@@ -879,7 +879,7 @@ rcu_scale_init(void)
}
firsterr = torture_create_kthread(rcu_scale_writer, (void *)i,
writer_tasks[i]);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
}
torture_init_end();
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index f640cbd..8b410d9 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -1432,28 +1432,34 @@ static void rcutorture_one_extend(int *readstate, int newstate,
/* First, put new protection in place to avoid critical-section gap. */
if (statesnew & RCUTORTURE_RDR_BH)
local_bh_disable();
+ if (statesnew & RCUTORTURE_RDR_RBH)
+ rcu_read_lock_bh();
if (statesnew & RCUTORTURE_RDR_IRQ)
local_irq_disable();
if (statesnew & RCUTORTURE_RDR_PREEMPT)
preempt_disable();
- if (statesnew & RCUTORTURE_RDR_RBH)
- rcu_read_lock_bh();
if (statesnew & RCUTORTURE_RDR_SCHED)
rcu_read_lock_sched();
if (statesnew & RCUTORTURE_RDR_RCU)
idxnew = cur_ops->readlock() << RCUTORTURE_RDR_SHIFT;
- /* Next, remove old protection, irq first due to bh conflict. */
+ /*
+ * Next, remove old protection, in decreasing order of strength
+ * to avoid unlock paths that aren't safe in the stronger
+ * context. Namely: BH can not be enabled with disabled interrupts.
+ * Additionally PREEMPT_RT requires that BH is enabled in preemptible
+ * context.
+ */
if (statesold & RCUTORTURE_RDR_IRQ)
local_irq_enable();
- if (statesold & RCUTORTURE_RDR_BH)
- local_bh_enable();
if (statesold & RCUTORTURE_RDR_PREEMPT)
preempt_enable();
- if (statesold & RCUTORTURE_RDR_RBH)
- rcu_read_unlock_bh();
if (statesold & RCUTORTURE_RDR_SCHED)
rcu_read_unlock_sched();
+ if (statesold & RCUTORTURE_RDR_BH)
+ local_bh_enable();
+ if (statesold & RCUTORTURE_RDR_RBH)
+ rcu_read_unlock_bh();
if (statesold & RCUTORTURE_RDR_RCU) {
bool lockit = !statesnew && !(torture_random(trsp) & 0xffff);
@@ -1496,6 +1502,9 @@ rcutorture_extend_mask(int oldmask, struct torture_random_state *trsp)
int mask = rcutorture_extend_mask_max();
unsigned long randmask1 = torture_random(trsp) >> 8;
unsigned long randmask2 = randmask1 >> 3;
+ unsigned long preempts = RCUTORTURE_RDR_PREEMPT | RCUTORTURE_RDR_SCHED;
+ unsigned long preempts_irq = preempts | RCUTORTURE_RDR_IRQ;
+ unsigned long bhs = RCUTORTURE_RDR_BH | RCUTORTURE_RDR_RBH;
WARN_ON_ONCE(mask >> RCUTORTURE_RDR_SHIFT);
/* Mostly only one bit (need preemption!), sometimes lots of bits. */
@@ -1503,11 +1512,26 @@ rcutorture_extend_mask(int oldmask, struct torture_random_state *trsp)
mask = mask & randmask2;
else
mask = mask & (1 << (randmask2 % RCUTORTURE_RDR_NBITS));
- /* Can't enable bh w/irq disabled. */
- if ((mask & RCUTORTURE_RDR_IRQ) &&
- ((!(mask & RCUTORTURE_RDR_BH) && (oldmask & RCUTORTURE_RDR_BH)) ||
- (!(mask & RCUTORTURE_RDR_RBH) && (oldmask & RCUTORTURE_RDR_RBH))))
- mask |= RCUTORTURE_RDR_BH | RCUTORTURE_RDR_RBH;
+
+ /*
+ * Can't enable bh w/irq disabled.
+ */
+ if (mask & RCUTORTURE_RDR_IRQ)
+ mask |= oldmask & bhs;
+
+ /*
+ * Ideally these sequences would be detected in debug builds
+ * (regardless of RT), but until then don't stop testing
+ * them on non-RT.
+ */
+ if (IS_ENABLED(CONFIG_PREEMPT_RT)) {
+ /* Can't modify BH in atomic context */
+ if (oldmask & preempts_irq)
+ mask &= ~bhs;
+ if ((oldmask | mask) & preempts_irq)
+ mask |= oldmask & bhs;
+ }
+
return mask ?: RCUTORTURE_RDR_RCU;
}
@@ -2741,7 +2765,7 @@ static int rcu_torture_read_exit(void *unused)
static int rcu_torture_read_exit_init(void)
{
if (read_exit_burst <= 0)
- return -EINVAL;
+ return 0;
init_waitqueue_head(&read_exit_wq);
read_exit_child_stop = false;
read_exit_child_stopped = false;
@@ -2819,7 +2843,7 @@ rcu_torture_cleanup(void)
rcutorture_seq_diff(gp_seq, start_gp_seq));
torture_stop_kthread(rcu_torture_stats, stats_task);
torture_stop_kthread(rcu_torture_fqs, fqs_task);
- if (rcu_torture_can_boost())
+ if (rcu_torture_can_boost() && rcutor_hp >= 0)
cpuhp_remove_state(rcutor_hp);
/*
@@ -3037,7 +3061,7 @@ rcu_torture_init(void)
rcu_torture_write_types();
firsterr = torture_create_kthread(rcu_torture_writer, NULL,
writer_task);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
if (nfakewriters > 0) {
fakewriter_tasks = kcalloc(nfakewriters,
@@ -3052,7 +3076,7 @@ rcu_torture_init(void)
for (i = 0; i < nfakewriters; i++) {
firsterr = torture_create_kthread(rcu_torture_fakewriter,
NULL, fakewriter_tasks[i]);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
}
reader_tasks = kcalloc(nrealreaders, sizeof(reader_tasks[0]),
@@ -3068,7 +3092,7 @@ rcu_torture_init(void)
rcu_torture_reader_mbchk[i].rtc_chkrdr = -1;
firsterr = torture_create_kthread(rcu_torture_reader, (void *)i,
reader_tasks[i]);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
}
nrealnocbers = nocbs_nthreads;
@@ -3088,18 +3112,18 @@ rcu_torture_init(void)
}
for (i = 0; i < nrealnocbers; i++) {
firsterr = torture_create_kthread(rcu_nocb_toggle, NULL, nocb_tasks[i]);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
}
if (stat_interval > 0) {
firsterr = torture_create_kthread(rcu_torture_stats, NULL,
stats_task);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
}
if (test_no_idle_hz && shuffle_interval > 0) {
firsterr = torture_shuffle_init(shuffle_interval * HZ);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
}
if (stutter < 0)
@@ -3109,7 +3133,7 @@ rcu_torture_init(void)
t = cur_ops->stall_dur ? cur_ops->stall_dur() : stutter * HZ;
firsterr = torture_stutter_init(stutter * HZ, t);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
}
if (fqs_duration < 0)
@@ -3118,7 +3142,7 @@ rcu_torture_init(void)
/* Create the fqs thread */
firsterr = torture_create_kthread(rcu_torture_fqs, NULL,
fqs_task);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
}
if (test_boost_interval < 1)
@@ -3132,9 +3156,9 @@ rcu_torture_init(void)
firsterr = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "RCU_TORTURE",
rcutorture_booster_init,
rcutorture_booster_cleanup);
- if (firsterr < 0)
- goto unwind;
rcutor_hp = firsterr;
+ if (torture_init_error(firsterr))
+ goto unwind;
// Testing RCU priority boosting requires rcutorture do
// some serious abuse. Counter this by running ksoftirqd
@@ -3153,23 +3177,23 @@ rcu_torture_init(void)
}
shutdown_jiffies = jiffies + shutdown_secs * HZ;
firsterr = torture_shutdown_init(shutdown_secs, rcu_torture_cleanup);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
firsterr = torture_onoff_init(onoff_holdoff * HZ, onoff_interval,
rcutorture_sync);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
firsterr = rcu_torture_stall_init();
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
firsterr = rcu_torture_fwd_prog_init();
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
firsterr = rcu_torture_barrier_init();
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
firsterr = rcu_torture_read_exit_init();
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
if (object_debug)
rcu_test_debug_objects();
diff --git a/kernel/rcu/refscale.c b/kernel/rcu/refscale.c
index 66dc14c..1631ef8 100644
--- a/kernel/rcu/refscale.c
+++ b/kernel/rcu/refscale.c
@@ -824,7 +824,7 @@ ref_scale_init(void)
init_waitqueue_head(&shutdown_wq);
firsterr = torture_create_kthread(ref_scale_shutdown, NULL,
shutdown_task);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
schedule_timeout_uninterruptible(1);
}
@@ -851,7 +851,7 @@ ref_scale_init(void)
for (i = 0; i < nreaders; i++) {
firsterr = torture_create_kthread(ref_scale_reader, (void *)i,
reader_tasks[i].task);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
init_waitqueue_head(&(reader_tasks[i].wq));
@@ -860,7 +860,7 @@ ref_scale_init(void)
// Main Task
init_waitqueue_head(&main_wq);
firsterr = torture_create_kthread(main_func, NULL, main_task);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
torture_init_end();
diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
index 806160c..66e7586 100644
--- a/kernel/rcu/tasks.h
+++ b/kernel/rcu/tasks.h
@@ -197,6 +197,7 @@ static int __noreturn rcu_tasks_kthread(void *arg)
* This loop is terminated by the system going down. ;-)
*/
for (;;) {
+ set_tasks_gp_state(rtp, RTGS_WAIT_CBS);
/* Pick up any new callbacks. */
raw_spin_lock_irqsave(&rtp->cbs_lock, flags);
@@ -236,8 +237,6 @@ static int __noreturn rcu_tasks_kthread(void *arg)
}
/* Paranoid sleep to keep this from entering a tight loop */
schedule_timeout_idle(rtp->gp_sleep);
-
- set_tasks_gp_state(rtp, RTGS_WAIT_CBS);
}
}
@@ -369,7 +368,7 @@ static void rcu_tasks_wait_gp(struct rcu_tasks *rtp)
////////////////////////////////////////////////////////////////////////
//
// Simple variant of RCU whose quiescent states are voluntary context
-// switch, cond_resched_rcu_qs(), user-space execution, and idle.
+// switch, cond_resched_tasks_rcu_qs(), user-space execution, and idle.
// As such, grace periods can take one good long time. There are no
// read-side primitives similar to rcu_read_lock() and rcu_read_unlock()
// because this implementation is intended to get the system into a safe
@@ -540,7 +539,7 @@ DEFINE_RCU_TASKS(rcu_tasks, rcu_tasks_wait_gp, call_rcu_tasks, "RCU Tasks");
* period elapses, in other words after all currently executing RCU
* read-side critical sections have completed. call_rcu_tasks() assumes
* that the read-side critical sections end at a voluntary context
- * switch (not a preemption!), cond_resched_rcu_qs(), entry into idle,
+ * switch (not a preemption!), cond_resched_tasks_rcu_qs(), entry into idle,
* or transition to usermode execution. As such, there are no read-side
* primitives analogous to rcu_read_lock() and rcu_read_unlock() because
* this primitive is intended to determine that all tasks have passed
@@ -678,11 +677,11 @@ DEFINE_RCU_TASKS(rcu_tasks_rude, rcu_tasks_rude_wait_gp, call_rcu_tasks_rude,
* period elapses, in other words after all currently executing RCU
* read-side critical sections have completed. call_rcu_tasks_rude()
* assumes that the read-side critical sections end at context switch,
- * cond_resched_rcu_qs(), or transition to usermode execution. As such,
- * there are no read-side primitives analogous to rcu_read_lock() and
- * rcu_read_unlock() because this primitive is intended to determine
- * that all tasks have passed through a safe state, not so much for
- * data-structure synchronization.
+ * cond_resched_tasks_rcu_qs(), or transition to usermode execution (as
+ * usermode execution is schedulable). As such, there are no read-side
+ * primitives analogous to rcu_read_lock() and rcu_read_unlock() because
+ * this primitive is intended to determine that all tasks have passed
+ * through a safe state, not so much for data-structure synchronization.
*
* See the description of call_rcu() for more detailed information on
* memory ordering guarantees.
@@ -700,8 +699,8 @@ EXPORT_SYMBOL_GPL(call_rcu_tasks_rude);
* grace period has elapsed, in other words after all currently
* executing rcu-tasks read-side critical sections have elapsed. These
* read-side critical sections are delimited by calls to schedule(),
- * cond_resched_tasks_rcu_qs(), userspace execution, and (in theory,
- * anyway) cond_resched().
+ * cond_resched_tasks_rcu_qs(), userspace execution (which is a schedulable
+ * context), and (in theory, anyway) cond_resched().
*
* This is a very specialized primitive, intended only for a few uses in
* tracing and other situations requiring manipulation of function preambles
@@ -758,7 +757,7 @@ EXPORT_SYMBOL_GPL(show_rcu_tasks_rude_gp_kthread);
// 2. Protects code in the idle loop, exception entry/exit, and
// CPU-hotplug code paths, similar to the capabilities of SRCU.
//
-// 3. Avoids expensive read-side instruction, having overhead similar
+// 3. Avoids expensive read-side instructions, having overhead similar
// to that of Preemptible RCU.
//
// There are of course downsides. The grace-period code can send IPIs to
@@ -848,7 +847,7 @@ static void rcu_read_unlock_iw(struct irq_work *iwp)
static DEFINE_IRQ_WORK(rcu_tasks_trace_iw, rcu_read_unlock_iw);
/* If we are the last reader, wake up the grace-period kthread. */
-void rcu_read_unlock_trace_special(struct task_struct *t, int nesting)
+void rcu_read_unlock_trace_special(struct task_struct *t)
{
int nq = READ_ONCE(t->trc_reader_special.b.need_qs);
@@ -858,7 +857,7 @@ void rcu_read_unlock_trace_special(struct task_struct *t, int nesting)
// Update .need_qs before ->trc_reader_nesting for irq/NMI handlers.
if (nq)
WRITE_ONCE(t->trc_reader_special.b.need_qs, false);
- WRITE_ONCE(t->trc_reader_nesting, nesting);
+ WRITE_ONCE(t->trc_reader_nesting, 0);
if (nq && atomic_dec_and_test(&trc_n_readers_need_end))
irq_work_queue(&rcu_tasks_trace_iw);
}
@@ -890,32 +889,24 @@ static void trc_read_check_handler(void *t_in)
// If the task is no longer running on this CPU, leave.
if (unlikely(texp != t)) {
- if (WARN_ON_ONCE(atomic_dec_and_test(&trc_n_readers_need_end)))
- wake_up(&trc_wait);
goto reset_ipi; // Already on holdout list, so will check later.
}
// If the task is not in a read-side critical section, and
// if this is the last reader, awaken the grace-period kthread.
if (likely(!READ_ONCE(t->trc_reader_nesting))) {
- if (WARN_ON_ONCE(atomic_dec_and_test(&trc_n_readers_need_end)))
- wake_up(&trc_wait);
- // Mark as checked after decrement to avoid false
- // positives on the above WARN_ON_ONCE().
WRITE_ONCE(t->trc_reader_checked, true);
goto reset_ipi;
}
// If we are racing with an rcu_read_unlock_trace(), try again later.
- if (unlikely(READ_ONCE(t->trc_reader_nesting) < 0)) {
- if (WARN_ON_ONCE(atomic_dec_and_test(&trc_n_readers_need_end)))
- wake_up(&trc_wait);
+ if (unlikely(READ_ONCE(t->trc_reader_nesting) < 0))
goto reset_ipi;
- }
WRITE_ONCE(t->trc_reader_checked, true);
// Get here if the task is in a read-side critical section. Set
// its state so that it will awaken the grace-period kthread upon
// exit from that critical section.
+ atomic_inc(&trc_n_readers_need_end); // One more to wait on.
WARN_ON_ONCE(READ_ONCE(t->trc_reader_special.b.need_qs));
WRITE_ONCE(t->trc_reader_special.b.need_qs, true);
@@ -931,7 +922,7 @@ static void trc_read_check_handler(void *t_in)
static bool trc_inspect_reader(struct task_struct *t, void *arg)
{
int cpu = task_cpu(t);
- bool in_qs = false;
+ int nesting;
bool ofl = cpu_is_offline(cpu);
if (task_curr(t)) {
@@ -951,18 +942,18 @@ static bool trc_inspect_reader(struct task_struct *t, void *arg)
n_heavy_reader_updates++;
if (ofl)
n_heavy_reader_ofl_updates++;
- in_qs = true;
+ nesting = 0;
} else {
// The task is not running, so C-language access is safe.
- in_qs = likely(!t->trc_reader_nesting);
+ nesting = t->trc_reader_nesting;
}
- // Mark as checked so that the grace-period kthread will
- // remove it from the holdout list.
- t->trc_reader_checked = true;
-
- if (in_qs)
- return true; // Already in quiescent state, done!!!
+ // If not exiting a read-side critical section, mark as checked
+ // so that the grace-period kthread will remove it from the
+ // holdout list.
+ t->trc_reader_checked = nesting >= 0;
+ if (nesting <= 0)
+ return !nesting; // If in QS, done, otherwise try again later.
// The task is in a read-side critical section, so set up its
// state so that it will awaken the grace-period kthread upon exit
@@ -1000,7 +991,7 @@ static void trc_wait_for_one_reader(struct task_struct *t,
// If this task is not yet on the holdout list, then we are in
// an RCU read-side critical section. Otherwise, the invocation of
- // rcu_add_holdout() that added it to the list did the necessary
+ // trc_add_holdout() that added it to the list did the necessary
// get_task_struct(). Either way, the task cannot be freed out
// from under this code.
@@ -1015,21 +1006,17 @@ static void trc_wait_for_one_reader(struct task_struct *t,
if (per_cpu(trc_ipi_to_cpu, cpu) || t->trc_ipi_to_cpu >= 0)
return;
- atomic_inc(&trc_n_readers_need_end);
per_cpu(trc_ipi_to_cpu, cpu) = true;
t->trc_ipi_to_cpu = cpu;
rcu_tasks_trace.n_ipis++;
- if (smp_call_function_single(cpu,
- trc_read_check_handler, t, 0)) {
+ if (smp_call_function_single(cpu, trc_read_check_handler, t, 0)) {
// Just in case there is some other reason for
// failure than the target CPU being offline.
+ WARN_ONCE(1, "%s(): smp_call_function_single() failed for CPU: %d\n",
+ __func__, cpu);
rcu_tasks_trace.n_ipis_fails++;
per_cpu(trc_ipi_to_cpu, cpu) = false;
- t->trc_ipi_to_cpu = cpu;
- if (atomic_dec_and_test(&trc_n_readers_need_end)) {
- WARN_ON_ONCE(1);
- wake_up(&trc_wait);
- }
+ t->trc_ipi_to_cpu = -1;
}
}
}
@@ -1099,9 +1086,9 @@ static void show_stalled_task_trace(struct task_struct *t, bool *firstreport)
cpu = task_cpu(t);
pr_alert("P%d: %c%c%c nesting: %d%c cpu: %d\n",
t->pid,
- ".I"[READ_ONCE(t->trc_ipi_to_cpu) > 0],
+ ".I"[READ_ONCE(t->trc_ipi_to_cpu) >= 0],
".i"[is_idle_task(t)],
- ".N"[cpu > 0 && tick_nohz_full_cpu(cpu)],
+ ".N"[cpu >= 0 && tick_nohz_full_cpu(cpu)],
READ_ONCE(t->trc_reader_nesting),
" N"[!!READ_ONCE(t->trc_reader_special.b.need_qs)],
cpu);
@@ -1144,20 +1131,34 @@ static void check_all_holdout_tasks_trace(struct list_head *hop,
cpus_read_unlock();
if (needreport) {
- if (firstreport)
+ if (*firstreport)
pr_err("INFO: rcu_tasks_trace detected stalls? (Late IPI?)\n");
show_stalled_ipi_trace();
}
}
+static void rcu_tasks_trace_empty_fn(void *unused)
+{
+}
+
/* Wait for grace period to complete and provide ordering. */
static void rcu_tasks_trace_postgp(struct rcu_tasks *rtp)
{
+ int cpu;
bool firstreport;
struct task_struct *g, *t;
LIST_HEAD(holdouts);
long ret;
+ // Wait for any lingering IPI handlers to complete. Note that
+ // if a CPU has gone offline or transitioned to userspace in the
+ // meantime, all IPI handlers should have been drained beforehand.
+ // Yes, this assumes that CPUs process IPIs in order. If that ever
+ // changes, there will need to be a recheck and/or timed wait.
+ for_each_online_cpu(cpu)
+ if (smp_load_acquire(per_cpu_ptr(&trc_ipi_to_cpu, cpu)))
+ smp_call_function_single(cpu, rcu_tasks_trace_empty_fn, NULL, 1);
+
// Remove the safety count.
smp_mb__before_atomic(); // Order vs. earlier atomics
atomic_dec(&trc_n_readers_need_end);
@@ -1200,7 +1201,7 @@ static void exit_tasks_rcu_finish_trace(struct task_struct *t)
WARN_ON_ONCE(READ_ONCE(t->trc_reader_nesting));
WRITE_ONCE(t->trc_reader_nesting, 0);
if (WARN_ON_ONCE(READ_ONCE(t->trc_reader_special.b.need_qs)))
- rcu_read_unlock_trace_special(t, 0);
+ rcu_read_unlock_trace_special(t);
}
/**
@@ -1208,15 +1209,11 @@ static void exit_tasks_rcu_finish_trace(struct task_struct *t)
* @rhp: structure to be used for queueing the RCU updates.
* @func: actual callback function to be invoked after the grace period
*
- * The callback function will be invoked some time after a full grace
- * period elapses, in other words after all currently executing RCU
- * read-side critical sections have completed. call_rcu_tasks_trace()
- * assumes that the read-side critical sections end at context switch,
- * cond_resched_rcu_qs(), or transition to usermode execution. As such,
- * there are no read-side primitives analogous to rcu_read_lock() and
- * rcu_read_unlock() because this primitive is intended to determine
- * that all tasks have passed through a safe state, not so much for
- * data-structure synchronization.
+ * The callback function will be invoked some time after a trace rcu-tasks
+ * grace period elapses, in other words after all currently executing
+ * trace rcu-tasks read-side critical sections have completed. These
+ * read-side critical sections are delimited by calls to rcu_read_lock_trace()
+ * and rcu_read_unlock_trace().
*
* See the description of call_rcu() for more detailed information on
* memory ordering guarantees.
@@ -1232,7 +1229,7 @@ EXPORT_SYMBOL_GPL(call_rcu_tasks_trace);
*
* Control will return to the caller some time after a trace rcu-tasks
* grace period has elapsed, in other words after all currently executing
- * rcu-tasks read-side critical sections have elapsed. These read-side
+ * trace rcu-tasks read-side critical sections have elapsed. These read-side
* critical sections are delimited by calls to rcu_read_lock_trace()
* and rcu_read_unlock_trace().
*
diff --git a/kernel/scftorture.c b/kernel/scftorture.c
index 64a0828..5d42f44 100644
--- a/kernel/scftorture.c
+++ b/kernel/scftorture.c
@@ -341,6 +341,7 @@ static void scftorture_invoke_one(struct scf_statistics *scfp, struct torture_ra
cpu = torture_random(trsp) % nr_cpu_ids;
scfp->n_resched++;
resched_cpu(cpu);
+ this_cpu_inc(scf_invoked_count);
}
break;
case SCF_PRIM_SINGLE:
@@ -553,18 +554,18 @@ static int __init scf_torture_init(void)
scftorture_print_module_parms("Start of test");
- if (weight_resched == -1 &&
- weight_single == -1 && weight_single_rpc == -1 && weight_single_wait == -1 &&
- weight_many == -1 && weight_many_wait == -1 &&
- weight_all == -1 && weight_all_wait == -1) {
- weight_resched1 = 2 * nr_cpu_ids;
- weight_single1 = 2 * nr_cpu_ids;
- weight_single_rpc1 = 2 * nr_cpu_ids;
- weight_single_wait1 = 2 * nr_cpu_ids;
- weight_many1 = 2;
- weight_many_wait1 = 2;
- weight_all1 = 1;
- weight_all_wait1 = 1;
+ if (weight_resched <= 0 &&
+ weight_single <= 0 && weight_single_rpc <= 0 && weight_single_wait <= 0 &&
+ weight_many <= 0 && weight_many_wait <= 0 &&
+ weight_all <= 0 && weight_all_wait <= 0) {
+ weight_resched1 = weight_resched == 0 ? 0 : 2 * nr_cpu_ids;
+ weight_single1 = weight_single == 0 ? 0 : 2 * nr_cpu_ids;
+ weight_single_rpc1 = weight_single_rpc == 0 ? 0 : 2 * nr_cpu_ids;
+ weight_single_wait1 = weight_single_wait == 0 ? 0 : 2 * nr_cpu_ids;
+ weight_many1 = weight_many == 0 ? 0 : 2;
+ weight_many_wait1 = weight_many_wait == 0 ? 0 : 2;
+ weight_all1 = weight_all == 0 ? 0 : 1;
+ weight_all_wait1 = weight_all_wait == 0 ? 0 : 1;
} else {
if (weight_resched == -1)
weight_resched1 = 0;
@@ -583,8 +584,8 @@ static int __init scf_torture_init(void)
if (weight_all_wait == -1)
weight_all_wait1 = 0;
}
- if (weight_single1 == 0 && weight_single_rpc1 == 0 && weight_single_wait1 == 0 &&
- weight_many1 == 0 && weight_many_wait1 == 0 &&
+ if (weight_resched1 == 0 && weight_single1 == 0 && weight_single_rpc1 == 0 &&
+ weight_single_wait1 == 0 && weight_many1 == 0 && weight_many_wait1 == 0 &&
weight_all1 == 0 && weight_all_wait1 == 0) {
VERBOSE_SCFTORTOUT_ERRSTRING("all zero weights makes no sense");
firsterr = -EINVAL;
@@ -605,17 +606,17 @@ static int __init scf_torture_init(void)
if (onoff_interval > 0) {
firsterr = torture_onoff_init(onoff_holdoff * HZ, onoff_interval, NULL);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
}
if (shutdown_secs > 0) {
firsterr = torture_shutdown_init(shutdown_secs, scf_torture_cleanup);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
}
if (stutter > 0) {
firsterr = torture_stutter_init(stutter, stutter);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
}
@@ -636,12 +637,12 @@ static int __init scf_torture_init(void)
scf_stats_p[i].cpu = i;
firsterr = torture_create_kthread(scftorture_invoker, (void *)&scf_stats_p[i],
scf_stats_p[i].task);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
}
if (stat_interval > 0) {
firsterr = torture_create_kthread(scf_torture_stats, NULL, scf_torture_stats_task);
- if (firsterr)
+ if (torture_init_error(firsterr))
goto unwind;
}
@@ -651,6 +652,10 @@ static int __init scf_torture_init(void)
unwind:
torture_init_end();
scf_torture_cleanup();
+ if (shutdown_secs) {
+ WARN_ON(!IS_MODULE(CONFIG_SCF_TORTURE_TEST));
+ kernel_power_off();
+ }
return firsterr;
}
diff --git a/tools/rcu/extract-stall.sh b/tools/rcu/extract-stall.sh
new file mode 100644
index 0000000..e565697
--- /dev/null
+++ b/tools/rcu/extract-stall.sh
@@ -0,0 +1,34 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Extract any RCU CPU stall warnings present in specified file.
+# Filter out clocksource lines. Note that preceding-lines excludes the
+# initial line of the stall warning but trailing-lines includes it.
+#
+# Usage: extract-stall.sh dmesg-file [ preceding-lines [ trailing-lines ] ]
+
+echo $1
+preceding_lines="${2-3}"
+trailing_lines="${3-10}"
+
+awk -v preceding_lines="$preceding_lines" -v trailing_lines="$trailing_lines" '
+suffix <= 0 {
+ for (i = preceding_lines; i > 0; i--)
+ last[i] = last[i - 1];
+ last[0] = $0;
+}
+
+suffix > 0 {
+ print $0;
+ suffix--;
+ if (suffix <= 0)
+ print "";
+}
+
+suffix <= 0 && /detected stall/ {
+ for (i = preceding_lines; i >= 0; i--)
+ if (last[i] != "")
+ print last[i];
+ suffix = trailing_lines;
+}' < "$1" | tr -d '\015' | grep -v clocksource
+
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-remote.sh b/tools/testing/selftests/rcutorture/bin/kvm-remote.sh
index 03126eb..c7d42ef 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-remote.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-remote.sh
@@ -149,6 +149,7 @@
done
# Download and expand the tarball on all systems.
+echo Build-products tarball: `du -h $T/binres.tgz` | tee -a "$oldrun/remote-log"
for i in $systems
do
echo Downloading tarball to $i `date` | tee -a "$oldrun/remote-log"
diff --git a/tools/testing/selftests/rcutorture/bin/kvm.sh b/tools/testing/selftests/rcutorture/bin/kvm.sh
index f442d84..6cf9ec6 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm.sh
@@ -184,7 +184,7 @@
TORTURE_KCONFIG_KASAN_ARG="CONFIG_DEBUG_INFO=y CONFIG_KASAN=y"; export TORTURE_KCONFIG_KASAN_ARG
;;
--kcsan)
- TORTURE_KCONFIG_KCSAN_ARG="CONFIG_DEBUG_INFO=y CONFIG_KCSAN=y CONFIG_KCSAN_ASSUME_PLAIN_WRITES_ATOMIC=n CONFIG_KCSAN_REPORT_VALUE_CHANGE_ONLY=n CONFIG_KCSAN_REPORT_ONCE_IN_MS=100000 CONFIG_KCSAN_INTERRUPT_WATCHER=y CONFIG_KCSAN_VERBOSE=y CONFIG_DEBUG_LOCK_ALLOC=y CONFIG_PROVE_LOCKING=y"; export TORTURE_KCONFIG_KCSAN_ARG
+ TORTURE_KCONFIG_KCSAN_ARG="CONFIG_DEBUG_INFO=y CONFIG_KCSAN=y CONFIG_KCSAN_STRICT=y CONFIG_KCSAN_REPORT_ONCE_IN_MS=100000 CONFIG_KCSAN_VERBOSE=y CONFIG_DEBUG_LOCK_ALLOC=y CONFIG_PROVE_LOCKING=y"; export TORTURE_KCONFIG_KCSAN_ARG
;;
--kmake-arg|--kmake-args)
checkarg --kmake-arg "(kernel make arguments)" $# "$2" '.*' '^error$'
diff --git a/tools/testing/selftests/rcutorture/bin/torture.sh b/tools/testing/selftests/rcutorture/bin/torture.sh
index 363f560..eae88aa 100755
--- a/tools/testing/selftests/rcutorture/bin/torture.sh
+++ b/tools/testing/selftests/rcutorture/bin/torture.sh
@@ -351,7 +351,7 @@
if test "$do_scftorture" = "yes"
then
torture_bootargs="scftorture.nthreads=$HALF_ALLOTED_CPUS torture.disable_onoff_at_boot"
- torture_set "scftorture" tools/testing/selftests/rcutorture/bin/kvm.sh --torture scf --allcpus --duration "$duration_scftorture" --configs "$configs_scftorture" --kconfig "CONFIG_NR_CPUS=$HALF_ALLOTED_CPUS" --trust-make
+ torture_set "scftorture" tools/testing/selftests/rcutorture/bin/kvm.sh --torture scf --allcpus --duration "$duration_scftorture" --configs "$configs_scftorture" --kconfig "CONFIG_NR_CPUS=$HALF_ALLOTED_CPUS" --memory 1G --trust-make
fi
if test "$do_refscale" = yes
@@ -434,7 +434,12 @@
batchno=1
if test -s $T/xz-todo
then
- echo Size before compressing: `du -sh $tdir | awk '{ print $1 }'` `date` 2>&1 | tee -a "$tdir/log-xz" | tee -a $T/log
+ for i in `cat $T/xz-todo`
+ do
+ find $i -name 'vmlinux*' -print
+ done | wc -l | awk '{ print $1 }' > $T/xz-todo-count
+ n2compress="`cat $T/xz-todo-count`"
+ echo Size before compressing $n2compress files: `du -sh $tdir | awk '{ print $1 }'` `date` 2>&1 | tee -a "$tdir/log-xz" | tee -a $T/log
for i in `cat $T/xz-todo`
do
echo Compressing vmlinux files in ${i}: `date` >> "$tdir/log-xz" 2>&1
@@ -456,7 +461,7 @@
echo Waiting for final batch $batchno of $ncompresses compressions `date` | tee -a "$tdir/log-xz" | tee -a $T/log
fi
wait
- echo Size after compressing: `du -sh $tdir | awk '{ print $1 }'` `date` 2>&1 | tee -a "$tdir/log-xz" | tee -a $T/log
+ echo Size after compressing $n2compress files: `du -sh $tdir | awk '{ print $1 }'` `date` 2>&1 | tee -a "$tdir/log-xz" | tee -a $T/log
echo Total duration `get_starttime_duration $starttime`. | tee -a $T/log
else
echo No compression needed: `date` >> "$tdir/log-xz" 2>&1
