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| author |   Xuewen Yan <xuewen.yan@unisoc.com> | 2025-03-03 18:52:39 +0800 |
|---|---|---|
| committer |   Peter Zijlstra <peterz@infradead.org> | 2025-05-21 13:57:37 +0200 |
| commit | aa3ee4f0b7541382c9f6f43f7408d73a5d4f4042 (patch) | |
| tree | d299652f5cb375ffacc5aedbf451c8bf3efde80a | |
| parent | sched,livepatch: Untangle cond_resched() and live-patching (diff) | |
| download | wireguard-linux-aa3ee4f0b7541382c9f6f43f7408d73a5d4f4042.tar.xz wireguard-linux-aa3ee4f0b7541382c9f6f43f7408d73a5d4f4042.zip | |
sched/fair: Fixup wake_up_sync() vs DELAYED_DEQUEUE
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
Diffstat (limited to '')
| -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 eb5a2572b4f8..b00f16700f9c 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7193,6 +7193,11 @@ 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(). */ @@ -7354,8 +7359,12 @@ 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; |