From: Qian Cai cai@lca.pw
[ Upstream commit 763a9ec06c409dcde2a761aac4bb83ff3938e0b3 ]
Commit:
de53fd7aedb1 ("sched/fair: Fix low cpu usage with high throttling by removing expiration of cpu-local slices")
introduced a few compilation warnings:
kernel/sched/fair.c: In function '__refill_cfs_bandwidth_runtime': kernel/sched/fair.c:4365:6: warning: variable 'now' set but not used [-Wunused-but-set-variable] kernel/sched/fair.c: In function 'start_cfs_bandwidth': kernel/sched/fair.c:4992:6: warning: variable 'overrun' set but not used [-Wunused-but-set-variable]
Also, __refill_cfs_bandwidth_runtime() does no longer update the expiration time, so fix the comments accordingly.
Signed-off-by: Qian Cai cai@lca.pw Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Reviewed-by: Ben Segall bsegall@google.com Reviewed-by: Dave Chiluk chiluk+linux@indeed.com Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Peter Zijlstra peterz@infradead.org Cc: Thomas Gleixner tglx@linutronix.de Cc: pauld@redhat.com Fixes: de53fd7aedb1 ("sched/fair: Fix low cpu usage with high throttling by removing expiration of cpu-local slices") Link: https://lkml.kernel.org/r/1566326455-8038-1-git-send-email-cai@lca.pw Signed-off-by: Ingo Molnar mingo@kernel.org --- kernel/sched/fair.c | 19 ++++++------------- 1 file changed, 6 insertions(+), 13 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index cf0f476..e5e8f67 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4305,21 +4305,16 @@ static inline u64 sched_cfs_bandwidth_slice(void) }
/* - * Replenish runtime according to assigned quota and update expiration time. - * We use sched_clock_cpu directly instead of rq->clock to avoid adding - * additional synchronization around rq->lock. + * Replenish runtime according to assigned quota. We use sched_clock_cpu + * directly instead of rq->clock to avoid adding additional synchronization + * around rq->lock. * * requires cfs_b->lock */ void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b) { - u64 now; - - if (cfs_b->quota == RUNTIME_INF) - return; - - now = sched_clock_cpu(smp_processor_id()); - cfs_b->runtime = cfs_b->quota; + if (cfs_b->quota != RUNTIME_INF) + cfs_b->runtime = cfs_b->quota; }
static inline struct cfs_bandwidth *tg_cfs_bandwidth(struct task_group *tg) @@ -4924,15 +4919,13 @@ static void init_cfs_rq_runtime(struct cfs_rq *cfs_rq)
void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b) { - u64 overrun; - lockdep_assert_held(&cfs_b->lock);
if (cfs_b->period_active) return;
cfs_b->period_active = 1; - overrun = hrtimer_forward_now(&cfs_b->period_timer, cfs_b->period); + hrtimer_forward_now(&cfs_b->period_timer, cfs_b->period); hrtimer_start_expires(&cfs_b->period_timer, HRTIMER_MODE_ABS_PINNED); }