From nobody Fri Apr 10 12:39:04 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3DC3DC32793 for ; Tue, 23 Aug 2022 11:42:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1358456AbiHWLlx (ORCPT ); Tue, 23 Aug 2022 07:41:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48888 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1357886AbiHWLg2 (ORCPT ); Tue, 23 Aug 2022 07:36:28 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 02169910A8; Tue, 23 Aug 2022 02:27:38 -0700 (PDT) Date: Tue, 23 Aug 2022 09:27:35 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1661246857; 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=FZtTtlT3Ek/uhaDXZRzX2YYiBkkyi0eObGUW5WssUak=; b=EL8AwDik2Z8YQTjls+4PjCIyLUrauWHi5D5jPiijPyTmlUrT12wy8ZZRjvvmdibfhFgP65 /an8m5vdHTMc6AP8MEQbU4SP83BtLZa60YNTpnnWPGreJ1hdZZt/8mTeYj11fsTupPWqHU zofDha3UVezb3/ytu7qKQ18mqlM7D9b65bQ2MURgYaGm4+fKsyO+xJHHZpCXSJq8MHN2Q0 UlwThh3m1uKUA1PHiwYw22zHTjN8eGcmMTz05ESARQTPGrtVGtZmGATeYTOZyc2CKcP/5b g+457C1EH4e3tXJ2XMG1TUfGQtF5Hokv1CMqwKx3oiefnELSdRd8lrBq8+jyJQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1661246857; 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=FZtTtlT3Ek/uhaDXZRzX2YYiBkkyi0eObGUW5WssUak=; b=ey58db+XBW5cHO493UGnXTZZzCHIvIIkA/05da1wtXhXZcVby5PnMYvweNarQx3Jhw3liW SNyHCp1AyBXdN1Bg== From: "tip-bot2 for Chengming Zhou" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: sched/core] sched/fair: Remove redundant cpu_cgrp_subsys->fork() Cc: Chengming Zhou , "Peter Zijlstra (Intel)" , Vincent Guittot , Dietmar Eggemann , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20220818124805.601-3-zhouchengming@bytedance.com> References: <20220818124805.601-3-zhouchengming@bytedance.com> MIME-Version: 1.0 Message-ID: <166124685590.401.15944614410686814398.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the sched/core branch of tip: Commit-ID: 39c4261191bf05e7eb310f852980a6d0afe5582a Gitweb: https://git.kernel.org/tip/39c4261191bf05e7eb310f852980a6d0a= fe5582a Author: Chengming Zhou AuthorDate: Thu, 18 Aug 2022 20:47:58 +08:00 Committer: Peter Zijlstra CommitterDate: Tue, 23 Aug 2022 11:01:17 +02:00 sched/fair: Remove redundant cpu_cgrp_subsys->fork() We use cpu_cgrp_subsys->fork() to set task group for the new fair task in cgroup_post_fork(). Since commit b1e8206582f9 ("sched: Fix yet more sched_fork() races") has already set_task_rq() for the new fair task in sched_cgroup_fork(), so cpu_cgrp_subsys->fork() can be removed. cgroup_can_fork() --> pin parent's sched_task_group sched_cgroup_fork() __set_task_cpu() set_task_rq() cgroup_post_fork() ss->fork() :=3D cpu_cgroup_fork() sched_change_group(..., TASK_SET_GROUP) task_set_group_fair() set_task_rq() --> can be removed After this patch's change, task_change_group_fair() only need to care about task cgroup migration, make the code much simplier. Signed-off-by: Chengming Zhou Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Vincent Guittot Reviewed-by: Dietmar Eggemann Link: https://lore.kernel.org/r/20220818124805.601-3-zhouchengming@bytedanc= e.com --- kernel/sched/core.c | 27 ++++----------------------- kernel/sched/fair.c | 23 +---------------------- kernel/sched/sched.h | 5 +---- 3 files changed, 6 insertions(+), 49 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 64c0899..e74e79f 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -481,8 +481,7 @@ sched_core_dequeue(struct rq *rq, struct task_struct *p= , int flags) { } * p->se.load, p->rt_priority, * p->dl.dl_{runtime, deadline, period, flags, bw, density} * - sched_setnuma(): p->numa_preferred_nid - * - sched_move_task()/ - * cpu_cgroup_fork(): p->sched_task_group + * - sched_move_task(): p->sched_task_group * - uclamp_update_active() p->uclamp* * * p->state <- TASK_*: @@ -10114,7 +10113,7 @@ void sched_release_group(struct task_group *tg) spin_unlock_irqrestore(&task_group_lock, flags); } =20 -static void sched_change_group(struct task_struct *tsk, int type) +static void sched_change_group(struct task_struct *tsk) { struct task_group *tg; =20 @@ -10130,7 +10129,7 @@ static void sched_change_group(struct task_struct *= tsk, int type) =20 #ifdef CONFIG_FAIR_GROUP_SCHED if (tsk->sched_class->task_change_group) - tsk->sched_class->task_change_group(tsk, type); + tsk->sched_class->task_change_group(tsk); else #endif set_task_rq(tsk, task_cpu(tsk)); @@ -10161,7 +10160,7 @@ void sched_move_task(struct task_struct *tsk) if (running) put_prev_task(rq, tsk); =20 - sched_change_group(tsk, TASK_MOVE_GROUP); + sched_change_group(tsk); =20 if (queued) enqueue_task(rq, tsk, queue_flags); @@ -10239,23 +10238,6 @@ static void cpu_cgroup_css_free(struct cgroup_subs= ys_state *css) sched_unregister_group(tg); } =20 -/* - * This is called before wake_up_new_task(), therefore we really only - * have to set its group bits, all the other stuff does not apply. - */ -static void cpu_cgroup_fork(struct task_struct *task) -{ - struct rq_flags rf; - struct rq *rq; - - rq =3D task_rq_lock(task, &rf); - - update_rq_clock(rq); - sched_change_group(task, TASK_SET_GROUP); - - task_rq_unlock(rq, task, &rf); -} - static int cpu_cgroup_can_attach(struct cgroup_taskset *tset) { struct task_struct *task; @@ -11121,7 +11103,6 @@ struct cgroup_subsys cpu_cgrp_subsys =3D { .css_released =3D cpu_cgroup_css_released, .css_free =3D cpu_cgroup_css_free, .css_extra_stat_show =3D cpu_extra_stat_show, - .fork =3D cpu_cgroup_fork, .can_attach =3D cpu_cgroup_can_attach, .attach =3D cpu_cgroup_attach, .legacy_cftypes =3D cpu_legacy_files, diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index a3b0f8b..2c0eb2a 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -11657,15 +11657,7 @@ void init_cfs_rq(struct cfs_rq *cfs_rq) } =20 #ifdef CONFIG_FAIR_GROUP_SCHED -static void task_set_group_fair(struct task_struct *p) -{ - struct sched_entity *se =3D &p->se; - - set_task_rq(p, task_cpu(p)); - se->depth =3D se->parent ? se->parent->depth + 1 : 0; -} - -static void task_move_group_fair(struct task_struct *p) +static void task_change_group_fair(struct task_struct *p) { detach_task_cfs_rq(p); set_task_rq(p, task_cpu(p)); @@ -11677,19 +11669,6 @@ static void task_move_group_fair(struct task_struc= t *p) attach_task_cfs_rq(p); } =20 -static void task_change_group_fair(struct task_struct *p, int type) -{ - switch (type) { - case TASK_SET_GROUP: - task_set_group_fair(p); - break; - - case TASK_MOVE_GROUP: - task_move_group_fair(p); - break; - } -} - void free_fair_sched_group(struct task_group *tg) { int i; diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 4c48221..74130a6 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -2193,11 +2193,8 @@ struct sched_class { =20 void (*update_curr)(struct rq *rq); =20 -#define TASK_SET_GROUP 0 -#define TASK_MOVE_GROUP 1 - #ifdef CONFIG_FAIR_GROUP_SCHED - void (*task_change_group)(struct task_struct *p, int type); + void (*task_change_group)(struct task_struct *p); #endif };