From: Peter Zijlstra Date: Thu, 15 Jan 2026 08:27:22 +0000 (+0100) Subject: sched/deadline: Use ENQUEUE_MOVE to allow priority change X-Git-Tag: v6.19-rc6~12^2 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=627cc25f84466d557d86e5dc67b43a4eea604c80;p=thirdparty%2Flinux.git sched/deadline: Use ENQUEUE_MOVE to allow priority change Pierre reported hitting balance callback warnings for deadline tasks after commit 6455ad5346c9 ("sched: Move sched_class::prio_changed() into the change pattern"). It turns out that DEQUEUE_SAVE+ENQUEUE_RESTORE does not preserve DL priority and subsequently trips a balance pass -- where one was not expected. From discussion with Juri and Luca, the purpose of this clause was to deal with tasks new to DL and all those sites will have MOVE set (as well as CLASS, but MOVE is move conservative at this point). Per the previous patches MOVE is audited to always run the balance callbacks, so switch enqueue_dl_entity() to use MOVE for this case. Fixes: 6455ad5346c9 ("sched: Move sched_class::prio_changed() into the change pattern") Reported-by: Pierre Gondois Signed-off-by: Peter Zijlstra (Intel) Tested-by: Pierre Gondois Tested-by: Juri Lelli Link: https://patch.msgid.link/20260114130528.GB831285@noisy.programming.kicks-ass.net --- diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 5d6f3cced740..c509f2e7d69d 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -2214,7 +2214,7 @@ enqueue_dl_entity(struct sched_dl_entity *dl_se, int flags) update_dl_entity(dl_se); } else if (flags & ENQUEUE_REPLENISH) { replenish_dl_entity(dl_se); - } else if ((flags & ENQUEUE_RESTORE) && + } else if ((flags & ENQUEUE_MOVE) && !is_dl_boosted(dl_se) && dl_time_before(dl_se->deadline, rq_clock(rq_of_dl_se(dl_se)))) { setup_new_dl_entity(dl_se);