Merge tag 'rcu.2022.03.13a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
Pull RCU updates from Paul McKenney:
- Fix idle detection (Neeraj Upadhyay) and missing access marking
detected by KCSAN.
- Reduce coupling between rcu_barrier() and CPU-hotplug operations, so
that rcu_barrier() no longer needs to do cpus_read_lock(). This may
also someday allow system boot to bring CPUs online concurrently.
- Enable more aggressive movement to per-CPU queueing when reacting to
excessive lock contention due to workloads placing heavy update-side
stress on RCU tasks.
- Improvements to RCU priority boosting, including changes from Neeraj
Upadhyay, Zqiang, and Alison Chaiken.
- Various fixes improving test robustness and debug information.
- Add tests for SRCU size transitions, further compress torture.sh
build products, and improve debug output.
- Miscellaneous fixes.
* tag 'rcu.2022.03.13a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (49 commits)
rcu: Replace cpumask_weight with cpumask_empty where appropriate
rcu: Remove __read_mostly annotations from rcu_scheduler_active externs
rcu: Uninline multi-use function: finish_rcuwait()
rcu: Mark writes to the rcu_segcblist structure's ->flags field
kasan: Record work creation stack trace with interrupts enabled
rcu: Inline __call_rcu() into call_rcu()
rcu: Add mutex for rcu boost kthread spawning and affinity setting
rcu: Fix description of kvfree_rcu()
MAINTAINERS: Add Frederic and Neeraj to their RCU files
rcutorture: Provide non-power-of-two Tasks RCU scenarios
rcutorture: Test SRCU size transitions
torture: Make torture.sh help message match reality
rcu-tasks: Set ->percpu_enqueue_shift to zero upon contention
rcu-tasks: Use order_base_2() instead of ilog2()
rcu: Create and use an rcu_rdp_cpu_online()
rcu: Make rcu_barrier() no longer block CPU-hotplug operations
rcu: Rework rcu_barrier() and callback-migration logic
rcu: Refactor rcu_barrier() empty-list handling
rcu: Kill rnp->ofl_seq and use only rcu_state.ofl_lock for exclusion
torture: Change KVM environment variable to RCUTORTURE
...
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 7123524..98fa63d 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4504,6 +4504,8 @@
(the least-favored priority). Otherwise, when
RCU_BOOST is not set, valid values are 0-99 and
the default is zero (non-realtime operation).
+ When RCU_NOCB_CPU is set, also adjust the
+ priority of NOCB callback kthreads.
rcutree.rcu_nocb_gp_stride= [KNL]
Set the number of NOCB callback kthreads in
diff --git a/MAINTAINERS b/MAINTAINERS
index 0bbdd40..6376b02 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16324,6 +16324,8 @@
READ-COPY UPDATE (RCU)
M: "Paul E. McKenney" <paulmck@kernel.org>
+M: Frederic Weisbecker <frederic@kernel.org> (kernel/rcu/tree_nocb.h)
+M: Neeraj Upadhyay <quic_neeraju@quicinc.com> (kernel/rcu/tasks.h)
M: Josh Triplett <josh@joshtriplett.org>
R: Steven Rostedt <rostedt@goodmis.org>
R: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 88b42eb..e7c39c2 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -84,7 +84,7 @@ static inline int rcu_preempt_depth(void)
/* Internal to kernel */
void rcu_init(void);
-extern int rcu_scheduler_active __read_mostly;
+extern int rcu_scheduler_active;
void rcu_sched_clock_irq(int user);
void rcu_report_dead(unsigned int cpu);
void rcutree_migrate_callbacks(int cpu);
@@ -924,7 +924,7 @@ static inline notrace void rcu_read_unlock_sched_notrace(void)
*
* kvfree_rcu(ptr);
*
- * where @ptr is a pointer to kvfree().
+ * where @ptr is the pointer to be freed by kvfree().
*
* Please note, head-less way of freeing is permitted to
* use from a context that has to follow might_sleep()
diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h
index 6cc9129..9c6cfb7 100644
--- a/include/linux/rcutree.h
+++ b/include/linux/rcutree.h
@@ -62,7 +62,7 @@ static inline void rcu_irq_exit_check_preempt(void) { }
void exit_rcu(void);
void rcu_scheduler_starting(void);
-extern int rcu_scheduler_active __read_mostly;
+extern int rcu_scheduler_active;
void rcu_end_inkernel_boot(void);
bool rcu_inkernel_boot_has_ended(void);
bool rcu_is_watching(void);
diff --git a/include/linux/rcuwait.h b/include/linux/rcuwait.h
index 61c56cc..8052d34d 100644
--- a/include/linux/rcuwait.h
+++ b/include/linux/rcuwait.h
@@ -47,11 +47,7 @@ static inline void prepare_to_rcuwait(struct rcuwait *w)
rcu_assign_pointer(w->task, current);
}
-static inline void finish_rcuwait(struct rcuwait *w)
-{
- rcu_assign_pointer(w->task, NULL);
- __set_current_state(TASK_RUNNING);
-}
+extern void finish_rcuwait(struct rcuwait *w);
#define rcuwait_wait_event(w, condition, state) \
({ \
diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h
index 670e417..90b2fb0 100644
--- a/include/trace/events/rcu.h
+++ b/include/trace/events/rcu.h
@@ -794,16 +794,15 @@ TRACE_EVENT_RCU(rcu_torture_read,
* Tracepoint for rcu_barrier() execution. The string "s" describes
* the rcu_barrier phase:
* "Begin": rcu_barrier() started.
+ * "CB": An rcu_barrier_callback() invoked a callback, not the last.
* "EarlyExit": rcu_barrier() piggybacked, thus early exit.
* "Inc1": rcu_barrier() piggyback check counter incremented.
- * "OfflineNoCBQ": rcu_barrier() found offline no-CBs CPU with callbacks.
- * "OnlineQ": rcu_barrier() found online CPU with callbacks.
- * "OnlineNQ": rcu_barrier() found online CPU, no callbacks.
+ * "Inc2": rcu_barrier() piggyback check counter incremented.
* "IRQ": An rcu_barrier_callback() callback posted on remote CPU.
* "IRQNQ": An rcu_barrier_callback() callback found no callbacks.
- * "CB": An rcu_barrier_callback() invoked a callback, not the last.
* "LastCB": An rcu_barrier_callback() invoked the last callback.
- * "Inc2": rcu_barrier() piggyback check counter incremented.
+ * "NQ": rcu_barrier() found a CPU with no callbacks.
+ * "OnlineQ": rcu_barrier() found online CPU with callbacks.
* The "cpu" argument is the CPU or -1 if meaningless, the "cnt" argument
* is the count of remaining callbacks, and "done" is the piggybacking count.
*/
diff --git a/kernel/rcu/rcu_segcblist.h b/kernel/rcu/rcu_segcblist.h
index e373fbe..431cee2 100644
--- a/kernel/rcu/rcu_segcblist.h
+++ b/kernel/rcu/rcu_segcblist.h
@@ -56,13 +56,13 @@ static inline long rcu_segcblist_n_cbs(struct rcu_segcblist *rsclp)
static inline void rcu_segcblist_set_flags(struct rcu_segcblist *rsclp,
int flags)
{
- rsclp->flags |= flags;
+ WRITE_ONCE(rsclp->flags, rsclp->flags | flags);
}
static inline void rcu_segcblist_clear_flags(struct rcu_segcblist *rsclp,
int flags)
{
- rsclp->flags &= ~flags;
+ WRITE_ONCE(rsclp->flags, rsclp->flags & ~flags);
}
static inline bool rcu_segcblist_test_flags(struct rcu_segcblist *rsclp,
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 422f7e4..55d049c 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -284,7 +284,7 @@ static atomic_t barrier_cbs_invoked; /* Barrier callbacks invoked. */
static wait_queue_head_t *barrier_cbs_wq; /* Coordinate barrier testing. */
static DECLARE_WAIT_QUEUE_HEAD(barrier_wq);
-static bool rcu_fwd_cb_nodelay; /* Short rcu_torture_delay() delays. */
+static atomic_t rcu_fwd_cb_nodelay; /* Short rcu_torture_delay() delays. */
/*
* Allocate an element from the rcu_tortures pool.
@@ -387,7 +387,7 @@ rcu_read_delay(struct torture_random_state *rrsp, struct rt_read_seg *rtrsp)
* period, and we want a long delay occasionally to trigger
* force_quiescent_state. */
- if (!READ_ONCE(rcu_fwd_cb_nodelay) &&
+ if (!atomic_read(&rcu_fwd_cb_nodelay) &&
!(torture_random(rrsp) % (nrealreaders * 2000 * longdelay_ms))) {
started = cur_ops->get_gp_seq();
ts = rcu_trace_clock_local();
@@ -674,6 +674,7 @@ static struct rcu_torture_ops srcu_ops = {
.call = srcu_torture_call,
.cb_barrier = srcu_torture_barrier,
.stats = srcu_torture_stats,
+ .cbflood_max = 50000,
.irq_capable = 1,
.no_pi_lock = IS_ENABLED(CONFIG_TINY_SRCU),
.name = "srcu"
@@ -708,6 +709,7 @@ static struct rcu_torture_ops srcud_ops = {
.call = srcu_torture_call,
.cb_barrier = srcu_torture_barrier,
.stats = srcu_torture_stats,
+ .cbflood_max = 50000,
.irq_capable = 1,
.no_pi_lock = IS_ENABLED(CONFIG_TINY_SRCU),
.name = "srcud"
@@ -997,7 +999,7 @@ static int rcu_torture_boost(void *arg)
goto checkwait;
/* Wait for the next test interval. */
- oldstarttime = boost_starttime;
+ oldstarttime = READ_ONCE(boost_starttime);
while (time_before(jiffies, oldstarttime)) {
schedule_timeout_interruptible(oldstarttime - jiffies);
if (stutter_wait("rcu_torture_boost"))
@@ -1041,10 +1043,11 @@ static int rcu_torture_boost(void *arg)
* interval. Besides, we are running at RT priority,
* so delays should be relatively rare.
*/
- while (oldstarttime == boost_starttime && !kthread_should_stop()) {
+ while (oldstarttime == READ_ONCE(boost_starttime) && !kthread_should_stop()) {
if (mutex_trylock(&boost_mutex)) {
if (oldstarttime == boost_starttime) {
- boost_starttime = jiffies + test_boost_interval * HZ;
+ WRITE_ONCE(boost_starttime,
+ jiffies + test_boost_interval * HZ);
n_rcu_torture_boosts++;
}
mutex_unlock(&boost_mutex);
@@ -1276,7 +1279,7 @@ rcu_torture_writer(void *arg)
boot_ended = rcu_inkernel_boot_has_ended();
stutter_waited = stutter_wait("rcu_torture_writer");
if (stutter_waited &&
- !READ_ONCE(rcu_fwd_cb_nodelay) &&
+ !atomic_read(&rcu_fwd_cb_nodelay) &&
!cur_ops->slow_gps &&
!torture_must_stop() &&
boot_ended)
@@ -2180,7 +2183,6 @@ static void rcu_torture_fwd_cb_hist(struct rcu_fwd *rfp)
for (i = ARRAY_SIZE(rfp->n_launders_hist) - 1; i > 0; i--)
if (rfp->n_launders_hist[i].n_launders > 0)
break;
- mutex_lock(&rcu_fwd_mutex); // Serialize histograms.
pr_alert("%s: Callback-invocation histogram %d (duration %lu jiffies):",
__func__, rfp->rcu_fwd_id, jiffies - rfp->rcu_fwd_startat);
gps_old = rfp->rcu_launder_gp_seq_start;
@@ -2193,7 +2195,6 @@ static void rcu_torture_fwd_cb_hist(struct rcu_fwd *rfp)
gps_old = gps;
}
pr_cont("\n");
- mutex_unlock(&rcu_fwd_mutex);
}
/* Callback function for continuous-flood RCU callbacks. */
@@ -2281,6 +2282,7 @@ static void rcu_torture_fwd_prog_nr(struct rcu_fwd *rfp,
unsigned long stopat;
static DEFINE_TORTURE_RANDOM(trs);
+ pr_alert("%s: Starting forward-progress test %d\n", __func__, rfp->rcu_fwd_id);
if (!cur_ops->sync)
return; // Cannot do need_resched() forward progress testing without ->sync.
if (cur_ops->call && cur_ops->cb_barrier) {
@@ -2289,7 +2291,7 @@ static void rcu_torture_fwd_prog_nr(struct rcu_fwd *rfp,
}
/* Tight loop containing cond_resched(). */
- WRITE_ONCE(rcu_fwd_cb_nodelay, true);
+ atomic_inc(&rcu_fwd_cb_nodelay);
cur_ops->sync(); /* Later readers see above write. */
if (selfpropcb) {
WRITE_ONCE(fcs.stop, 0);
@@ -2325,6 +2327,7 @@ static void rcu_torture_fwd_prog_nr(struct rcu_fwd *rfp,
if (selfpropcb) {
WRITE_ONCE(fcs.stop, 1);
cur_ops->sync(); /* Wait for running CB to complete. */
+ pr_alert("%s: Waiting for CBs: %pS() %d\n", __func__, cur_ops->cb_barrier, rfp->rcu_fwd_id);
cur_ops->cb_barrier(); /* Wait for queued callbacks. */
}
@@ -2333,7 +2336,7 @@ static void rcu_torture_fwd_prog_nr(struct rcu_fwd *rfp,
destroy_rcu_head_on_stack(&fcs.rh);
}
schedule_timeout_uninterruptible(HZ / 10); /* Let kthreads recover. */
- WRITE_ONCE(rcu_fwd_cb_nodelay, false);
+ atomic_dec(&rcu_fwd_cb_nodelay);
}
/* Carry out call_rcu() forward-progress testing. */
@@ -2353,13 +2356,14 @@ static void rcu_torture_fwd_prog_cr(struct rcu_fwd *rfp)
unsigned long stopat;
unsigned long stoppedat;
+ pr_alert("%s: Starting forward-progress test %d\n", __func__, rfp->rcu_fwd_id);
if (READ_ONCE(rcu_fwd_emergency_stop))
return; /* Get out of the way quickly, no GP wait! */
if (!cur_ops->call)
return; /* Can't do call_rcu() fwd prog without ->call. */
/* Loop continuously posting RCU callbacks. */
- WRITE_ONCE(rcu_fwd_cb_nodelay, true);
+ atomic_inc(&rcu_fwd_cb_nodelay);
cur_ops->sync(); /* Later readers see above write. */
WRITE_ONCE(rfp->rcu_fwd_startat, jiffies);
stopat = rfp->rcu_fwd_startat + MAX_FWD_CB_JIFFIES;
@@ -2414,6 +2418,7 @@ static void rcu_torture_fwd_prog_cr(struct rcu_fwd *rfp)
n_launders_cb_snap = READ_ONCE(rfp->n_launders_cb);
cver = READ_ONCE(rcu_torture_current_version) - cver;
gps = rcutorture_seq_diff(cur_ops->get_gp_seq(), gps);
+ pr_alert("%s: Waiting for CBs: %pS() %d\n", __func__, cur_ops->cb_barrier, rfp->rcu_fwd_id);
cur_ops->cb_barrier(); /* Wait for callbacks to be invoked. */
(void)rcu_torture_fwd_prog_cbfree(rfp);
@@ -2427,11 +2432,13 @@ static void rcu_torture_fwd_prog_cr(struct rcu_fwd *rfp)
n_launders, n_launders_sa,
n_max_gps, n_max_cbs, cver, gps);
atomic_long_add(n_max_cbs, &rcu_fwd_max_cbs);
+ mutex_lock(&rcu_fwd_mutex); // Serialize histograms.
rcu_torture_fwd_cb_hist(rfp);
+ mutex_unlock(&rcu_fwd_mutex);
}
schedule_timeout_uninterruptible(HZ); /* Let CBs drain. */
tick_dep_clear_task(current, TICK_DEP_BIT_RCU);
- WRITE_ONCE(rcu_fwd_cb_nodelay, false);
+ atomic_dec(&rcu_fwd_cb_nodelay);
}
@@ -2511,7 +2518,7 @@ static int rcu_torture_fwd_prog(void *args)
firsttime = false;
WRITE_ONCE(rcu_fwd_seq, rcu_fwd_seq + 1);
} else {
- while (READ_ONCE(rcu_fwd_seq) == oldseq)
+ while (READ_ONCE(rcu_fwd_seq) == oldseq && !torture_must_stop())
schedule_timeout_interruptible(1);
oldseq = READ_ONCE(rcu_fwd_seq);
}
@@ -2905,8 +2912,10 @@ rcu_torture_cleanup(void)
int i;
if (torture_cleanup_begin()) {
- if (cur_ops->cb_barrier != NULL)
+ if (cur_ops->cb_barrier != NULL) {
+ pr_info("%s: Invoking %pS().\n", __func__, cur_ops->cb_barrier);
cur_ops->cb_barrier();
+ }
return;
}
if (!cur_ops) {
@@ -2961,8 +2970,10 @@ rcu_torture_cleanup(void)
* Wait for all RCU callbacks to fire, then do torture-type-specific
* cleanup operations.
*/
- if (cur_ops->cb_barrier != NULL)
+ if (cur_ops->cb_barrier != NULL) {
+ pr_info("%s: Invoking %pS().\n", __func__, cur_ops->cb_barrier);
cur_ops->cb_barrier();
+ }
if (cur_ops->cleanup != NULL)
cur_ops->cleanup();
diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
index d64f0b1..ac17348 100644
--- a/kernel/rcu/tasks.h
+++ b/kernel/rcu/tasks.h
@@ -123,7 +123,7 @@ static struct rcu_tasks rt_name = \
.call_func = call, \
.rtpcpu = &rt_name ## __percpu, \
.name = n, \
- .percpu_enqueue_shift = ilog2(CONFIG_NR_CPUS) + 1, \
+ .percpu_enqueue_shift = order_base_2(CONFIG_NR_CPUS), \
.percpu_enqueue_lim = 1, \
.percpu_dequeue_lim = 1, \
.barrier_q_mutex = __MUTEX_INITIALIZER(rt_name.barrier_q_mutex), \
@@ -302,7 +302,7 @@ static void call_rcu_tasks_generic(struct rcu_head *rhp, rcu_callback_t func,
if (unlikely(needadjust)) {
raw_spin_lock_irqsave(&rtp->cbs_gbl_lock, flags);
if (rtp->percpu_enqueue_lim != nr_cpu_ids) {
- WRITE_ONCE(rtp->percpu_enqueue_shift, ilog2(nr_cpu_ids) + 1);
+ WRITE_ONCE(rtp->percpu_enqueue_shift, 0);
WRITE_ONCE(rtp->percpu_dequeue_lim, nr_cpu_ids);
smp_store_release(&rtp->percpu_enqueue_lim, nr_cpu_ids);
pr_info("Switching %s to per-CPU callback queuing.\n", rtp->name);
@@ -417,7 +417,7 @@ static int rcu_tasks_need_gpcb(struct rcu_tasks *rtp)
if (rcu_task_cb_adjust && ncbs <= rcu_task_collapse_lim) {
raw_spin_lock_irqsave(&rtp->cbs_gbl_lock, flags);
if (rtp->percpu_enqueue_lim > 1) {
- WRITE_ONCE(rtp->percpu_enqueue_shift, ilog2(nr_cpu_ids) + 1);
+ WRITE_ONCE(rtp->percpu_enqueue_shift, order_base_2(nr_cpu_ids));
smp_store_release(&rtp->percpu_enqueue_lim, 1);
rtp->percpu_dequeue_gpseq = get_state_synchronize_rcu();
pr_info("Starting switch %s to CPU-0 callback queuing.\n", rtp->name);
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 80faf22..a4b8189 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -87,11 +87,12 @@ static struct rcu_state rcu_state = {
.gp_state = RCU_GP_IDLE,
.gp_seq = (0UL - 300UL) << RCU_SEQ_CTR_SHIFT,
.barrier_mutex = __MUTEX_INITIALIZER(rcu_state.barrier_mutex),
+ .barrier_lock = __RAW_SPIN_LOCK_UNLOCKED(rcu_state.barrier_lock),
.name = RCU_NAME,
.abbr = RCU_ABBR,
.exp_mutex = __MUTEX_INITIALIZER(rcu_state.exp_mutex),
.exp_wake_mutex = __MUTEX_INITIALIZER(rcu_state.exp_wake_mutex),
- .ofl_lock = __RAW_SPIN_LOCK_UNLOCKED(rcu_state.ofl_lock),
+ .ofl_lock = __ARCH_SPIN_LOCK_UNLOCKED,
};
/* Dump rcu_node combining tree at boot to verify correct setup. */
@@ -153,7 +154,7 @@ static void sync_sched_exp_online_cleanup(int cpu);
static void check_cb_ovld_locked(struct rcu_data *rdp, struct rcu_node *rnp);
static bool rcu_rdp_is_offloaded(struct rcu_data *rdp);
-/* rcuc/rcub kthread realtime priority */
+/* rcuc/rcub/rcuop kthread realtime priority */
static int kthread_prio = IS_ENABLED(CONFIG_RCU_BOOST) ? 1 : 0;
module_param(kthread_prio, int, 0444);
@@ -222,6 +223,16 @@ static unsigned long rcu_rnp_online_cpus(struct rcu_node *rnp)
}
/*
+ * Is the CPU corresponding to the specified rcu_data structure online
+ * from RCU's perspective? This perspective is given by that structure's
+ * ->qsmaskinitnext field rather than by the global cpu_online_mask.
+ */
+static bool rcu_rdp_cpu_online(struct rcu_data *rdp)
+{
+ return !!(rdp->grpmask & rcu_rnp_online_cpus(rdp->mynode));
+}
+
+/*
* Return true if an RCU grace period is in progress. The READ_ONCE()s
* permit this function to be invoked without holding the root rcu_node
* structure's ->lock, but of course results can be subject to change.
@@ -1166,15 +1177,20 @@ void rcu_request_urgent_qs_task(struct task_struct *t)
bool rcu_lockdep_current_cpu_online(void)
{
struct rcu_data *rdp;
- struct rcu_node *rnp;
bool ret = false;
if (in_nmi() || !rcu_scheduler_fully_active)
return true;
preempt_disable_notrace();
rdp = this_cpu_ptr(&rcu_data);
- rnp = rdp->mynode;
- if (rdp->grpmask & rcu_rnp_online_cpus(rnp) || READ_ONCE(rnp->ofl_seq) & 0x1)
+ /*
+ * Strictly, we care here about the case where the current CPU is
+ * in rcu_cpu_starting() and thus has an excuse for rdp->grpmask
+ * not being up to date. So arch_spin_is_locked() might have a
+ * false positive if it's held by some *other* CPU, but that's
+ * OK because that just means a false *negative* on the warning.
+ */
+ if (rcu_rdp_cpu_online(rdp) || arch_spin_is_locked(&rcu_state.ofl_lock))
ret = true;
preempt_enable_notrace();
return ret;
@@ -1259,8 +1275,7 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp)
* For more detail, please refer to the "Hotplug CPU" section
* of RCU's Requirements documentation.
*/
- if (WARN_ON_ONCE(!(rdp->grpmask & rcu_rnp_online_cpus(rnp)))) {
- bool onl;
+ if (WARN_ON_ONCE(!rcu_rdp_cpu_online(rdp))) {
struct rcu_node *rnp1;
pr_info("%s: grp: %d-%d level: %d ->gp_seq %ld ->completedqs %ld\n",
@@ -1269,9 +1284,8 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp)
for (rnp1 = rnp; rnp1; rnp1 = rnp1->parent)
pr_info("%s: %d:%d ->qsmask %#lx ->qsmaskinit %#lx ->qsmaskinitnext %#lx ->rcu_gp_init_mask %#lx\n",
__func__, rnp1->grplo, rnp1->grphi, rnp1->qsmask, rnp1->qsmaskinit, rnp1->qsmaskinitnext, rnp1->rcu_gp_init_mask);
- onl = !!(rdp->grpmask & rcu_rnp_online_cpus(rnp));
pr_info("%s %d: %c online: %ld(%d) offline: %ld(%d)\n",
- __func__, rdp->cpu, ".o"[onl],
+ __func__, rdp->cpu, ".o"[rcu_rdp_cpu_online(rdp)],
(long)rdp->rcu_onl_gp_seq, rdp->rcu_onl_gp_flags,
(long)rdp->rcu_ofl_gp_seq, rdp->rcu_ofl_gp_flags);
return 1; /* Break things loose after complaining. */
@@ -1738,7 +1752,6 @@ static void rcu_strict_gp_boundary(void *unused)
*/
static noinline_for_stack bool rcu_gp_init(void)
{
- unsigned long firstseq;
unsigned long flags;
unsigned long oldmask;
unsigned long mask;
@@ -1781,22 +1794,17 @@ static noinline_for_stack bool rcu_gp_init(void)
* of RCU's Requirements documentation.
*/
WRITE_ONCE(rcu_state.gp_state, RCU_GP_ONOFF);
+ /* Exclude CPU hotplug operations. */
rcu_for_each_leaf_node(rnp) {
- // Wait for CPU-hotplug operations that might have
- // started before this grace period did.
- smp_mb(); // Pair with barriers used when updating ->ofl_seq to odd values.
- firstseq = READ_ONCE(rnp->ofl_seq);
- if (firstseq & 0x1)
- while (firstseq == READ_ONCE(rnp->ofl_seq))
- schedule_timeout_idle(1); // Can't wake unless RCU is watching.
- smp_mb(); // Pair with barriers used when updating ->ofl_seq to even values.
- raw_spin_lock(&rcu_state.ofl_lock);
- raw_spin_lock_irq_rcu_node(rnp);
+ local_irq_save(flags);
+ arch_spin_lock(&rcu_state.ofl_lock);
+ raw_spin_lock_rcu_node(rnp);
if (rnp->qsmaskinit == rnp->qsmaskinitnext &&
!rnp->wait_blkd_tasks) {
/* Nothing to do on this leaf rcu_node structure. */
- raw_spin_unlock_irq_rcu_node(rnp);
- raw_spin_unlock(&rcu_state.ofl_lock);
+ raw_spin_unlock_rcu_node(rnp);
+ arch_spin_unlock(&rcu_state.ofl_lock);
+ local_irq_restore(flags);
continue;
}
@@ -1831,8 +1839,9 @@ static noinline_for_stack bool rcu_gp_init(void)
rcu_cleanup_dead_rnp(rnp);
}
- raw_spin_unlock_irq_rcu_node(rnp);
- raw_spin_unlock(&rcu_state.ofl_lock);
+ raw_spin_unlock_rcu_node(rnp);
+ arch_spin_unlock(&rcu_state.ofl_lock);
+ local_irq_restore(flags);
}
rcu_gp_slow(gp_preinit_delay); /* Races with CPU hotplug. */
@@ -2849,10 +2858,12 @@ static void rcu_cpu_kthread(unsigned int cpu)
{
unsigned int *statusp = this_cpu_ptr(&rcu_data.rcu_cpu_kthread_status);
char work, *workp = this_cpu_ptr(&rcu_data.rcu_cpu_has_work);
+ unsigned long *j = this_cpu_ptr(&rcu_data.rcuc_activity);
int spincnt;
trace_rcu_utilization(TPS("Start CPU kthread@rcu_run"));
for (spincnt = 0; spincnt < 10; spincnt++) {
+ WRITE_ONCE(*j, jiffies);
local_bh_disable();
*statusp = RCU_KTHREAD_RUNNING;
local_irq_disable();
@@ -2873,6 +2884,7 @@ static void rcu_cpu_kthread(unsigned int cpu)
schedule_timeout_idle(2);
trace_rcu_utilization(TPS("End CPU kthread@rcu_yield"));
*statusp = RCU_KTHREAD_WAITING;
+ WRITE_ONCE(*j, jiffies);
}
static struct smp_hotplug_thread rcu_cpu_thread_spec = {
@@ -2893,7 +2905,7 @@ static int __init rcu_spawn_core_kthreads(void)
for_each_possible_cpu(cpu)
per_cpu(rcu_data.rcu_cpu_has_work, cpu) = 0;
- if (!IS_ENABLED(CONFIG_RCU_BOOST) && use_softirq)
+ if (use_softirq)
return 0;
WARN_ONCE(smpboot_register_percpu_thread(&rcu_cpu_thread_spec),
"%s: Could not start rcuc kthread, OOM is now expected behavior\n", __func__);
@@ -2994,72 +3006,6 @@ static void check_cb_ovld(struct rcu_data *rdp)
raw_spin_unlock_rcu_node(rnp);
}
-/* Helper function for call_rcu() and friends. */
-static void
-__call_rcu(struct rcu_head *head, rcu_callback_t func)
-{
- static atomic_t doublefrees;
- unsigned long flags;
- struct rcu_data *rdp;
- bool was_alldone;
-
- /* Misaligned rcu_head! */
- WARN_ON_ONCE((unsigned long)head & (sizeof(void *) - 1));
-
- if (debug_rcu_head_queue(head)) {
- /*
- * Probable double call_rcu(), so leak the callback.
- * Use rcu:rcu_callback trace event to find the previous
- * time callback was passed to __call_rcu().
- */
- if (atomic_inc_return(&doublefrees) < 4) {
- pr_err("%s(): Double-freed CB %p->%pS()!!! ", __func__, head, head->func);
- mem_dump_obj(head);
- }
- WRITE_ONCE(head->func, rcu_leak_callback);
- return;
- }
- head->func = func;
- head->next = NULL;
- local_irq_save(flags);
- kasan_record_aux_stack_noalloc(head);
- rdp = this_cpu_ptr(&rcu_data);
-
- /* Add the callback to our list. */
- if (unlikely(!rcu_segcblist_is_enabled(&rdp->cblist))) {
- // This can trigger due to call_rcu() from offline CPU:
- WARN_ON_ONCE(rcu_scheduler_active != RCU_SCHEDULER_INACTIVE);
- WARN_ON_ONCE(!rcu_is_watching());
- // Very early boot, before rcu_init(). Initialize if needed
- // and then drop through to queue the callback.
- if (rcu_segcblist_empty(&rdp->cblist))
- rcu_segcblist_init(&rdp->cblist);
- }
-
- check_cb_ovld(rdp);
- if (rcu_nocb_try_bypass(rdp, head, &was_alldone, flags))
- return; // Enqueued onto ->nocb_bypass, so just leave.
- // If no-CBs CPU gets here, rcu_nocb_try_bypass() acquired ->nocb_lock.
- rcu_segcblist_enqueue(&rdp->cblist, head);
- if (__is_kvfree_rcu_offset((unsigned long)func))
- trace_rcu_kvfree_callback(rcu_state.name, head,
- (unsigned long)func,
- rcu_segcblist_n_cbs(&rdp->cblist));
- else
- trace_rcu_callback(rcu_state.name, head,
- rcu_segcblist_n_cbs(&rdp->cblist));
-
- trace_rcu_segcb_stats(&rdp->cblist, TPS("SegCBQueued"));
-
- /* Go handle any RCU core processing required. */
- if (unlikely(rcu_rdp_is_offloaded(rdp))) {
- __call_rcu_nocb_wake(rdp, was_alldone, flags); /* unlocks */
- } else {
- __call_rcu_core(rdp, head, flags);
- local_irq_restore(flags);
- }
-}
-
/**
* call_rcu() - Queue an RCU callback for invocation after a grace period.
* @head: structure to be used for queueing the RCU updates.
@@ -3102,7 +3048,66 @@ __call_rcu(struct rcu_head *head, rcu_callback_t func)
*/
void call_rcu(struct rcu_head *head, rcu_callback_t func)
{
- __call_rcu(head, func);
+ static atomic_t doublefrees;
+ unsigned long flags;
+ struct rcu_data *rdp;
+ bool was_alldone;
+
+ /* Misaligned rcu_head! */
+ WARN_ON_ONCE((unsigned long)head & (sizeof(void *) - 1));
+
+ if (debug_rcu_head_queue(head)) {
+ /*
+ * Probable double call_rcu(), so leak the callback.
+ * Use rcu:rcu_callback trace event to find the previous
+ * time callback was passed to call_rcu().
+ */
+ if (atomic_inc_return(&doublefrees) < 4) {
+ pr_err("%s(): Double-freed CB %p->%pS()!!! ", __func__, head, head->func);
+ mem_dump_obj(head);
+ }
+ WRITE_ONCE(head->func, rcu_leak_callback);
+ return;
+ }
+ head->func = func;
+ head->next = NULL;
+ kasan_record_aux_stack_noalloc(head);
+ local_irq_save(flags);
+ rdp = this_cpu_ptr(&rcu_data);
+
+ /* Add the callback to our list. */
+ if (unlikely(!rcu_segcblist_is_enabled(&rdp->cblist))) {
+ // This can trigger due to call_rcu() from offline CPU:
+ WARN_ON_ONCE(rcu_scheduler_active != RCU_SCHEDULER_INACTIVE);
+ WARN_ON_ONCE(!rcu_is_watching());
+ // Very early boot, before rcu_init(). Initialize if needed
+ // and then drop through to queue the callback.
+ if (rcu_segcblist_empty(&rdp->cblist))
+ rcu_segcblist_init(&rdp->cblist);
+ }
+
+ check_cb_ovld(rdp);
+ if (rcu_nocb_try_bypass(rdp, head, &was_alldone, flags))
+ return; // Enqueued onto ->nocb_bypass, so just leave.
+ // If no-CBs CPU gets here, rcu_nocb_try_bypass() acquired ->nocb_lock.
+ rcu_segcblist_enqueue(&rdp->cblist, head);
+ if (__is_kvfree_rcu_offset((unsigned long)func))
+ trace_rcu_kvfree_callback(rcu_state.name, head,
+ (unsigned long)func,
+ rcu_segcblist_n_cbs(&rdp->cblist));
+ else
+ trace_rcu_callback(rcu_state.name, head,
+ rcu_segcblist_n_cbs(&rdp->cblist));
+
+ trace_rcu_segcb_stats(&rdp->cblist, TPS("SegCBQueued"));
+
+ /* Go handle any RCU core processing required. */
+ if (unlikely(rcu_rdp_is_offloaded(rdp))) {
+ __call_rcu_nocb_wake(rdp, was_alldone, flags); /* unlocks */
+ } else {
+ __call_rcu_core(rdp, head, flags);
+ local_irq_restore(flags);
+ }
}
EXPORT_SYMBOL_GPL(call_rcu);
@@ -3983,13 +3988,16 @@ static void rcu_barrier_callback(struct rcu_head *rhp)
}
/*
- * Called with preemption disabled, and from cross-cpu IRQ context.
+ * If needed, entrain an rcu_barrier() callback on rdp->cblist.
*/
-static void rcu_barrier_func(void *cpu_in)
+static void rcu_barrier_entrain(struct rcu_data *rdp)
{
- uintptr_t cpu = (uintptr_t)cpu_in;
- struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu);
+ unsigned long gseq = READ_ONCE(rcu_state.barrier_sequence);
+ unsigned long lseq = READ_ONCE(rdp->barrier_seq_snap);
+ lockdep_assert_held(&rcu_state.barrier_lock);
+ if (rcu_seq_state(lseq) || !rcu_seq_state(gseq) || rcu_seq_ctr(lseq) != rcu_seq_ctr(gseq))
+ return;
rcu_barrier_trace(TPS("IRQ"), -1, rcu_state.barrier_sequence);
rdp->barrier_head.func = rcu_barrier_callback;
debug_rcu_head_queue(&rdp->barrier_head);
@@ -3999,10 +4007,26 @@ static void rcu_barrier_func(void *cpu_in)
atomic_inc(&rcu_state.barrier_cpu_count);
} else {
debug_rcu_head_unqueue(&rdp->barrier_head);
- rcu_barrier_trace(TPS("IRQNQ"), -1,
- rcu_state.barrier_sequence);
+ rcu_barrier_trace(TPS("IRQNQ"), -1, rcu_state.barrier_sequence);
}
rcu_nocb_unlock(rdp);
+ smp_store_release(&rdp->barrier_seq_snap, gseq);
+}
+
+/*
+ * Called with preemption disabled, and from cross-cpu IRQ context.
+ */
+static void rcu_barrier_handler(void *cpu_in)
+{
+ uintptr_t cpu = (uintptr_t)cpu_in;
+ struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu);
+
+ lockdep_assert_irqs_disabled();
+ WARN_ON_ONCE(cpu != rdp->cpu);
+ WARN_ON_ONCE(cpu != smp_processor_id());
+ raw_spin_lock(&rcu_state.barrier_lock);
+ rcu_barrier_entrain(rdp);
+ raw_spin_unlock(&rcu_state.barrier_lock);
}
/**
@@ -4016,6 +4040,8 @@ static void rcu_barrier_func(void *cpu_in)
void rcu_barrier(void)
{
uintptr_t cpu;
+ unsigned long flags;
+ unsigned long gseq;
struct rcu_data *rdp;
unsigned long s = rcu_seq_snap(&rcu_state.barrier_sequence);
@@ -4026,15 +4052,16 @@ void rcu_barrier(void)
/* Did someone else do our work for us? */
if (rcu_seq_done(&rcu_state.barrier_sequence, s)) {
- rcu_barrier_trace(TPS("EarlyExit"), -1,
- rcu_state.barrier_sequence);
+ rcu_barrier_trace(TPS("EarlyExit"), -1, rcu_state.barrier_sequence);
smp_mb(); /* caller's subsequent code after above check. */
mutex_unlock(&rcu_state.barrier_mutex);
return;
}
/* Mark the start of the barrier operation. */
+ raw_spin_lock_irqsave(&rcu_state.barrier_lock, flags);
rcu_seq_start(&rcu_state.barrier_sequence);
+ gseq = rcu_state.barrier_sequence;
rcu_barrier_trace(TPS("Inc1"), -1, rcu_state.barrier_sequence);
/*
@@ -4046,7 +4073,7 @@ void rcu_barrier(void)
*/
init_completion(&rcu_state.barrier_completion);
atomic_set(&rcu_state.barrier_cpu_count, 2);
- cpus_read_lock();
+ raw_spin_unlock_irqrestore(&rcu_state.barrier_lock, flags);
/*
* Force each CPU with callbacks to register a new callback.
@@ -4055,29 +4082,31 @@ void rcu_barrier(void)
*/
for_each_possible_cpu(cpu) {
rdp = per_cpu_ptr(&rcu_data, cpu);
- if (cpu_is_offline(cpu) &&
- !rcu_rdp_is_offloaded(rdp))
+retry:
+ if (smp_load_acquire(&rdp->barrier_seq_snap) == gseq)
continue;
- if (rcu_segcblist_n_cbs(&rdp->cblist) && cpu_online(cpu)) {
- rcu_barrier_trace(TPS("OnlineQ"), cpu,
- rcu_state.barrier_sequence);
- smp_call_function_single(cpu, rcu_barrier_func, (void *)cpu, 1);
- } else if (rcu_segcblist_n_cbs(&rdp->cblist) &&
- cpu_is_offline(cpu)) {
- rcu_barrier_trace(TPS("OfflineNoCBQ"), cpu,
- rcu_state.barrier_sequence);
- local_irq_disable();
- rcu_barrier_func((void *)cpu);
- local_irq_enable();
- } else if (cpu_is_offline(cpu)) {
- rcu_barrier_trace(TPS("OfflineNoCBNoQ"), cpu,
- rcu_state.barrier_sequence);
- } else {
- rcu_barrier_trace(TPS("OnlineNQ"), cpu,
- rcu_state.barrier_sequence);
+ raw_spin_lock_irqsave(&rcu_state.barrier_lock, flags);
+ if (!rcu_segcblist_n_cbs(&rdp->cblist)) {
+ WRITE_ONCE(rdp->barrier_seq_snap, gseq);
+ raw_spin_unlock_irqrestore(&rcu_state.barrier_lock, flags);
+ rcu_barrier_trace(TPS("NQ"), cpu, rcu_state.barrier_sequence);
+ continue;
}
+ if (!rcu_rdp_cpu_online(rdp)) {
+ rcu_barrier_entrain(rdp);
+ WARN_ON_ONCE(READ_ONCE(rdp->barrier_seq_snap) != gseq);
+ raw_spin_unlock_irqrestore(&rcu_state.barrier_lock, flags);
+ rcu_barrier_trace(TPS("OfflineNoCBQ"), cpu, rcu_state.barrier_sequence);
+ continue;
+ }
+ raw_spin_unlock_irqrestore(&rcu_state.barrier_lock, flags);
+ if (smp_call_function_single(cpu, rcu_barrier_handler, (void *)cpu, 1)) {
+ schedule_timeout_uninterruptible(1);
+ goto retry;
+ }
+ WARN_ON_ONCE(READ_ONCE(rdp->barrier_seq_snap) != gseq);
+ rcu_barrier_trace(TPS("OnlineQ"), cpu, rcu_state.barrier_sequence);
}
- cpus_read_unlock();
/*
* Now that we have an rcu_barrier_callback() callback on each
@@ -4092,6 +4121,12 @@ void rcu_barrier(void)
/* Mark the end of the barrier operation. */
rcu_barrier_trace(TPS("Inc2"), -1, rcu_state.barrier_sequence);
rcu_seq_end(&rcu_state.barrier_sequence);
+ gseq = rcu_state.barrier_sequence;
+ for_each_possible_cpu(cpu) {
+ rdp = per_cpu_ptr(&rcu_data, cpu);
+
+ WRITE_ONCE(rdp->barrier_seq_snap, gseq);
+ }
/* Other rcu_barrier() invocations can now safely proceed. */
mutex_unlock(&rcu_state.barrier_mutex);
@@ -4139,6 +4174,7 @@ rcu_boot_init_percpu_data(int cpu)
INIT_WORK(&rdp->strict_work, strict_work_handler);
WARN_ON_ONCE(rdp->dynticks_nesting != 1);
WARN_ON_ONCE(rcu_dynticks_in_eqs(rcu_dynticks_snap(rdp)));
+ rdp->barrier_seq_snap = rcu_state.barrier_sequence;
rdp->rcu_ofl_gp_seq = rcu_state.gp_seq;
rdp->rcu_ofl_gp_flags = RCU_GP_CLEANED;
rdp->rcu_onl_gp_seq = rcu_state.gp_seq;
@@ -4286,12 +4322,13 @@ void rcu_cpu_starting(unsigned int cpu)
rnp = rdp->mynode;
mask = rdp->grpmask;
- WRITE_ONCE(rnp->ofl_seq, rnp->ofl_seq + 1);
- WARN_ON_ONCE(!(rnp->ofl_seq & 0x1));
+ local_irq_save(flags);
+ arch_spin_lock(&rcu_state.ofl_lock);
rcu_dynticks_eqs_online();
- smp_mb(); // Pair with rcu_gp_cleanup()'s ->ofl_seq barrier().
- raw_spin_lock_irqsave_rcu_node(rnp, flags);
+ raw_spin_lock(&rcu_state.barrier_lock);
+ raw_spin_lock_rcu_node(rnp);
WRITE_ONCE(rnp->qsmaskinitnext, rnp->qsmaskinitnext | mask);
+ raw_spin_unlock(&rcu_state.barrier_lock);
newcpu = !(rnp->expmaskinitnext & mask);
rnp->expmaskinitnext |= mask;
/* Allow lockless access for expedited grace periods. */
@@ -4303,15 +4340,18 @@ void rcu_cpu_starting(unsigned int cpu)
/* An incoming CPU should never be blocking a grace period. */
if (WARN_ON_ONCE(rnp->qsmask & mask)) { /* RCU waiting on incoming CPU? */
+ /* rcu_report_qs_rnp() *really* wants some flags to restore */
+ unsigned long flags2;
+
+ local_irq_save(flags2);
rcu_disable_urgency_upon_qs(rdp);
/* Report QS -after- changing ->qsmaskinitnext! */
- rcu_report_qs_rnp(mask, rnp, rnp->gp_seq, flags);
+ rcu_report_qs_rnp(mask, rnp, rnp->gp_seq, flags2);
} else {
- raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
+ raw_spin_unlock_rcu_node(rnp);
}
- smp_mb(); // Pair with rcu_gp_cleanup()'s ->ofl_seq barrier().
- WRITE_ONCE(rnp->ofl_seq, rnp->ofl_seq + 1);
- WARN_ON_ONCE(rnp->ofl_seq & 0x1);
+ arch_spin_unlock(&rcu_state.ofl_lock);
+ local_irq_restore(flags);
smp_mb(); /* Ensure RCU read-side usage follows above initialization. */
}
@@ -4325,7 +4365,7 @@ void rcu_cpu_starting(unsigned int cpu)
*/
void rcu_report_dead(unsigned int cpu)
{
- unsigned long flags;
+ unsigned long flags, seq_flags;
unsigned long mask;
struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu);
struct rcu_node *rnp = rdp->mynode; /* Outgoing CPU's rdp & rnp. */
@@ -4339,10 +4379,8 @@ void rcu_report_dead(unsigned int cpu)
/* Remove outgoing CPU from mask in the leaf rcu_node structure. */
mask = rdp->grpmask;
- WRITE_ONCE(rnp->ofl_seq, rnp->ofl_seq + 1);
- WARN_ON_ONCE(!(rnp->ofl_seq & 0x1));
- smp_mb(); // Pair with rcu_gp_cleanup()'s ->ofl_seq barrier().
- raw_spin_lock(&rcu_state.ofl_lock);
+ local_irq_save(seq_flags);
+ arch_spin_lock(&rcu_state.ofl_lock);
raw_spin_lock_irqsave_rcu_node(rnp, flags); /* Enforce GP memory-order guarantee. */
rdp->rcu_ofl_gp_seq = READ_ONCE(rcu_state.gp_seq);
rdp->rcu_ofl_gp_flags = READ_ONCE(rcu_state.gp_flags);
@@ -4353,10 +4391,8 @@ void rcu_report_dead(unsigned int cpu)
}
WRITE_ONCE(rnp->qsmaskinitnext, rnp->qsmaskinitnext & ~mask);
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
- raw_spin_unlock(&rcu_state.ofl_lock);
- smp_mb(); // Pair with rcu_gp_cleanup()'s ->ofl_seq barrier().
- WRITE_ONCE(rnp->ofl_seq, rnp->ofl_seq + 1);
- WARN_ON_ONCE(rnp->ofl_seq & 0x1);
+ arch_spin_unlock(&rcu_state.ofl_lock);
+ local_irq_restore(seq_flags);
rdp->cpu_started = false;
}
@@ -4379,7 +4415,9 @@ void rcutree_migrate_callbacks(int cpu)
rcu_segcblist_empty(&rdp->cblist))
return; /* No callbacks to migrate. */
- local_irq_save(flags);
+ raw_spin_lock_irqsave(&rcu_state.barrier_lock, flags);
+ WARN_ON_ONCE(rcu_rdp_cpu_online(rdp));
+ rcu_barrier_entrain(rdp);
my_rdp = this_cpu_ptr(&rcu_data);
my_rnp = my_rdp->mynode;
rcu_nocb_lock(my_rdp); /* irqs already disabled. */
@@ -4389,10 +4427,10 @@ void rcutree_migrate_callbacks(int cpu)
needwake = rcu_advance_cbs(my_rnp, rdp) ||
rcu_advance_cbs(my_rnp, my_rdp);
rcu_segcblist_merge(&my_rdp->cblist, &rdp->cblist);
+ raw_spin_unlock(&rcu_state.barrier_lock); /* irqs remain disabled. */
needwake = needwake || rcu_advance_cbs(my_rnp, my_rdp);
rcu_segcblist_disable(&rdp->cblist);
- WARN_ON_ONCE(rcu_segcblist_empty(&my_rdp->cblist) !=
- !rcu_segcblist_n_cbs(&my_rdp->cblist));
+ WARN_ON_ONCE(rcu_segcblist_empty(&my_rdp->cblist) != !rcu_segcblist_n_cbs(&my_rdp->cblist));
if (rcu_rdp_is_offloaded(my_rdp)) {
raw_spin_unlock_rcu_node(my_rnp); /* irqs remain disabled. */
__call_rcu_nocb_wake(my_rdp, true, flags);
@@ -4439,26 +4477,10 @@ static int rcu_pm_notify(struct notifier_block *self,
static int __init rcu_spawn_gp_kthread(void)
{
unsigned long flags;
- int kthread_prio_in = kthread_prio;
struct rcu_node *rnp;
struct sched_param sp;
struct task_struct *t;
- /* Force priority into range. */
- if (IS_ENABLED(CONFIG_RCU_BOOST) && kthread_prio < 2
- && IS_BUILTIN(CONFIG_RCU_TORTURE_TEST))
- kthread_prio = 2;
- else if (IS_ENABLED(CONFIG_RCU_BOOST) && kthread_prio < 1)
- kthread_prio = 1;
- else if (kthread_prio < 0)
- kthread_prio = 0;
- else if (kthread_prio > 99)
- kthread_prio = 99;
-
- if (kthread_prio != kthread_prio_in)
- pr_alert("rcu_spawn_gp_kthread(): Limited prio to %d from %d\n",
- kthread_prio, kthread_prio_in);
-
rcu_scheduler_fully_active = 1;
t = kthread_create(rcu_gp_kthread, NULL, "%s", rcu_state.name);
if (WARN_ONCE(IS_ERR(t), "%s: Could not start grace-period kthread, OOM is now expected behavior\n", __func__))
@@ -4569,6 +4591,7 @@ static void __init rcu_init_one(void)
init_waitqueue_head(&rnp->exp_wq[2]);
init_waitqueue_head(&rnp->exp_wq[3]);
spin_lock_init(&rnp->exp_lock);
+ mutex_init(&rnp->boost_kthread_mutex);
}
}
@@ -4584,6 +4607,28 @@ static void __init rcu_init_one(void)
}
/*
+ * Force priority from the kernel command-line into range.
+ */
+static void __init sanitize_kthread_prio(void)
+{
+ int kthread_prio_in = kthread_prio;
+
+ if (IS_ENABLED(CONFIG_RCU_BOOST) && kthread_prio < 2
+ && IS_BUILTIN(CONFIG_RCU_TORTURE_TEST))
+ kthread_prio = 2;
+ else if (IS_ENABLED(CONFIG_RCU_BOOST) && kthread_prio < 1)
+ kthread_prio = 1;
+ else if (kthread_prio < 0)
+ kthread_prio = 0;
+ else if (kthread_prio > 99)
+ kthread_prio = 99;
+
+ if (kthread_prio != kthread_prio_in)
+ pr_alert("%s: Limited prio to %d from %d\n",
+ __func__, kthread_prio, kthread_prio_in);
+}
+
+/*
* Compute the rcu_node tree geometry from kernel parameters. This cannot
* replace the definitions in tree.h because those are needed to size
* the ->node array in the rcu_state structure.
@@ -4743,6 +4788,7 @@ void __init rcu_init(void)
kfree_rcu_batch_init();
rcu_bootup_announce();
+ sanitize_kthread_prio();
rcu_init_geometry();
rcu_init_one();
if (dump_tree)
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index 486fc90..926673e 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -56,8 +56,6 @@ struct rcu_node {
/* Initialized from ->qsmaskinitnext at the */
/* beginning of each grace period. */
unsigned long qsmaskinitnext;
- unsigned long ofl_seq; /* CPU-hotplug operation sequence count. */
- /* Online CPUs for next grace period. */
unsigned long expmask; /* CPUs or groups that need to check in */
/* to allow the current expedited GP */
/* to complete. */
@@ -110,6 +108,9 @@ struct rcu_node {
/* side effect, not as a lock. */
unsigned long boost_time;
/* When to start boosting (jiffies). */
+ struct mutex boost_kthread_mutex;
+ /* Exclusion for thread spawning and affinity */
+ /* manipulation. */
struct task_struct *boost_kthread_task;
/* kthread that takes care of priority */
/* boosting for this rcu_node structure. */
@@ -190,6 +191,7 @@ struct rcu_data {
bool rcu_forced_tick_exp; /* ... provide QS to expedited GP. */
/* 4) rcu_barrier(), OOM callbacks, and expediting. */
+ unsigned long barrier_seq_snap; /* Snap of rcu_state.barrier_sequence. */
struct rcu_head barrier_head;
int exp_dynticks_snap; /* Double-check need for IPI. */
@@ -203,6 +205,8 @@ struct rcu_data {
int nocb_defer_wakeup; /* Defer wakeup of nocb_kthread. */
struct timer_list nocb_timer; /* Enforce finite deferral. */
unsigned long nocb_gp_adv_time; /* Last call_rcu() CB adv (jiffies). */
+ struct mutex nocb_gp_kthread_mutex; /* Exclusion for nocb gp kthread */
+ /* spawning */
/* The following fields are used by call_rcu, hence own cacheline. */
raw_spinlock_t nocb_bypass_lock ____cacheline_internodealigned_in_smp;
@@ -237,6 +241,7 @@ struct rcu_data {
/* rcuc per-CPU kthread or NULL. */
unsigned int rcu_cpu_kthread_status;
char rcu_cpu_has_work;
+ unsigned long rcuc_activity;
/* 7) Diagnostic data, including RCU CPU stall warnings. */
unsigned int softirq_snap; /* Snapshot of softirq activity. */
@@ -302,9 +307,8 @@ struct rcu_state {
/* The following fields are guarded by the root rcu_node's lock. */
- u8 boost ____cacheline_internodealigned_in_smp;
- /* Subject to priority boost. */
- unsigned long gp_seq; /* Grace-period sequence #. */
+ unsigned long gp_seq ____cacheline_internodealigned_in_smp;
+ /* Grace-period sequence #. */
unsigned long gp_max; /* Maximum GP duration in */
/* jiffies. */
struct task_struct *gp_kthread; /* Task for grace periods. */
@@ -323,6 +327,8 @@ struct rcu_state {
/* rcu_barrier(). */
/* End of fields guarded by barrier_mutex. */
+ raw_spinlock_t barrier_lock; /* Protects ->barrier_seq_snap. */
+
struct mutex exp_mutex; /* Serialize expedited GP. */
struct mutex exp_wake_mutex; /* Serialize wakeup. */
unsigned long expedited_sequence; /* Take a ticket. */
@@ -355,7 +361,7 @@ struct rcu_state {
const char *name; /* Name of structure. */
char abbr; /* Abbreviated name. */
- raw_spinlock_t ofl_lock ____cacheline_internodealigned_in_smp;
+ arch_spinlock_t ofl_lock ____cacheline_internodealigned_in_smp;
/* Synchronize offline with */
/* GP pre-initialization. */
};
diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h
index 237a799..60197ea 100644
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@ -502,7 +502,8 @@ static void synchronize_rcu_expedited_wait(void)
if (synchronize_rcu_expedited_wait_once(1))
return;
rcu_for_each_leaf_node(rnp) {
- for_each_leaf_node_cpu_mask(rnp, cpu, rnp->expmask) {
+ mask = READ_ONCE(rnp->expmask);
+ for_each_leaf_node_cpu_mask(rnp, cpu, mask) {
rdp = per_cpu_ptr(&rcu_data, cpu);
if (rdp->rcu_forced_tick_exp)
continue;
@@ -656,7 +657,7 @@ static void rcu_exp_handler(void *unused)
*/
if (!depth) {
if (!(preempt_count() & (PREEMPT_MASK | SOFTIRQ_MASK)) ||
- rcu_dynticks_curr_cpu_in_eqs()) {
+ rcu_is_cpu_rrupt_from_idle()) {
rcu_report_exp_rdp(rdp);
} else {
WRITE_ONCE(rdp->cpu_no_qs.b.exp, true);
diff --git a/kernel/rcu/tree_nocb.h b/kernel/rcu/tree_nocb.h
index eeafb54..636d054 100644
--- a/kernel/rcu/tree_nocb.h
+++ b/kernel/rcu/tree_nocb.h
@@ -1169,7 +1169,7 @@ void __init rcu_init_nohz(void)
struct rcu_data *rdp;
#if defined(CONFIG_NO_HZ_FULL)
- if (tick_nohz_full_running && cpumask_weight(tick_nohz_full_mask))
+ if (tick_nohz_full_running && !cpumask_empty(tick_nohz_full_mask))
need_rcu_nocb_mask = true;
#endif /* #if defined(CONFIG_NO_HZ_FULL) */
@@ -1226,6 +1226,7 @@ static void __init rcu_boot_init_nocb_percpu_data(struct rcu_data *rdp)
raw_spin_lock_init(&rdp->nocb_gp_lock);
timer_setup(&rdp->nocb_timer, do_nocb_deferred_wakeup_timer, 0);
rcu_cblist_init(&rdp->nocb_bypass);
+ mutex_init(&rdp->nocb_gp_kthread_mutex);
}
/*
@@ -1238,6 +1239,7 @@ static void rcu_spawn_cpu_nocb_kthread(int cpu)
struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu);
struct rcu_data *rdp_gp;
struct task_struct *t;
+ struct sched_param sp;
if (!rcu_scheduler_fully_active || !rcu_nocb_is_setup)
return;
@@ -1247,20 +1249,30 @@ static void rcu_spawn_cpu_nocb_kthread(int cpu)
return;
/* If we didn't spawn the GP kthread first, reorganize! */
+ sp.sched_priority = kthread_prio;
rdp_gp = rdp->nocb_gp_rdp;
+ mutex_lock(&rdp_gp->nocb_gp_kthread_mutex);
if (!rdp_gp->nocb_gp_kthread) {
t = kthread_run(rcu_nocb_gp_kthread, rdp_gp,
"rcuog/%d", rdp_gp->cpu);
- if (WARN_ONCE(IS_ERR(t), "%s: Could not start rcuo GP kthread, OOM is now expected behavior\n", __func__))
+ if (WARN_ONCE(IS_ERR(t), "%s: Could not start rcuo GP kthread, OOM is now expected behavior\n", __func__)) {
+ mutex_unlock(&rdp_gp->nocb_gp_kthread_mutex);
return;
+ }
WRITE_ONCE(rdp_gp->nocb_gp_kthread, t);
+ if (kthread_prio)
+ sched_setscheduler_nocheck(t, SCHED_FIFO, &sp);
}
+ mutex_unlock(&rdp_gp->nocb_gp_kthread_mutex);
/* Spawn the kthread for this CPU. */
t = kthread_run(rcu_nocb_cb_kthread, rdp,
"rcuo%c/%d", rcu_state.abbr, cpu);
if (WARN_ONCE(IS_ERR(t), "%s: Could not start rcuo CB kthread, OOM is now expected behavior\n", __func__))
return;
+
+ if (kthread_prio)
+ sched_setscheduler_nocheck(t, SCHED_FIFO, &sp);
WRITE_ONCE(rdp->nocb_cb_kthread, t);
WRITE_ONCE(rdp->nocb_gp_kthread, rdp_gp->nocb_gp_kthread);
}
@@ -1348,7 +1360,7 @@ static void __init rcu_organize_nocb_kthreads(void)
*/
void rcu_bind_current_to_nocb(void)
{
- if (cpumask_available(rcu_nocb_mask) && cpumask_weight(rcu_nocb_mask))
+ if (cpumask_available(rcu_nocb_mask) && !cpumask_empty(rcu_nocb_mask))
WARN_ON(sched_setaffinity(current->pid, rcu_nocb_mask));
}
EXPORT_SYMBOL_GPL(rcu_bind_current_to_nocb);
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index c5b45c2..6082dd2 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -330,7 +330,7 @@ void rcu_note_context_switch(bool preempt)
* then queue the task as required based on the states
* of any ongoing and expedited grace periods.
*/
- WARN_ON_ONCE((rdp->grpmask & rcu_rnp_online_cpus(rnp)) == 0);
+ WARN_ON_ONCE(!rcu_rdp_cpu_online(rdp));
WARN_ON_ONCE(!list_empty(&t->rcu_node_entry));
trace_rcu_preempt_task(rcu_state.name,
t->pid,
@@ -556,16 +556,16 @@ rcu_preempt_deferred_qs_irqrestore(struct task_struct *t, unsigned long flags)
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
}
- /* Unboost if we were boosted. */
- if (IS_ENABLED(CONFIG_RCU_BOOST) && drop_boost_mutex)
- rt_mutex_futex_unlock(&rnp->boost_mtx.rtmutex);
-
/*
* If this was the last task on the expedited lists,
* then we need to report up the rcu_node hierarchy.
*/
if (!empty_exp && empty_exp_now)
rcu_report_exp_rnp(rnp, true);
+
+ /* Unboost if we were boosted. */
+ if (IS_ENABLED(CONFIG_RCU_BOOST) && drop_boost_mutex)
+ rt_mutex_futex_unlock(&rnp->boost_mtx.rtmutex);
} else {
local_irq_restore(flags);
}
@@ -773,7 +773,6 @@ dump_blkd_tasks(struct rcu_node *rnp, int ncheck)
int cpu;
int i;
struct list_head *lhp;
- bool onl;
struct rcu_data *rdp;
struct rcu_node *rnp1;
@@ -797,9 +796,8 @@ dump_blkd_tasks(struct rcu_node *rnp, int ncheck)
pr_cont("\n");
for (cpu = rnp->grplo; cpu <= rnp->grphi; cpu++) {
rdp = per_cpu_ptr(&rcu_data, cpu);
- onl = !!(rdp->grpmask & rcu_rnp_online_cpus(rnp));
pr_info("\t%d: %c online: %ld(%d) offline: %ld(%d)\n",
- cpu, ".o"[onl],
+ cpu, ".o"[rcu_rdp_cpu_online(rdp)],
(long)rdp->rcu_onl_gp_seq, rdp->rcu_onl_gp_flags,
(long)rdp->rcu_ofl_gp_seq, rdp->rcu_ofl_gp_flags);
}
@@ -996,12 +994,15 @@ dump_blkd_tasks(struct rcu_node *rnp, int ncheck)
*/
static void rcu_cpu_kthread_setup(unsigned int cpu)
{
+ struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu);
#ifdef CONFIG_RCU_BOOST
struct sched_param sp;
sp.sched_priority = kthread_prio;
sched_setscheduler_nocheck(current, SCHED_FIFO, &sp);
#endif /* #ifdef CONFIG_RCU_BOOST */
+
+ WRITE_ONCE(rdp->rcuc_activity, jiffies);
}
#ifdef CONFIG_RCU_BOOST
@@ -1172,15 +1173,14 @@ static void rcu_spawn_one_boost_kthread(struct rcu_node *rnp)
struct sched_param sp;
struct task_struct *t;
+ mutex_lock(&rnp->boost_kthread_mutex);
if (rnp->boost_kthread_task || !rcu_scheduler_fully_active)
- return;
-
- rcu_state.boost = 1;
+ goto out;
t = kthread_create(rcu_boost_kthread, (void *)rnp,
"rcub/%d", rnp_index);
if (WARN_ON_ONCE(IS_ERR(t)))
- return;
+ goto out;
raw_spin_lock_irqsave_rcu_node(rnp, flags);
rnp->boost_kthread_task = t;
@@ -1188,6 +1188,9 @@ static void rcu_spawn_one_boost_kthread(struct rcu_node *rnp)
sp.sched_priority = kthread_prio;
sched_setscheduler_nocheck(t, SCHED_FIFO, &sp);
wake_up_process(t); /* get to TASK_INTERRUPTIBLE quickly. */
+
+ out:
+ mutex_unlock(&rnp->boost_kthread_mutex);
}
/*
@@ -1210,14 +1213,16 @@ static void rcu_boost_kthread_setaffinity(struct rcu_node *rnp, int outgoingcpu)
return;
if (!zalloc_cpumask_var(&cm, GFP_KERNEL))
return;
+ mutex_lock(&rnp->boost_kthread_mutex);
for_each_leaf_node_possible_cpu(rnp, cpu)
if ((mask & leaf_node_cpu_bit(rnp, cpu)) &&
cpu != outgoingcpu)
cpumask_set_cpu(cpu, cm);
cpumask_and(cm, cm, housekeeping_cpumask(HK_FLAG_RCU));
- if (cpumask_weight(cm) == 0)
+ if (cpumask_empty(cm))
cpumask_copy(cm, housekeeping_cpumask(HK_FLAG_RCU));
set_cpus_allowed_ptr(t, cm);
+ mutex_unlock(&rnp->boost_kthread_mutex);
free_cpumask_var(cm);
}
diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h
index 21bebf7..0c5d851 100644
--- a/kernel/rcu/tree_stall.h
+++ b/kernel/rcu/tree_stall.h
@@ -379,6 +379,15 @@ static bool rcu_is_gp_kthread_starving(unsigned long *jp)
return j > 2 * HZ;
}
+static bool rcu_is_rcuc_kthread_starving(struct rcu_data *rdp, unsigned long *jp)
+{
+ unsigned long j = jiffies - READ_ONCE(rdp->rcuc_activity);
+
+ if (jp)
+ *jp = j;
+ return j > 2 * HZ;
+}
+
/*
* Print out diagnostic information for the specified stalled CPU.
*
@@ -430,6 +439,29 @@ static void print_cpu_stall_info(int cpu)
falsepositive ? " (false positive?)" : "");
}
+static void rcuc_kthread_dump(struct rcu_data *rdp)
+{
+ int cpu;
+ unsigned long j;
+ struct task_struct *rcuc;
+
+ rcuc = rdp->rcu_cpu_kthread_task;
+ if (!rcuc)
+ return;
+
+ cpu = task_cpu(rcuc);
+ if (cpu_is_offline(cpu) || idle_cpu(cpu))
+ return;
+
+ if (!rcu_is_rcuc_kthread_starving(rdp, &j))
+ return;
+
+ pr_err("%s kthread starved for %ld jiffies\n", rcuc->comm, j);
+ sched_show_task(rcuc);
+ if (!trigger_single_cpu_backtrace(cpu))
+ dump_cpu_task(cpu);
+}
+
/* Complain about starvation of grace-period kthread. */
static void rcu_check_gp_kthread_starvation(void)
{
@@ -601,6 +633,9 @@ static void print_cpu_stall(unsigned long gps)
rcu_check_gp_kthread_expired_fqs_timer();
rcu_check_gp_kthread_starvation();
+ if (!use_softirq)
+ rcuc_kthread_dump(rdp);
+
rcu_dump_cpu_stacks();
raw_spin_lock_irqsave_rcu_node(rnp, flags);
diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
index 156892c..180ff9c 100644
--- a/kernel/rcu/update.c
+++ b/kernel/rcu/update.c
@@ -407,6 +407,13 @@ void __wait_rcu_gp(bool checktiny, int n, call_rcu_func_t *crcu_array,
}
EXPORT_SYMBOL_GPL(__wait_rcu_gp);
+void finish_rcuwait(struct rcuwait *w)
+{
+ rcu_assign_pointer(w->task, NULL);
+ __set_current_state(TASK_RUNNING);
+}
+EXPORT_SYMBOL_GPL(finish_rcuwait);
+
#ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
void init_rcu_head(struct rcu_head *head)
{
diff --git a/kernel/torture.c b/kernel/torture.c
index ef27a6c..789aeb0 100644
--- a/kernel/torture.c
+++ b/kernel/torture.c
@@ -911,7 +911,7 @@ void torture_kthread_stopping(char *title)
{
char buf[128];
- snprintf(buf, sizeof(buf), "Stopping %s", title);
+ snprintf(buf, sizeof(buf), "%s is stopping", title);
VERBOSE_TOROUT_STRING(buf);
while (!kthread_should_stop()) {
torture_shutdown_absorb(title);
@@ -931,12 +931,14 @@ int _torture_create_kthread(int (*fn)(void *arg), void *arg, char *s, char *m,
int ret = 0;
VERBOSE_TOROUT_STRING(m);
- *tp = kthread_run(fn, arg, "%s", s);
+ *tp = kthread_create(fn, arg, "%s", s);
if (IS_ERR(*tp)) {
ret = PTR_ERR(*tp);
TOROUT_ERRSTRING(f);
*tp = NULL;
+ return ret;
}
+ wake_up_process(*tp); // Process is sleeping, so ordering provided.
torture_shuffle_task_register(*tp);
return ret;
}
diff --git a/tools/testing/selftests/rcutorture/bin/console-badness.sh b/tools/testing/selftests/rcutorture/bin/console-badness.sh
index e6a132d..69f8a59 100755
--- a/tools/testing/selftests/rcutorture/bin/console-badness.sh
+++ b/tools/testing/selftests/rcutorture/bin/console-badness.sh
@@ -10,7 +10,7 @@
#
# Authors: Paul E. McKenney <paulmck@kernel.org>
-egrep 'Badness|WARNING:|Warn|BUG|===========|Call Trace:|Oops:|detected stalls on CPUs/tasks:|self-detected stall on CPU|Stall ended before state dump start|\?\?\? Writer stall state|rcu_.*kthread starved for|!!!' |
+egrep 'Badness|WARNING:|Warn|BUG|===========|BUG: KCSAN:|Call Trace:|Oops:|detected stalls on CPUs/tasks:|self-detected stall on CPU|Stall ended before state dump start|\?\?\? Writer stall state|rcu_.*kthread starved for|!!!' |
grep -v 'ODEBUG: ' |
grep -v 'This means that this is a DEBUG kernel and it is' |
grep -v 'Warning: unable to open an initial console' |
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-again.sh b/tools/testing/selftests/rcutorture/bin/kvm-again.sh
index 5a0023d..0941f1d 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-again.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-again.sh
@@ -47,8 +47,8 @@
exit 1
fi
-KVM="`pwd`/tools/testing/selftests/rcutorture"; export KVM
-PATH=${KVM}/bin:$PATH; export PATH
+RCUTORTURE="`pwd`/tools/testing/selftests/rcutorture"; export RCUTORTURE
+PATH=${RCUTORTURE}/bin:$PATH; export PATH
. functions.sh
dryrun=
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-check-branches.sh b/tools/testing/selftests/rcutorture/bin/kvm-check-branches.sh
index 370406bb..f17000a2 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-check-branches.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-check-branches.sh
@@ -49,8 +49,8 @@
mkdir $resdir/$ds
echo Results directory: $resdir/$ds
-KVM="`pwd`/tools/testing/selftests/rcutorture"; export KVM
-PATH=${KVM}/bin:$PATH; export PATH
+RCUTORTURE="`pwd`/tools/testing/selftests/rcutorture"; export RCUTORTURE
+PATH=${RCUTORTURE}/bin:$PATH; export PATH
. functions.sh
echo Using all `identify_qemu_vcpus` CPUs.
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-end-run-stats.sh b/tools/testing/selftests/rcutorture/bin/kvm-end-run-stats.sh
index e4a0077..ee886b4 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-end-run-stats.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-end-run-stats.sh
@@ -22,8 +22,8 @@
trap 'rm -rf $T' 0
mkdir $T
-KVM="`pwd`/tools/testing/selftests/rcutorture"; export KVM
-PATH=${KVM}/bin:$PATH; export PATH
+RCUTORTURE="`pwd`/tools/testing/selftests/rcutorture"; export RCUTORTURE
+PATH=${RCUTORTURE}/bin:$PATH; export PATH
. functions.sh
default_starttime="`get_starttime`"
starttime="${2-default_starttime}"
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-find-errors.sh b/tools/testing/selftests/rcutorture/bin/kvm-find-errors.sh
index 2e9e9e2..5f682fc 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-find-errors.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-find-errors.sh
@@ -30,10 +30,16 @@
files=
for i in ${rundir}/*/Make.out
do
+ scenariodir="`dirname $i`"
+ scenariobasedir="`echo ${scenariodir} | sed -e 's/\.[0-9]*$//'`"
if egrep -q "error:|warning:|^ld: .*undefined reference to" < $i
then
egrep "error:|warning:|^ld: .*undefined reference to" < $i > $i.diags
files="$files $i.diags $i"
+ elif ! test -f ${scenariobasedir}/vmlinux
+ then
+ echo No ${scenariobasedir}/vmlinux file > $i.diags
+ files="$files $i.diags $i"
fi
done
if test -n "$files"
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-recheck-rcu.sh b/tools/testing/selftests/rcutorture/bin/kvm-recheck-rcu.sh
index 1c4c2c7..43e1387 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-recheck-rcu.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-recheck-rcu.sh
@@ -25,7 +25,7 @@
tail -1 | sed -e 's/^\[[ 0-9.]*] //' |
awk '{ print \"[\" $1 \" \" $5 \" \" $6 \" \" $7 \"]\"; }' |
tr -d '\012\015'`"
-fwdprog="`grep 'rcu_torture_fwd_prog n_max_cbs: ' $i/console.log 2> /dev/null | sed -e 's/^\[[^]]*] //' | sort -k3nr | head -1 | awk '{ print $2 " " $3 }'`"
+fwdprog="`grep 'rcu_torture_fwd_prog n_max_cbs: ' $i/console.log 2> /dev/null | sed -e 's/^\[[^]]*] //' | sort -k3nr | head -1 | awk '{ print $2 " " $3 }' | tr -d '\015'`"
if test -z "$ngps"
then
echo "$configfile ------- " $stopstate
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-remote.sh b/tools/testing/selftests/rcutorture/bin/kvm-remote.sh
index e09b1bc7..8c4c1e4 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-remote.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-remote.sh
@@ -19,8 +19,8 @@
exit 1
fi
-KVM="`pwd`/tools/testing/selftests/rcutorture"; export KVM
-PATH=${KVM}/bin:$PATH; export PATH
+RCUTORTURE="`pwd`/tools/testing/selftests/rcutorture"; export RCUTORTURE
+PATH=${RCUTORTURE}/bin:$PATH; export PATH
. functions.sh
starttime="`get_starttime`"
@@ -108,8 +108,8 @@
cat $T/kvm-again.sh.out | tee -a "$oldrun/remote-log"
exit 2
fi
- cp -a "$rundir" "$KVM/res/"
- oldrun="$KVM/res/$ds"
+ cp -a "$rundir" "$RCUTORTURE/res/"
+ oldrun="$RCUTORTURE/res/$ds"
fi
echo | tee -a "$oldrun/remote-log"
echo " ----" kvm-again.sh output: "(`date`)" | tee -a "$oldrun/remote-log"
@@ -155,18 +155,23 @@
echo Downloading tarball to $i `date` | tee -a "$oldrun/remote-log"
cat $T/binres.tgz | ssh $i "cd /tmp; tar -xzf -"
ret=$?
- if test "$ret" -ne 0
- then
- echo Unable to download $T/binres.tgz to system $i, waiting and then retrying. | tee -a "$oldrun/remote-log"
+ tries=0
+ while test "$ret" -ne 0
+ do
+ echo Unable to download $T/binres.tgz to system $i, waiting and then retrying. $tries prior retries. | tee -a "$oldrun/remote-log"
sleep 60
cat $T/binres.tgz | ssh $i "cd /tmp; tar -xzf -"
ret=$?
if test "$ret" -ne 0
then
- echo Unable to download $T/binres.tgz to system $i, giving up. | tee -a "$oldrun/remote-log"
- exit 10
+ if test "$tries" > 5
+ then
+ echo Unable to download $T/binres.tgz to system $i, giving up. | tee -a "$oldrun/remote-log"
+ exit 10
+ fi
fi
- fi
+ tries=$((tries+1))
+ done
done
# Function to check for presence of a file on the specified system.
diff --git a/tools/testing/selftests/rcutorture/bin/kvm.sh b/tools/testing/selftests/rcutorture/bin/kvm.sh
index 6de0c18..55b2c15 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm.sh
@@ -25,15 +25,15 @@
dur=$((30*60))
dryrun=""
-KVM="`pwd`/tools/testing/selftests/rcutorture"; export KVM
-PATH=${KVM}/bin:$PATH; export PATH
+RCUTORTURE="`pwd`/tools/testing/selftests/rcutorture"; export RCUTORTURE
+PATH=${RCUTORTURE}/bin:$PATH; export PATH
. functions.sh
TORTURE_ALLOTED_CPUS="`identify_qemu_vcpus`"
TORTURE_DEFCONFIG=defconfig
TORTURE_BOOT_IMAGE=""
TORTURE_BUILDONLY=
-TORTURE_INITRD="$KVM/initrd"; export TORTURE_INITRD
+TORTURE_INITRD="$RCUTORTURE/initrd"; export TORTURE_INITRD
TORTURE_KCONFIG_ARG=""
TORTURE_KCONFIG_GDB_ARG=""
TORTURE_BOOT_GDB_ARG=""
@@ -262,7 +262,7 @@
exit 1
fi
-CONFIGFRAG=${KVM}/configs/${TORTURE_SUITE}; export CONFIGFRAG
+CONFIGFRAG=${RCUTORTURE}/configs/${TORTURE_SUITE}; export CONFIGFRAG
defaultconfigs="`tr '\012' ' ' < $CONFIGFRAG/CFLIST`"
if test -z "$configs"
@@ -272,7 +272,7 @@
if test -z "$resdir"
then
- resdir=$KVM/res
+ resdir=$RCUTORTURE/res
fi
# Create a file of test-name/#cpus pairs, sorted by decreasing #cpus.
@@ -280,7 +280,7 @@
for CF in $configs
do
case $CF in
- [0-9]\**|[0-9][0-9]\**|[0-9][0-9][0-9]\**)
+ [0-9]\**|[0-9][0-9]\**|[0-9][0-9][0-9]\**|[0-9][0-9][0-9][0-9]\**)
config_reps=`echo $CF | sed -e 's/\*.*$//'`
CF1=`echo $CF | sed -e 's/^[^*]*\*//'`
;;
@@ -386,7 +386,7 @@
# Generate a script to execute the tests in appropriate batches.
cat << ___EOF___ > $T/script
CONFIGFRAG="$CONFIGFRAG"; export CONFIGFRAG
-KVM="$KVM"; export KVM
+RCUTORTURE="$RCUTORTURE"; export RCUTORTURE
PATH="$PATH"; export PATH
TORTURE_ALLOTED_CPUS="$TORTURE_ALLOTED_CPUS"; export TORTURE_ALLOTED_CPUS
TORTURE_BOOT_IMAGE="$TORTURE_BOOT_IMAGE"; export TORTURE_BOOT_IMAGE
@@ -569,7 +569,7 @@
awk < $T/cfgcpu.pack \
-v TORTURE_BUILDONLY="$TORTURE_BUILDONLY" \
-v CONFIGDIR="$CONFIGFRAG/" \
- -v KVM="$KVM" \
+ -v RCUTORTURE="$RCUTORTURE" \
-v ncpus=$cpus \
-v jitter="$jitter" \
-v rd=$resdir/$ds/ \
diff --git a/tools/testing/selftests/rcutorture/bin/parse-console.sh b/tools/testing/selftests/rcutorture/bin/parse-console.sh
index 9f624bd..822eb03 100755
--- a/tools/testing/selftests/rcutorture/bin/parse-console.sh
+++ b/tools/testing/selftests/rcutorture/bin/parse-console.sh
@@ -138,6 +138,16 @@
then
summary="$summary Bugs: $n_bugs"
fi
+ n_kcsan=`egrep -c 'BUG: KCSAN: ' $file`
+ if test "$n_kcsan" -ne 0
+ then
+ if test "$n_bugs" = "$n_kcsan"
+ then
+ summary="$summary (all bugs kcsan)"
+ else
+ summary="$summary KCSAN: $n_kcsan"
+ fi
+ fi
n_calltrace=`grep -c 'Call Trace:' $file`
if test "$n_calltrace" -ne 0
then
diff --git a/tools/testing/selftests/rcutorture/bin/torture.sh b/tools/testing/selftests/rcutorture/bin/torture.sh
index eae88aa..bfe09e2 100755
--- a/tools/testing/selftests/rcutorture/bin/torture.sh
+++ b/tools/testing/selftests/rcutorture/bin/torture.sh
@@ -13,8 +13,8 @@
scriptname=$0
args="$*"
-KVM="`pwd`/tools/testing/selftests/rcutorture"; export KVM
-PATH=${KVM}/bin:$PATH; export PATH
+RCUTORTURE="`pwd`/tools/testing/selftests/rcutorture"; export RCUTORTURE
+PATH=${RCUTORTURE}/bin:$PATH; export PATH
. functions.sh
TORTURE_ALLOTED_CPUS="`identify_qemu_vcpus`"
@@ -37,7 +37,7 @@
kcsan_kmake_args=
# Default compression, duration, and apportionment.
-compress_kasan_vmlinux="`identify_qemu_vcpus`"
+compress_concurrency="`identify_qemu_vcpus`"
duration_base=10
duration_rcutorture_frac=7
duration_locktorture_frac=1
@@ -67,12 +67,12 @@
usage () {
echo "Usage: $scriptname optional arguments:"
- echo " --compress-kasan-vmlinux concurrency"
+ echo " --compress-concurrency concurrency"
echo " --configs-rcutorture \"config-file list w/ repeat factor (3*TINY01)\""
echo " --configs-locktorture \"config-file list w/ repeat factor (10*LOCK01)\""
echo " --configs-scftorture \"config-file list w/ repeat factor (2*CFLIST)\""
- echo " --doall"
- echo " --doallmodconfig / --do-no-allmodconfig"
+ echo " --do-all"
+ echo " --do-allmodconfig / --do-no-allmodconfig"
echo " --do-clocksourcewd / --do-no-clocksourcewd"
echo " --do-kasan / --do-no-kasan"
echo " --do-kcsan / --do-no-kcsan"
@@ -91,9 +91,9 @@
while test $# -gt 0
do
case "$1" in
- --compress-kasan-vmlinux)
- checkarg --compress-kasan-vmlinux "(concurrency level)" $# "$2" '^[0-9][0-9]*$' '^error'
- compress_kasan_vmlinux=$2
+ --compress-concurrency)
+ checkarg --compress-concurrency "(concurrency level)" $# "$2" '^[0-9][0-9]*$' '^error'
+ compress_concurrency=$2
shift
;;
--config-rcutorture|--configs-rcutorture)
@@ -414,8 +414,14 @@
echo FAILURES: | tee -a $T/log
if test -s "$T/failures"
then
- cat "$T/failures" | tee -a $T/log
+ awk < "$T/failures" -v sq="'" '{ print "echo " sq $0 sq; print "sed -e " sq "1,/^ --- .* Test summary:$/d" sq " " $2 "/log | grep Summary: | sed -e " sq "s/^[^S]*/ /" sq; }' | sh | tee -a $T/log | tee "$T/failuresum"
nfailures="`wc -l "$T/failures" | awk '{ print $1 }'`"
+ grep "^ Summary: " "$T/failuresum" |
+ grep -v '^ Summary: Bugs: [0-9]* (all bugs kcsan)$' > "$T/nonkcsan"
+ if test -s "$T/nonkcsan"
+ then
+ nonkcsanbug="yes"
+ fi
ret=2
fi
if test "$do_kcsan" = "yes"
@@ -424,12 +430,16 @@
fi
echo Started at $startdate, ended at `date`, duration `get_starttime_duration $starttime`. | tee -a $T/log
echo Summary: Successes: $nsuccesses Failures: $nfailures. | tee -a $T/log
+if test -z "$nonkcsanbug" && test -s "$T/failuresum"
+then
+ echo " All bugs were KCSAN failures."
+fi
tdir="`cat $T/successes $T/failures | head -1 | awk '{ print $NF }' | sed -e 's,/[^/]\+/*$,,'`"
-if test -n "$tdir" && test $compress_kasan_vmlinux -gt 0
+if test -n "$tdir" && test $compress_concurrency -gt 0
then
# KASAN vmlinux files can approach 1GB in size, so compress them.
- echo Looking for KASAN files to compress: `date` > "$tdir/log-xz" 2>&1
- find "$tdir" -type d -name '*-kasan' -print > $T/xz-todo
+ echo Looking for K[AC]SAN files to compress: `date` > "$tdir/log-xz" 2>&1
+ find "$tdir" -type d -name '*-k[ac]san' -print > $T/xz-todo
ncompresses=0
batchno=1
if test -s $T/xz-todo
@@ -447,7 +457,7 @@
do
xz "$j" >> "$tdir/log-xz" 2>&1 &
ncompresses=$((ncompresses+1))
- if test $ncompresses -ge $compress_kasan_vmlinux
+ if test $ncompresses -ge $compress_concurrency
then
echo Waiting for batch $batchno of $ncompresses compressions `date` | tee -a "$tdir/log-xz" | tee -a $T/log
wait
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/RUDE01 b/tools/testing/selftests/rcutorture/configs/rcu/RUDE01
index 3ca1124..7093422 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/RUDE01
+++ b/tools/testing/selftests/rcutorture/configs/rcu/RUDE01
@@ -1,5 +1,5 @@
CONFIG_SMP=y
-CONFIG_NR_CPUS=4
+CONFIG_NR_CPUS=3
CONFIG_HOTPLUG_CPU=y
CONFIG_PREEMPT_NONE=n
CONFIG_PREEMPT_VOLUNTARY=n
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/SRCU-N.boot b/tools/testing/selftests/rcutorture/configs/rcu/SRCU-N.boot
index 238bfe3..ce0694f 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/SRCU-N.boot
+++ b/tools/testing/selftests/rcutorture/configs/rcu/SRCU-N.boot
@@ -1 +1,2 @@
rcutorture.torture_type=srcu
+rcutorture.fwd_progress=3
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/SRCU-P.boot b/tools/testing/selftests/rcutorture/configs/rcu/SRCU-P.boot
index ce48c7b..2db39f2 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/SRCU-P.boot
+++ b/tools/testing/selftests/rcutorture/configs/rcu/SRCU-P.boot
@@ -1,2 +1,4 @@
rcutorture.torture_type=srcud
rcupdate.rcu_self_test=1
+rcutorture.fwd_progress=3
+srcutree.big_cpu_lim=5
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TRACE01 b/tools/testing/selftests/rcutorture/configs/rcu/TRACE01
index 34c8ff5a..e4d74e5 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/TRACE01
+++ b/tools/testing/selftests/rcutorture/configs/rcu/TRACE01
@@ -1,5 +1,5 @@
CONFIG_SMP=y
-CONFIG_NR_CPUS=4
+CONFIG_NR_CPUS=5
CONFIG_HOTPLUG_CPU=y
CONFIG_PREEMPT_NONE=y
CONFIG_PREEMPT_VOLUNTARY=n
