From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2C47676C61 for ; Sat, 27 Jul 2024 11:02:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722078149; cv=none; b=UKJtWcxLso3P2IgJiwrH3hDi8RaX+7x2ihUlD/My29T1fIls81LwtqKAWkxNXJJc71G9tNDrsRWZbOGyarTJKBcNQpBZ4Lfj+Q2Y7EHKtPk3v8aA9XBgShwB5i1WCpV3E3aDFd26ffTwvyDQSx4fg8MLFUPFWOCaJUUX5aTPiKc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722078149; c=relaxed/simple; bh=UjpvSUfzFnwK76Bs7wFDqK5xuHrje2T2yPFj2mB7/4k=; h=Message-Id:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=F9RCfedleXc0QloM7dAkr2gt8Zw7gpHyEYonq9PxRNR4UkdZgxSPRR7W5pmLjyQFxViPIi4IyfqM9Pl1boU+CbHyyWQGcJ5meTof9JGxw4gDoJTfeTUVGpgeoSk3W/IDJVrXZFE+Vw36056uEWvQBMIj02hfwr8gPgwomFUvfZ4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=T0Hhd/lQ; arc=none smtp.client-ip=90.155.92.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="T0Hhd/lQ" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-Id:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=Wypbsa8TcX0ssA9GJe6UbYub1r9G8dWt4safnPicCkk=; b=T0Hhd/lQOs7Nfrx2Ye5Q9fSmpc lpxF2w2pZaksqrXeSTruK8hhZYbdZk0p1DLXVp8KHbnu/tHEXPr8vMf9Cc5A0r3eZH7Vm7px/Hbgg Xcn2/jF7GengsO6phxM8NuVbEckbcNjl2yv8Z7rCqbCKG2SkeqBS6p2Hn0KS0VJOOV1IbJxb0qqvp +rEg+C8EYPugVEl07WtVECS/EDCLrmIbNtFOvN/EKYJwklvbRovgOL7oebc3QwcMH6R0Bndgdjydu PWe1v9PFsNtEU2JyvRvDvE6z6+qo6C337HfQQy0CSUXMRtJHcKPcyIYVDKoc7QBE3YWY7zYZgulHM HAL+NF0A==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.97.1 #2 (Red Hat Linux)) id 1sXfBg-00000004QMm-1exh; Sat, 27 Jul 2024 11:02:20 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 0) id C696D306155; Sat, 27 Jul 2024 13:02:06 +0200 (CEST) Message-Id: <20240727105029.747330118@infradead.org> User-Agent: quilt/0.65 Date: Sat, 27 Jul 2024 12:27:45 +0200 From: Peter Zijlstra To: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, linux-kernel@vger.kernel.org Cc: kprateek.nayak@amd.com, wuyun.abel@bytedance.com, youssefesmat@chromium.org, tglx@linutronix.de, efault@gmx.de Subject: [PATCH 13/24] sched/fair: Prepare pick_next_task() for delayed dequeue References: <20240727102732.960974693@infradead.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Delayed dequeue's natural end is when it gets picked again. Ensure pick_next_task() knows what to do with delayed tasks. Note, this relies on the earlier patch that made pick_next_task() state invariant -- it will restart the pick on dequeue, because obviously the just dequeued task is no longer eligible. Signed-off-by: Peter Zijlstra (Intel) --- kernel/sched/fair.c | 23 +++++++++++++++++++---- 1 file changed, 19 insertions(+), 4 deletions(-) --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -5453,6 +5453,8 @@ set_next_entity(struct cfs_rq *cfs_rq, s se->prev_sum_exec_runtime = se->sum_exec_runtime; } +static int dequeue_entities(struct rq *rq, struct sched_entity *se, int flags); + /* * Pick the next process, keeping these things in mind, in this order: * 1) keep things fair between processes/task groups @@ -5461,16 +5463,27 @@ set_next_entity(struct cfs_rq *cfs_rq, s * 4) do not run the "skip" process, if something else is available */ static struct sched_entity * -pick_next_entity(struct cfs_rq *cfs_rq) +pick_next_entity(struct rq *rq, struct cfs_rq *cfs_rq) { /* * Enabling NEXT_BUDDY will affect latency but not fairness. */ if (sched_feat(NEXT_BUDDY) && - cfs_rq->next && entity_eligible(cfs_rq, cfs_rq->next)) + cfs_rq->next && entity_eligible(cfs_rq, cfs_rq->next)) { + /* ->next will never be delayed */ + SCHED_WARN_ON(cfs_rq->next->sched_delayed); return cfs_rq->next; + } + + struct sched_entity *se = pick_eevdf(cfs_rq); + if (se->sched_delayed) { + dequeue_entities(rq, se, DEQUEUE_SLEEP | DEQUEUE_DELAYED); + SCHED_WARN_ON(se->sched_delayed); + SCHED_WARN_ON(se->on_rq); - return pick_eevdf(cfs_rq); + return NULL; + } + return se; } static bool check_cfs_rq_runtime(struct cfs_rq *cfs_rq); @@ -8478,7 +8491,9 @@ static struct task_struct *pick_task_fai if (unlikely(check_cfs_rq_runtime(cfs_rq))) goto again; - se = pick_next_entity(cfs_rq); + se = pick_next_entity(rq, cfs_rq); + if (!se) + goto again; cfs_rq = group_cfs_rq(se); } while (cfs_rq);