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| author | Paul E. McKenney <paulmck@kernel.org> | 2024-01-03 19:59:25 +0100 |
|---|---|---|
| committer | Boqun Feng <boqun.feng@gmail.com> | 2024-02-14 17:00:57 +0100 |
| commit | fd2a749d3f4f7ff0129af1a2c2685faca407ea54 (patch) | |
| tree | 7d24676d39d06fc42b40f8a7d48a063acb24fa25 /kernel/rcu | |
| parent | srcu: Improve comments about acceleration leak (diff) | |
| download | linux-fd2a749d3f4f7ff0129af1a2c2685faca407ea54.tar.xz linux-fd2a749d3f4f7ff0129af1a2c2685faca407ea54.zip | |
rcutorture: Suppress rtort_pipe_count warnings until after stalls
Currently, if rcu_torture_writer() sees fewer than ten grace periods
having elapsed during a call to stutter_wait() that actually waited,
the rtort_pipe_count warning is emitted. This has worked well for
a long time. Except that the rcutorture TREE07 scenario now does a
short-term 14-second RCU CPU stall, which can most definitely case
false-positive rtort_pipe_count warnings.
This commit therefore changes rcu_torture_writer() to compute the
full expected holdoff and stall duration, and to refuse to report any
rtort_pipe_count warnings until after all stalls have completed.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Diffstat (limited to 'kernel/rcu')
| -rw-r--r-- | kernel/rcu/rcutorture.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 7567ca8e743c..45d6b4c3d199 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -1368,9 +1368,13 @@ rcu_torture_writer(void *arg) struct rcu_torture *rp; struct rcu_torture *old_rp; static DEFINE_TORTURE_RANDOM(rand); + unsigned long stallsdone = jiffies; bool stutter_waited; unsigned long ulo[NUM_ACTIVE_RCU_POLL_OLDSTATE]; + // If a new stall test is added, this must be adjusted. + if (stall_cpu_holdoff + stall_gp_kthread + stall_cpu) + stallsdone += (stall_cpu_holdoff + stall_gp_kthread + stall_cpu + 60) * HZ; VERBOSE_TOROUT_STRING("rcu_torture_writer task started"); if (!can_expedite) pr_alert("%s" TORTURE_FLAG @@ -1576,11 +1580,11 @@ rcu_torture_writer(void *arg) !atomic_read(&rcu_fwd_cb_nodelay) && !cur_ops->slow_gps && !torture_must_stop() && - boot_ended) + boot_ended && + time_after(jiffies, stallsdone)) for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) if (list_empty(&rcu_tortures[i].rtort_free) && - rcu_access_pointer(rcu_torture_current) != - &rcu_tortures[i]) { + rcu_access_pointer(rcu_torture_current) != &rcu_tortures[i]) { tracing_off(); show_rcu_gp_kthreads(); WARN(1, "%s: rtort_pipe_count: %d\n", __func__, rcu_tortures[i].rtort_pipe_count); @@ -2441,7 +2445,8 @@ static struct notifier_block rcu_torture_stall_block = { /* * CPU-stall kthread. It waits as specified by stall_cpu_holdoff, then - * induces a CPU stall for the time specified by stall_cpu. + * induces a CPU stall for the time specified by stall_cpu. If a new + * stall test is added, stallsdone in rcu_torture_writer() must be adjusted. */ static int rcu_torture_stall(void *args) { |