mirror of
https://github.com/brain-hackers/linux-brain.git
synced 2024-06-09 23:36:23 +09:00
527378a0df
[ Upstream commit e98fa02c4f2ea4991dae422ac7e34d102d2f0599 ] There is a race window in which an entity begins throttling before quota is added to the pool, but does not finish throttling until after we have finished with distribute_cfs_runtime(). This entity is not observed by distribute_cfs_runtime() because it was not on the throttled list at the time that distribution was running. This race manifests as rare period-length statlls for such entities. Rather than heavy-weight the synchronization with the progress of distribution, we can fix this by aborting throttling if bandwidth has become available. Otherwise, we immediately add the entity to the throttled list so that it can be observed by a subsequent distribution. Additionally, we can remove the case of adding the throttled entity to the head of the throttled list, and simply always add to the tail. Thanks to 26a8b12747c97, distribute_cfs_runtime() no longer holds onto its own pool of runtime. This means that if we do hit the !assign and distribute_running case, we know that distribution is about to end. Signed-off-by: Paul Turner <pjt@google.com> Signed-off-by: Ben Segall <bsegall@google.com> Signed-off-by: Josh Don <joshdon@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Phil Auld <pauld@redhat.com> Link: https://lkml.kernel.org/r/20200410225208.109717-2-joshdon@google.com Signed-off-by: Sasha Levin <sashal@kernel.org> |
||
|---|---|---|
| .. | ||
| autogroup.c | ||
| autogroup.h | ||
| clock.c | ||
| completion.c | ||
| core.c | ||
| cpuacct.c | ||
| cpudeadline.c | ||
| cpudeadline.h | ||
| cpufreq_schedutil.c | ||
| cpufreq.c | ||
| cpupri.c | ||
| cpupri.h | ||
| cputime.c | ||
| deadline.c | ||
| debug.c | ||
| fair.c | ||
| features.h | ||
| idle.c | ||
| isolation.c | ||
| loadavg.c | ||
| Makefile | ||
| membarrier.c | ||
| pelt.c | ||
| pelt.h | ||
| psi.c | ||
| rt.c | ||
| sched-pelt.h | ||
| sched.h | ||
| stats.c | ||
| stats.h | ||
| stop_task.c | ||
| swait.c | ||
| topology.c | ||
| wait_bit.c | ||
| wait.c | ||