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authorPaul E. McKenney <paulmck@kernel.org>2019-07-28 12:00:48 -0700
committerPaul E. McKenney <paulmck@kernel.org>2019-10-05 10:46:04 -0700
commitd38e6dc6ed0dfef8d323354031a1ee1a7cfdedc1 (patch)
treebccce24309a5ef53479699a55b14ccb31cc98a36 /kernel/rcu
parent6a949b7af82db7eb1e52caaed122eab1cf63acee (diff)
rcutorture: Force on tick for readers and callback flooders
Readers and callback flooders in the rcutorture stress-test suite run for extended time periods by design. They do take pains to relinquish the CPU from time to time, but in some cases this relies on the scheduler being active, which in turn relies on the scheduler-clock interrupt firing from time to time. This commit therefore forces scheduling-clock interrupts within these loops. While in the area, this commit also prevents rcu_torture_reader()'s occasional timed sleeps from delaying shutdown. [ paulmck: Apply Joel Fernandes TICK_DEP_MASK_RCU->TICK_DEP_BIT_RCU fix. ] Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu')
-rw-r--r--kernel/rcu/rcutorture.c16
1 files changed, 10 insertions, 6 deletions
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 3c9feca1eab1..ab61f5c1353b 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -44,6 +44,7 @@
#include <linux/sched/debug.h>
#include <linux/sched/sysctl.h>
#include <linux/oom.h>
+#include <linux/tick.h>
#include "rcu.h"
@@ -1363,15 +1364,15 @@ rcu_torture_reader(void *arg)
set_user_nice(current, MAX_NICE);
if (irqreader && cur_ops->irq_capable)
timer_setup_on_stack(&t, rcu_torture_timer, 0);
-
+ tick_dep_set_task(current, TICK_DEP_BIT_RCU);
do {
if (irqreader && cur_ops->irq_capable) {
if (!timer_pending(&t))
mod_timer(&t, jiffies + 1);
}
- if (!rcu_torture_one_read(&rand))
+ if (!rcu_torture_one_read(&rand) && !torture_must_stop())
schedule_timeout_interruptible(HZ);
- if (time_after(jiffies, lastsleep)) {
+ if (time_after(jiffies, lastsleep) && !torture_must_stop()) {
schedule_timeout_interruptible(1);
lastsleep = jiffies + 10;
}
@@ -1383,6 +1384,7 @@ rcu_torture_reader(void *arg)
del_timer_sync(&t);
destroy_timer_on_stack(&t);
}
+ tick_dep_clear_task(current, TICK_DEP_BIT_RCU);
torture_kthread_stopping("rcu_torture_reader");
return 0;
}
@@ -1729,10 +1731,10 @@ static void rcu_torture_fwd_prog_cond_resched(unsigned long iter)
// Real call_rcu() floods hit userspace, so emulate that.
if (need_resched() || (iter & 0xfff))
schedule();
- } else {
- // No userspace emulation: CB invocation throttles call_rcu()
- cond_resched();
+ return;
}
+ // No userspace emulation: CB invocation throttles call_rcu()
+ cond_resched();
}
/*
@@ -1865,6 +1867,7 @@ static void rcu_torture_fwd_prog_cr(void)
cver = READ_ONCE(rcu_torture_current_version);
gps = cur_ops->get_gp_seq();
rcu_launder_gp_seq_start = gps;
+ tick_dep_set_task(current, TICK_DEP_BIT_RCU);
while (time_before(jiffies, stopat) &&
!shutdown_time_arrived() &&
!READ_ONCE(rcu_fwd_emergency_stop) && !torture_must_stop()) {
@@ -1911,6 +1914,7 @@ static void rcu_torture_fwd_prog_cr(void)
rcu_torture_fwd_cb_hist();
}
schedule_timeout_uninterruptible(HZ); /* Let CBs drain. */
+ tick_dep_clear_task(current, TICK_DEP_BIT_RCU);
WRITE_ONCE(rcu_fwd_cb_nodelay, false);
}