diff options
| author | Xuewen Yan <xuewen.yan@unisoc.com> | 2025-03-03 18:52:39 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-06-19 15:39:22 +0200 |
| commit | 74c84deec50a9c1dc66dcffcd1a0e32262b6701f (patch) | |
| tree | 076bb6a87dac01d1341debbbe4bc28dc853bbde9 | |
| parent | c5a15c74124ae1649323d2a4e856e942c1ca9b1e (diff) | |
sched/fair: Fixup wake_up_sync() vs DELAYED_DEQUEUE
[ Upstream commit aa3ee4f0b7541382c9f6f43f7408d73a5d4f4042 ]
Delayed dequeued feature keeps a sleeping task enqueued until its
lag has elapsed. As a result, it stays also visible in rq->nr_running.
So when in wake_affine_idle(), we should use the real running-tasks
in rq to check whether we should place the wake-up task to
current cpu.
On the other hand, add a helper function to return the nr-delayed.
Fixes: 152e11f6df29 ("sched/fair: Implement delayed dequeue")
Signed-off-by: Xuewen Yan <xuewen.yan@unisoc.com>
Reviewed-and-tested-by: Tianchen Ding <dtcccc@linux.alibaba.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20250303105241.17251-2-xuewen.yan@unisoc.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | kernel/sched/fair.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 0fb9bf995a47..0c04ed414852 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7196,6 +7196,11 @@ static bool dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags) return true; } +static inline unsigned int cfs_h_nr_delayed(struct rq *rq) +{ + return (rq->cfs.h_nr_queued - rq->cfs.h_nr_runnable); +} + #ifdef CONFIG_SMP /* Working cpumask for: sched_balance_rq(), sched_balance_newidle(). */ @@ -7357,8 +7362,12 @@ wake_affine_idle(int this_cpu, int prev_cpu, int sync) if (available_idle_cpu(this_cpu) && cpus_share_cache(this_cpu, prev_cpu)) return available_idle_cpu(prev_cpu) ? prev_cpu : this_cpu; - if (sync && cpu_rq(this_cpu)->nr_running == 1) - return this_cpu; + if (sync) { + struct rq *rq = cpu_rq(this_cpu); + + if ((rq->nr_running - cfs_h_nr_delayed(rq)) == 1) + return this_cpu; + } if (available_idle_cpu(prev_cpu)) return prev_cpu; |