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| author |   Paul E. McKenney <paulmck@kernel.org> | 2020-09-01 16:58:41 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2020-11-06 17:13:48 -0800 |
| commit | 19012b786ecccb29a9fa20c4ec0a67e2cdfbc010 (patch) | |
| tree | a4c362ff79e925b3f63dc1ea03218d7d0fdae6eb /drivers/dma-buf | |
| parent | locktorture: Track time of last ->writeunlock() (diff) | |
| download | linux-dev-19012b786ecccb29a9fa20c4ec0a67e2cdfbc010.tar.xz linux-dev-19012b786ecccb29a9fa20c4ec0a67e2cdfbc010.zip | |
torture: Periodically pause in stutter_wait()
Running locktorture scenario LOCK05 results in hangs:
tools/testing/selftests/rcutorture/bin/kvm.sh --allcpus --torture lock --duration 3 --configs LOCK05
The lock_torture_writer() kthreads set themselves to MAX_NICE while
running SCHED_OTHER. Other locktorture kthreads run at default niceness,
also SCHED_OTHER. This results in these other locktorture kthreads
indefinitely preempting the lock_torture_writer() kthreads. Note that
the cond_resched() in the stutter_wait() function's loop is ineffective
because this scenario is built with CONFIG_PREEMPT=y.
It is not clear that such indefinite preemption is supposed to happen, but
in the meantime this commit prevents kthreads running in stutter_wait()
from being completely CPU-bound, thus allowing the other threads to get
some CPU in a timely fashion. This commit also uses hrtimers to provide
very short sleeps to avoid degrading the sudden-on testing that stutter
is supposed to provide.
Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'drivers/dma-buf')
0 files changed, 0 insertions, 0 deletions