From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 5FC984534BE; Wed, 21 Jan 2026 23:11:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769037115; cv=none; b=cWH2xBXzRe0/1+AIG/y39u1L2R2uZ35vrwgMf6ZqexXsZ8WQzzs6hyJTblle1Qu0fZTUKnaD/lZHz02VjoKyBJLRdF1MuYWYy9MEALGRzesZXKKvlSzs7T6bpVfcbaPT884Akgifkuf0jzsaeAlVvK15dfEfBBlq90dWg5OF9+g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769037115; c=relaxed/simple; bh=Z3y19F6fI9KHCp1/Vo5Gdy7VEMVR9Cl/kby8qMzcq4s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fa+k4nd3S1qQr+snN738fpqPm8KHbegYPnphiqX/L1CyE/CceGZ3R4R3xtCgREsYR+PTn94UPrwrqc+3GDsnIGMBQPr0UJXXUltwbHN21ZhIAWg3/Diuuu8RG/YX6s4DtlHkmTGsvF2oKdueFVNA67ZcyfbfcrCwTzBG9VpYjOg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QqQNrtTF; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="QqQNrtTF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 19A0DC4CEF1; Wed, 21 Jan 2026 23:11:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1769037115; bh=Z3y19F6fI9KHCp1/Vo5Gdy7VEMVR9Cl/kby8qMzcq4s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QqQNrtTFHBMxbgH2VXis/Pp4euGOSJMlWxTSMBz5mjlaUjb83SNuBxkoSTxVDTDz/ SCJ5phDoMsU9Pi+T7ZSsez+28JpB/vuNWERVPwYBXLsjIMhNF207anSn79RUV8GEIX U4M73PxseAgYnBZtZB2G7VZQkFxc2SdA8njhvDzXpKMJFVqBLnvilr/GX0GpT/aEVO DQMDtqHP/d/eYjbcXPieLbdu5HzxjPFg8B/mtUVQCTUxJGMa9gCblO1vUJFFuk/j8k l66TgFcdeLOfhN4UHxwh7VXjOdPBoizzoM9CV1+/ZkPY9kGnVlIzuPeZuF1FiT1HRz Z9p3HTLfOr4mg== From: Tejun Heo To: linux-kernel@vger.kernel.org, sched-ext@lists.linux.dev Cc: void@manifault.com, andrea.righi@linux.dev, changwoo@igalia.com, emil@etsalapatis.com, Tejun Heo Subject: [PATCH 13/34] sched_ext: Refactor task init/exit helpers Date: Wed, 21 Jan 2026 13:11:19 -1000 Message-ID: <20260121231140.832332-14-tj@kernel.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260121231140.832332-1-tj@kernel.org> References: <20260121231140.832332-1-tj@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit - Add the @sch parameter to scx_init_task() and drop @tg as it can be obtained from @p. Separate out __scx_init_task() which does everything except for the task state transition. - Add the @sch parameter to scx_enable_task(). Separate out __scx_enable_task() which does everything except for the task state transition. - Add the @sch parameter to scx_disable_task(). - Rename scx_exit_task() to scx_disable_and_exit_task() and separate out __scx_disable_and_exit_task() which does everything except for the task state transition. While some task state transitions are relocated, no meaningful behavior changes are expected. Signed-off-by: Tejun Heo --- kernel/sched/ext.c | 67 +++++++++++++++++++++++++++++++--------------- 1 file changed, 45 insertions(+), 22 deletions(-) diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index 07cd130f62fb..a834da7701df 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -2987,9 +2987,9 @@ static void scx_set_task_state(struct task_struct *p, enum scx_task_state state) p->scx.flags |= state << SCX_TASK_STATE_SHIFT; } -static int scx_init_task(struct task_struct *p, struct task_group *tg, bool fork) +static int __scx_init_task(struct scx_sched *sch, struct task_struct *p, bool fork) { - struct scx_sched *sch = scx_root; + struct task_group *tg = task_group(p); int ret; p->scx.disallow = false; @@ -3008,8 +3008,6 @@ static int scx_init_task(struct task_struct *p, struct task_group *tg, bool fork } } - scx_set_task_state(p, SCX_TASK_INIT); - if (p->scx.disallow) { if (unlikely(scx_parent(sch))) { scx_error(sch, "non-root ops.init_task() set task->scx.disallow for %s[%d]", @@ -3039,13 +3037,27 @@ static int scx_init_task(struct task_struct *p, struct task_group *tg, bool fork } } - p->scx.flags |= SCX_TASK_RESET_RUNNABLE_AT; return 0; } -static void scx_enable_task(struct task_struct *p) +static int scx_init_task(struct scx_sched *sch, struct task_struct *p, bool fork) +{ + int ret; + + ret = __scx_init_task(sch, p, fork); + if (!ret) { + /* + * While @p's rq is not locked. @p is not visible to the rest of + * SCX yet and it's safe to update the flags and state. + */ + p->scx.flags |= SCX_TASK_RESET_RUNNABLE_AT; + scx_set_task_state(p, SCX_TASK_INIT); + } + return ret; +} + +static void __scx_enable_task(struct scx_sched *sch, struct task_struct *p) { - struct scx_sched *sch = scx_root; struct rq *rq = task_rq(p); u32 weight; @@ -3064,16 +3076,20 @@ static void scx_enable_task(struct task_struct *p) if (SCX_HAS_OP(sch, enable)) SCX_CALL_OP_TASK(sch, SCX_KF_REST, enable, rq, p); - scx_set_task_state(p, SCX_TASK_ENABLED); if (SCX_HAS_OP(sch, set_weight)) SCX_CALL_OP_TASK(sch, SCX_KF_REST, set_weight, rq, p, p->scx.weight); } -static void scx_disable_task(struct task_struct *p) +static void scx_enable_task(struct scx_sched *sch, struct task_struct *p) +{ + __scx_enable_task(sch, p); + scx_set_task_state(p, SCX_TASK_ENABLED); +} + +static void scx_disable_task(struct scx_sched *sch, struct task_struct *p) { - struct scx_sched *sch = scx_root; struct rq *rq = task_rq(p); lockdep_assert_rq_held(rq); @@ -3084,9 +3100,9 @@ static void scx_disable_task(struct task_struct *p) scx_set_task_state(p, SCX_TASK_READY); } -static void scx_exit_task(struct task_struct *p) +static void __scx_disable_and_exit_task(struct scx_sched *sch, + struct task_struct *p) { - struct scx_sched *sch = scx_task_sched(p); struct scx_exit_task_args args = { .cancelled = false, }; @@ -3103,7 +3119,7 @@ static void scx_exit_task(struct task_struct *p) case SCX_TASK_READY: break; case SCX_TASK_ENABLED: - scx_disable_task(p); + scx_disable_task(sch, p); break; default: WARN_ON_ONCE(true); @@ -3113,6 +3129,13 @@ static void scx_exit_task(struct task_struct *p) if (SCX_HAS_OP(sch, exit_task)) SCX_CALL_OP_TASK(sch, SCX_KF_REST, exit_task, task_rq(p), p, &args); +} + +static void scx_disable_and_exit_task(struct scx_sched *sch, + struct task_struct *p) +{ + __scx_disable_and_exit_task(sch, p); + scx_set_task_sched(p, NULL); scx_set_task_state(p, SCX_TASK_NONE); } @@ -3148,7 +3171,7 @@ int scx_fork(struct task_struct *p, struct kernel_clone_args *kargs) percpu_rwsem_assert_held(&scx_fork_rwsem); if (scx_init_task_enabled) { - ret = scx_init_task(p, task_group(p), true); + ret = scx_init_task(scx_root, p, true); if (!ret) scx_set_task_sched(p, scx_root); return ret; @@ -3172,7 +3195,7 @@ void scx_post_fork(struct task_struct *p) struct rq *rq; rq = task_rq_lock(p, &rf); - scx_enable_task(p); + scx_enable_task(scx_task_sched(p), p); task_rq_unlock(rq, p, &rf); } } @@ -3192,7 +3215,7 @@ void scx_cancel_fork(struct task_struct *p) rq = task_rq_lock(p, &rf); WARN_ON_ONCE(scx_get_task_state(p) >= SCX_TASK_READY); - scx_exit_task(p); + scx_disable_and_exit_task(scx_task_sched(p), p); task_rq_unlock(rq, p, &rf); } @@ -3216,7 +3239,7 @@ void sched_ext_dead(struct task_struct *p) struct rq *rq; rq = task_rq_lock(p, &rf); - scx_exit_task(p); + scx_disable_and_exit_task(scx_task_sched(p), p); task_rq_unlock(rq, p, &rf); } } @@ -3242,7 +3265,7 @@ static void switching_to_scx(struct rq *rq, struct task_struct *p) { struct scx_sched *sch = scx_task_sched(p); - scx_enable_task(p); + scx_enable_task(sch, p); /* * set_cpus_allowed_scx() is not called while @p is associated with a @@ -3255,7 +3278,7 @@ static void switching_to_scx(struct rq *rq, struct task_struct *p) static void switched_from_scx(struct rq *rq, struct task_struct *p) { - scx_disable_task(p); + scx_disable_task(scx_task_sched(p), p); } static void wakeup_preempt_scx(struct rq *rq, struct task_struct *p,int wake_flags) {} @@ -4485,7 +4508,7 @@ static void scx_root_disable(struct scx_sched *sch) /* * Shut down cgroup support before tasks so that the cgroup attach path - * doesn't race against scx_exit_task(). + * doesn't race against scx_disable_and_exit_task(). */ scx_cgroup_lock(); scx_cgroup_exit(sch); @@ -4514,7 +4537,7 @@ static void scx_root_disable(struct scx_sched *sch) p->sched_class = new_class; } - scx_exit_task(p); + scx_disable_and_exit_task(scx_task_sched(p), p); } scx_task_iter_stop(&sti); @@ -5379,7 +5402,7 @@ static s32 scx_root_enable(struct sched_ext_ops *ops, struct bpf_link *link) scx_task_iter_unlock(&sti); - ret = scx_init_task(p, task_group(p), false); + ret = scx_init_task(sch, p, false); if (ret) { put_task_struct(p); scx_task_iter_stop(&sti); -- 2.52.0