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| author | Paul E. McKenney <paulmck@kernel.org> | 2020-07-02 14:15:33 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2020-08-24 18:38:37 -0700 |
| commit | a7c072ef26644b632241d549869f10f8d2dd3b5c (patch) | |
| tree | add86b114c6cd0b36a5f7626fff3b7fc15203652 /kernel | |
| parent | de77d4da54d10df97d265e7e99112bfc2fef7d4a (diff) | |
| download | linux-stable-a7c072ef26644b632241d549869f10f8d2dd3b5c.tar.gz linux-stable-a7c072ef26644b632241d549869f10f8d2dd3b5c.tar.bz2 linux-stable-a7c072ef26644b632241d549869f10f8d2dd3b5c.zip | |
scftorture: Block scftorture_invoker() kthreads for offline CPUs
Currently, CPU-hotplug operations might result in all but two
of (say) 100 CPUs being offline, which in turn might result in
false-positive diagnostics due to overload. This commit therefore
causes scftorture_invoker() kthreads for offline CPUs to loop blocking
for 200 milliseconds at a time, thus continuously adjusting the number
of threads to match the number of online CPUs.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/scftorture.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/kernel/scftorture.c b/kernel/scftorture.c index d9c01c722e2a..04d3a4279413 100644 --- a/kernel/scftorture.c +++ b/kernel/scftorture.c @@ -381,11 +381,14 @@ static void scftorture_invoke_one(struct scf_statistics *scfp, struct torture_ra // smp_call_function() family of functions. static int scftorture_invoker(void *arg) { + int cpu; DEFINE_TORTURE_RANDOM(rand); struct scf_statistics *scfp = (struct scf_statistics *)arg; + bool was_offline = false; VERBOSE_SCFTORTOUT("scftorture_invoker %d: task started", scfp->cpu); - set_cpus_allowed_ptr(current, cpumask_of(scfp->cpu % nr_cpu_ids)); + cpu = scfp->cpu % nr_cpu_ids; + set_cpus_allowed_ptr(current, cpumask_of(cpu)); set_user_nice(current, MAX_NICE); if (holdoff) schedule_timeout_interruptible(holdoff * HZ); @@ -408,6 +411,14 @@ static int scftorture_invoker(void *arg) do { scftorture_invoke_one(scfp, &rand); + while (cpu_is_offline(cpu) && !torture_must_stop()) { + schedule_timeout_interruptible(HZ / 5); + was_offline = true; + } + if (was_offline) { + set_cpus_allowed_ptr(current, cpumask_of(cpu)); + was_offline = false; + } } while (!torture_must_stop()); VERBOSE_SCFTORTOUT("scftorture_invoker %d ended", scfp->cpu); |