From nobody Mon Feb 9 11:47:12 2026 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 A5A341AB522 for ; Tue, 13 Aug 2024 22:50:39 +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=1723589441; cv=none; b=DGJEUVOw4XtY0l9/RPIP4DJhhXArWmpcGHxCoav9R6jSvb0JgzTZ65m9UJKlXddnodlVrbVQ05RTtmh9WKxQuilhc/Gf2qw/lieFKMyHvwYunpk4TO5FpfuX27ujW1wJvZazaSjRQd8eKYiIA3YtHnRPCeYJhYwN9bijBEpIVN4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723589441; c=relaxed/simple; bh=i8a8A/VUcSd/UmUIDuxLs+UOZIAkea+Jb6r9d160Nu4=; h=Message-Id:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=I9yKuzK0/rRpJLZG/qLl7Uh6AgCzwMs9dMHO4FkKWVYxprugB53hNa1THMOfXY1KTSZyD20do9boQjt73qQMy1KSx7PG7HFNqzXOU5G3pPyBc6/+zzGLxDPLsbGlKYcUMB7VRmyleEAFV7+/u5XRVE9TaADw8EFLPd5NDL5YoXM= 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=m39qjLeK; 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="m39qjLeK" 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=5S1HikZ9q6jC+sQEh9d0ZhP7cP9EgQzT1qMsQkQw+30=; b=m39qjLeKFe/0SPTBUNhSlnNVyb HFvuJuOb4SzhJWYsksysTQHB4wjK4FVHCNyjBe6hB+wtAr1ruUP8ZH3WbVaOc5y73md0lRIlRKFfU flU5b8VcbRpwtdaP5mArzA4XvIVrgWTRCSVuPEv298B+gOaiUKYR3qcSFDLpPt1vXj+QviuHveMSP TRxSlFkIJhbzzWEc5AtMTkL99VAif0/FqxkAqH0uDF+rYXEZxZxgkKdzcw8PSWCqh1dt3s6ai6Ncm 9OX+FoeDjPIfBeBU60QS5fsMrXMy6oTxTplxpeS/DUrLXt0IR5wEsGBH64N+LV1EQEzXF20qC+lru K/EvXtRw==; 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 1se0LW-00000007s11-0aZo; Tue, 13 Aug 2024 22:50:30 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 0) id 39750301D1D; Wed, 14 Aug 2024 00:50:29 +0200 (CEST) Message-Id: <20240813224015.837303391@infradead.org> User-Agent: quilt/0.65 Date: Wed, 14 Aug 2024 00:25:51 +0200 From: Peter Zijlstra To: mingo@kernel.org, tj@kernel.org, void@manifault.com Cc: 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, joelaf@google.com Subject: [PATCH 3/9] sched: Clean up DL server vs core sched References: <20240813222548.049744955@infradead.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Abide by the simple rule: pick_next_task() :=3D pick_task() + set_next_task(.first =3D true) This allows us to trivially get rid of server_pick_next() and things collapse nicely. Signed-off-by: Peter Zijlstra (Intel) --- include/linux/sched.h | 1 - kernel/sched/deadline.c | 18 +++++++----------- kernel/sched/fair.c | 13 +------------ kernel/sched/sched.h | 1 - 4 files changed, 8 insertions(+), 25 deletions(-) --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -692,7 +692,6 @@ struct sched_dl_entity { */ struct rq *rq; dl_server_has_tasks_f server_has_tasks; - dl_server_pick_f server_pick_next; dl_server_pick_f server_pick_task; =20 #ifdef CONFIG_RT_MUTEXES --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1665,12 +1665,10 @@ void dl_server_stop(struct sched_dl_enti =20 void dl_server_init(struct sched_dl_entity *dl_se, struct rq *rq, dl_server_has_tasks_f has_tasks, - dl_server_pick_f pick_next, dl_server_pick_f pick_task) { dl_se->rq =3D rq; dl_se->server_has_tasks =3D has_tasks; - dl_se->server_pick_next =3D pick_next; dl_se->server_pick_task =3D pick_task; } =20 @@ -2410,9 +2408,8 @@ static struct sched_dl_entity *pick_next /* * __pick_next_task_dl - Helper to pick the next -deadline task to run. * @rq: The runqueue to pick the next task from. - * @peek: If true, just peek at the next task. Only relevant for dlserver. */ -static struct task_struct *__pick_next_task_dl(struct rq *rq, bool peek) +static struct task_struct *__pick_task_dl(struct rq *rq) { struct sched_dl_entity *dl_se; struct dl_rq *dl_rq =3D &rq->dl; @@ -2426,10 +2423,7 @@ static struct task_struct *__pick_next_t WARN_ON_ONCE(!dl_se); =20 if (dl_server(dl_se)) { - if (IS_ENABLED(CONFIG_SMP) && peek) - p =3D dl_se->server_pick_task(dl_se); - else - p =3D dl_se->server_pick_next(dl_se); + p =3D dl_se->server_pick_task(dl_se); if (!p) { dl_se->dl_yielded =3D 1; update_curr_dl_se(rq, dl_se, 0); @@ -2446,7 +2440,7 @@ static struct task_struct *__pick_next_t #ifdef CONFIG_SMP static struct task_struct *pick_task_dl(struct rq *rq) { - return __pick_next_task_dl(rq, true); + return __pick_task_dl(rq); } #endif =20 @@ -2454,11 +2448,13 @@ static struct task_struct *pick_next_tas { struct task_struct *p; =20 - p =3D __pick_next_task_dl(rq, false); + p =3D __pick_task_dl(rq); if (!p) return p; =20 - if (!p->dl_server) + if (p->dl_server) + p->sched_class->set_next_task(rq, p, true); + else set_next_task_dl(rq, p, true); =20 return p; --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -8860,16 +8860,7 @@ static bool fair_server_has_tasks(struct =20 static struct task_struct *fair_server_pick_task(struct sched_dl_entity *d= l_se) { -#ifdef CONFIG_SMP return pick_task_fair(dl_se->rq); -#else - return NULL; -#endif -} - -static struct task_struct *fair_server_pick_next(struct sched_dl_entity *d= l_se) -{ - return pick_next_task_fair(dl_se->rq, NULL, NULL); } =20 void fair_server_init(struct rq *rq) @@ -8878,9 +8869,7 @@ void fair_server_init(struct rq *rq) =20 init_dl_entity(dl_se); =20 - dl_server_init(dl_se, rq, fair_server_has_tasks, fair_server_pick_next, - fair_server_pick_task); - + dl_server_init(dl_se, rq, fair_server_has_tasks, fair_server_pick_task); } =20 /* --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -362,7 +362,6 @@ extern void dl_server_start(struct sched extern void dl_server_stop(struct sched_dl_entity *dl_se); extern void dl_server_init(struct sched_dl_entity *dl_se, struct rq *rq, dl_server_has_tasks_f has_tasks, - dl_server_pick_f pick_next, dl_server_pick_f pick_task); =20 extern void dl_server_update_idle_time(struct rq *rq,