From b038383526d8c7883ea0486dd1911102b6dda414 Mon Sep 17 00:00:00 2001 From: Wanwu Li Date: Mon, 31 Aug 2026 18:11:41 +0800 Subject: [PATCH] sched/fair: Use cfs_rq->h_curr in distribute_cfs_runtime() distribute_cfs_runtime() refreshes the rq clock and accounts elapsed runtime with update_curr() before redistributing bandwidth, but gates this on cfs_rq->curr. Since commit 85570f10a4c6 ("sched/eevdf: Move to a single runqueue") cfs_rq->curr is only maintained on the root cfs_rq, so for the cgroup cfs_rqs it walks, the check never fires and the refresh is dead code. Use cfs_rq->h_curr, the per-level current entity, restoring the intended behaviour: only refresh when something is actually running at the throttled level, i.e. within the deferred throttle window. Without this, runtime consumed by a still-running task of the throttled hierarchy is not docked before redistribution; unthrottle_cfs_rq() catches up unconditionally since commit 28ad5427682b ("sched/fair: Call update_curr() before unthrottling the hierarchy"), so this is not a correctness hole today, but the refresh the check was written for is gone. Fixes: 85570f10a4c6 ("sched/eevdf: Move to a single runqueue") Signed-off-by: Wanwu Li Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Aaron Lu Tested-by: Aaron Lu Link: https://patch.msgid.link/20260831101141.391382-3-liwanwu@kylinos.cn --- kernel/sched/fair.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 73797d661486..97021a5033fb 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7192,7 +7192,7 @@ static bool distribute_cfs_runtime(struct cfs_bandwidth *cfs_b) if (!list_empty(&cfs_rq->throttled_csd_list)) continue; - if (cfs_rq->curr) { + if (cfs_rq->h_curr) { update_rq_clock(rq); update_curr(cfs_rq); }