From nobody Sun Feb 8 13:27:51 2026 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 F319031DD9A; Thu, 16 Oct 2025 09:33:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760607219; cv=none; b=U51QV4qF2CukP9dv1e8cSO8880ZcW/PKFwZFSKfiUkXsoqtaiqZO4icpiOECWYGmyyqBCO9BjwUDeoIHY5o4L4pdtFVlt5GJhIH2gMIwWejImgQFih/tS9MeTD7sOi4S/TNfagZR9Xj1T9HqlCcseyZVL3aG1z7ZPzxY981dF7U= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760607219; c=relaxed/simple; bh=+0Gkamp5W5b8jDXkKPLBkc3GZEJkhnOYEJbjcEVhhb0=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=OCNl59+FDhEqAMhII0jo8nC+0Z88Si0Zo5aC5d4tHfksmpCpMsSKZXXBlOUDCanvofqq01eCOrT2q16OBRdjtICmK/Eonl5XdHVgI+YKDXyoSpug/YMTLNpK7j2uzYD/9m0g5NoJVcSubdewQzGH9JanuHs40Y0dvgWDcaABlxs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=MH7XVEXT; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=L0xoHfxL; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="MH7XVEXT"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="L0xoHfxL" Date: Thu, 16 Oct 2025 09:33:33 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1760607215; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=jsMwV2oJH8ZFwEAQb/Sqc3BkiLMwNhUfhO6KiCBCxVc=; b=MH7XVEXTrZ5NU8CEyYVJWsRgADxnLIZNhkrZQbYLOHnll4W30jTIYdvlU4mL9Qzu/4nvAF m0Hej8Zh5QekuD5mDAGIdOqi0ObN+AcMYJw3VY1iuY9+HlJXFhEUAcFM004Kj6nVJ5pLl6 eQ6Zm+iA9XXhO8WuWp6dtefy64cS+HQDqSMPnEW7V+AW1Xo5bmsJmeyvg+yaNA7UV53owN AMW4LbkqdFUkYJ3dIlB7Ur6bm0QngLtwr0dLMuYS7vvSntA8QA1Wb7uqSM+7ZDHmOr8bHV vB8tRWc9HMelV/ljLVeHd46V78nMrCLuJThk2CQA+WYpXiEz/WhT9KeP2mVWJg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1760607215; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=jsMwV2oJH8ZFwEAQb/Sqc3BkiLMwNhUfhO6KiCBCxVc=; b=L0xoHfxLA673h1Q71tXkYhXQoEXrCcQDvbH+K5Yg7zQ0HEuPVzcHVafxEqg91V7RGeLN4F DUBdYOEjxZ8gbBAw== From: "tip-bot2 for Peter Zijlstra" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: sched/core] sched: Move sched_class::prio_changed() into the change pattern Cc: Tejun Heo , "Peter Zijlstra (Intel)" , Juri Lelli , Vincent Guittot , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20251006104527.083607521@infradead.org> References: <20251006104527.083607521@infradead.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <176060721397.709179.10063752274577762847.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The following commit has been merged into the sched/core branch of tip: Commit-ID: 6455ad5346c9cf755fa9dda6e326c4028fb3c853 Gitweb: https://git.kernel.org/tip/6455ad5346c9cf755fa9dda6e326c4028= fb3c853 Author: Peter Zijlstra AuthorDate: Fri, 01 Nov 2024 14:16:10 +01:00 Committer: Peter Zijlstra CommitterDate: Thu, 16 Oct 2025 11:13:52 +02:00 sched: Move sched_class::prio_changed() into the change pattern Move sched_class::prio_changed() into the change pattern. And while there, extend it with sched_class::get_prio() in order to fix the deadline sitation. Suggested-by: Tejun Heo Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Juri Lelli Acked-by: Tejun Heo Acked-by: Vincent Guittot --- kernel/sched/core.c | 24 +++++++++++++----------- kernel/sched/deadline.c | 20 +++++++++++--------- kernel/sched/ext.c | 8 +------- kernel/sched/fair.c | 8 ++++++-- kernel/sched/idle.c | 5 ++++- kernel/sched/rt.c | 5 ++++- kernel/sched/sched.h | 7 ++++--- kernel/sched/stop_task.c | 5 ++++- kernel/sched/syscalls.c | 9 --------- 9 files changed, 47 insertions(+), 44 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index bd2c551..4a4dbce 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2169,12 +2169,6 @@ inline int task_curr(const struct task_struct *p) return cpu_curr(task_cpu(p)) =3D=3D p; } =20 -void check_prio_changed(struct rq *rq, struct task_struct *p, int oldprio) -{ - if (oldprio !=3D p->prio || dl_task(p)) - p->sched_class->prio_changed(rq, p, oldprio); -} - void wakeup_preempt(struct rq *rq, struct task_struct *p, int flags) { struct task_struct *donor =3D rq->donor; @@ -7400,9 +7394,6 @@ void rt_mutex_setprio(struct task_struct *p, struct t= ask_struct *pi_task) p->sched_class =3D next_class; p->prio =3D prio; } - - if (!(queue_flag & DEQUEUE_CLASS)) - check_prio_changed(rq, p, oldprio); out_unlock: /* Avoid rq from going away on us: */ preempt_disable(); @@ -10855,6 +10846,13 @@ struct sched_change_ctx *sched_change_begin(struct= task_struct *p, unsigned int=20 .running =3D task_current_donor(rq, p), }; =20 + if (!(flags & DEQUEUE_CLASS)) { + if (p->sched_class->get_prio) + ctx->prio =3D p->sched_class->get_prio(rq, p); + else + ctx->prio =3D p->prio; + } + if (ctx->queued) dequeue_task(rq, p, flags); if (ctx->running) @@ -10881,6 +10879,10 @@ void sched_change_end(struct sched_change_ctx *ctx) if (ctx->running) set_next_task(rq, p); =20 - if ((ctx->flags & ENQUEUE_CLASS) && p->sched_class->switched_to) - p->sched_class->switched_to(rq, p); + if (ctx->flags & ENQUEUE_CLASS) { + if (p->sched_class->switched_to) + p->sched_class->switched_to(rq, p); + } else { + p->sched_class->prio_changed(rq, p, ctx->prio); + } } diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index fd147a7..1f94994 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -3042,23 +3042,24 @@ static void switched_to_dl(struct rq *rq, struct ta= sk_struct *p) } } =20 +static u64 get_prio_dl(struct rq *rq, struct task_struct *p) +{ + return p->dl.deadline; +} + /* * If the scheduling parameters of a -deadline task changed, * a push or pull operation might be needed. */ -static void prio_changed_dl(struct rq *rq, struct task_struct *p, - int oldprio) +static void prio_changed_dl(struct rq *rq, struct task_struct *p, u64 old_= deadline) { if (!task_on_rq_queued(p)) return; =20 - /* - * This might be too much, but unfortunately - * we don't have the old deadline value, and - * we can't argue if the task is increasing - * or lowering its prio, so... - */ - if (!rq->dl.overloaded) + if (p->dl.deadline =3D=3D old_deadline) + return; + + if (dl_time_before(old_deadline, p->dl.deadline)) deadline_queue_pull_task(rq); =20 if (task_current_donor(rq, p)) { @@ -3113,6 +3114,7 @@ DEFINE_SCHED_CLASS(dl) =3D { .task_tick =3D task_tick_dl, .task_fork =3D task_fork_dl, =20 + .get_prio =3D get_prio_dl, .prio_changed =3D prio_changed_dl, .switched_from =3D switched_from_dl, .switched_to =3D switched_to_dl, diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index b0a1e2a..ad371b6 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -2961,7 +2961,7 @@ static void reweight_task_scx(struct rq *rq, struct t= ask_struct *p, p, p->scx.weight); } =20 -static void prio_changed_scx(struct rq *rq, struct task_struct *p, int old= prio) +static void prio_changed_scx(struct rq *rq, struct task_struct *p, u64 old= prio) { } =20 @@ -3926,9 +3926,6 @@ static void scx_disable_workfn(struct kthread_work *w= ork) p->sched_class =3D new_class; } =20 - if (!(queue_flags & DEQUEUE_CLASS)) - check_prio_changed(task_rq(p), p, p->prio); - scx_exit_task(p); } scx_task_iter_stop(&sti); @@ -4675,9 +4672,6 @@ static int scx_enable(struct sched_ext_ops *ops, stru= ct bpf_link *link) p->sched_class =3D new_class; } =20 - if (!(queue_flags & DEQUEUE_CLASS)) - check_prio_changed(task_rq(p), p, p->prio); - put_task_struct(p); } scx_task_iter_stop(&sti); diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 6c462e4..77a713e 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -13150,11 +13150,14 @@ static void task_fork_fair(struct task_struct *p) * the current task. */ static void -prio_changed_fair(struct rq *rq, struct task_struct *p, int oldprio) +prio_changed_fair(struct rq *rq, struct task_struct *p, u64 oldprio) { if (!task_on_rq_queued(p)) return; =20 + if (p->prio =3D=3D oldprio) + return; + if (rq->cfs.nr_queued =3D=3D 1) return; =20 @@ -13166,8 +13169,9 @@ prio_changed_fair(struct rq *rq, struct task_struct= *p, int oldprio) if (task_current_donor(rq, p)) { if (p->prio > oldprio) resched_curr(rq); - } else + } else { wakeup_preempt(rq, p, 0); + } } =20 #ifdef CONFIG_FAIR_GROUP_SCHED diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c index f02dced..dee6e01 100644 --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -504,8 +504,11 @@ static void switching_to_idle(struct rq *rq, struct ta= sk_struct *p) } =20 static void -prio_changed_idle(struct rq *rq, struct task_struct *p, int oldprio) +prio_changed_idle(struct rq *rq, struct task_struct *p, u64 oldprio) { + if (p->prio =3D=3D oldprio) + return; + BUG(); } =20 diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 6b2e811..c2347e4 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -2437,11 +2437,14 @@ static void switched_to_rt(struct rq *rq, struct ta= sk_struct *p) * us to initiate a push or pull. */ static void -prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio) +prio_changed_rt(struct rq *rq, struct task_struct *p, u64 oldprio) { if (!task_on_rq_queued(p)) return; =20 + if (p->prio =3D=3D oldprio) + return; + if (task_current_donor(rq, p)) { /* * If our priority decreases while running, we diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index e3f4215..bcde43d 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -2451,8 +2451,10 @@ struct sched_class { =20 void (*reweight_task)(struct rq *this_rq, struct task_struct *task, const struct load_weight *lw); + + u64 (*get_prio) (struct rq *this_rq, struct task_struct *task); void (*prio_changed) (struct rq *this_rq, struct task_struct *task, - int oldprio); + u64 oldprio); =20 unsigned int (*get_rr_interval)(struct rq *rq, struct task_struct *task); @@ -3877,8 +3879,6 @@ extern void set_load_weight(struct task_struct *p, bo= ol update_load); extern void enqueue_task(struct rq *rq, struct task_struct *p, int flags); extern bool dequeue_task(struct rq *rq, struct task_struct *p, int flags); =20 -extern void check_prio_changed(struct rq *rq, struct task_struct *p, int o= ldprio); - extern struct balance_callback *splice_balance_callbacks(struct rq *rq); extern void balance_callbacks(struct rq *rq, struct balance_callback *head= ); =20 @@ -3899,6 +3899,7 @@ extern void balance_callbacks(struct rq *rq, struct b= alance_callback *head); * the task's queueing state is idempotent across the operation. */ struct sched_change_ctx { + u64 prio; struct task_struct *p; int flags; bool queued; diff --git a/kernel/sched/stop_task.c b/kernel/sched/stop_task.c index fcc4c54..73aa8de 100644 --- a/kernel/sched/stop_task.c +++ b/kernel/sched/stop_task.c @@ -81,8 +81,11 @@ static void switching_to_stop(struct rq *rq, struct task= _struct *p) } =20 static void -prio_changed_stop(struct rq *rq, struct task_struct *p, int oldprio) +prio_changed_stop(struct rq *rq, struct task_struct *p, u64 oldprio) { + if (p->prio =3D=3D oldprio) + return; + BUG(); /* how!?, what priority? */ } =20 diff --git a/kernel/sched/syscalls.c b/kernel/sched/syscalls.c index 6583faf..20af564 100644 --- a/kernel/sched/syscalls.c +++ b/kernel/sched/syscalls.c @@ -95,12 +95,6 @@ void set_user_nice(struct task_struct *p, long nice) old_prio =3D p->prio; p->prio =3D effective_prio(p); } - - /* - * If the task increased its priority or is running and - * lowered its priority, then reschedule its CPU: - */ - p->sched_class->prio_changed(rq, p, old_prio); } EXPORT_SYMBOL(set_user_nice); =20 @@ -706,9 +700,6 @@ change: } } =20 - if (!(queue_flags & DEQUEUE_CLASS)) - check_prio_changed(rq, p, oldprio); - /* Avoid rq from going away on us: */ preempt_disable(); head =3D splice_balance_callbacks(rq);