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 AC39139448D; Wed, 4 Mar 2026 22:01:34 +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=1772661694; cv=none; b=pJlcY/Ba4QR/RYbG5tgFLbJo32X0lAGP2M1k/Yhtvvo4P+A6RszMtczU4sKv9E77VGSabjf7SXoPYTqQ8y4Z9TIyrOes0Yf3u/9lodKY/2DuwB52HJp/N8zMe9NunOnMg80zual4TRZcBhfROuBEfLNeszZ17co+4X8XxUx2Bqk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772661694; c=relaxed/simple; bh=dZxQtbm3OaBgjS8OWahf629wh02F8Cz6JCupgGfsK2I=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=iSu5+W5pbT3XKZpmzm1pMChm5jB3emM8bo1HO1+6Xn/JnJc1m/q3jssJoBAPMcOg/jQFMwamoCySMsLuAmj/n215FHNpmp1/SM0gMH7xMGTxklJCAuuViT+VNnaNbuF3z6D715fn+ys4uqU/La5en7UJVgcnXvEAGXTlXSzNeOc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=BALFtlHw; 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="BALFtlHw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 18993C4CEF7; Wed, 4 Mar 2026 22:01:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772661694; bh=dZxQtbm3OaBgjS8OWahf629wh02F8Cz6JCupgGfsK2I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BALFtlHwgy4PPoAoQpKOyAI4PCmbwPwbm6tYkF7vPpgqLToOZ5cwTP1Wu2KfuSAdE Gf5AC7VeQQ7xbML6p9Hqx5SYrMkuRp+2wU/LcsBqXr+ewoygP0ZZUN1M5hWy7LYpsw 2aMLJoy/SNvyFz5hah5qCVxqjGg+l4DXSNz/+8X9xlxp156jRyq0kjpPxrL0zTe4R7 KDYcK0d08rFGN9Hp1qYCxmXQthWF40ph2Wm6VlPeeAOhlyhLyqNnkdmZgAhvFGFQwy v/3AH5R1sXTaAyUZc463T9DZAY8ZTtqQ4DALJBVIIo4c5yuJ+FIjw2YJxKBJRM4/Er 5ypEbRwWwzyNw== From: Tejun Heo To: linux-kernel@vger.kernel.org, sched-ext@lists.linux.dev Cc: void@manifault.com, arighi@nvidia.com, changwoo@igalia.com, emil@etsalapatis.com, Tejun Heo Subject: [PATCH 13/34] sched_ext: Refactor task init/exit helpers Date: Wed, 4 Mar 2026 12:00:58 -1000 Message-ID: <20260304220119.4095551-14-tj@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260304220119.4095551-1-tj@kernel.org> References: <20260304220119.4095551-1-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 | 68 ++++++++++++++++++++++++++++++---------------- 1 file changed, 45 insertions(+), 23 deletions(-) diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index 349f94864e51..4280b639a6e0 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -3111,16 +3111,15 @@ 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; int ret; p->scx.disallow = false; if (SCX_HAS_OP(sch, init_task)) { struct scx_init_task_args args = { - SCX_INIT_TASK_ARGS_CGROUP(tg) + SCX_INIT_TASK_ARGS_CGROUP(task_group(p)) .fork = fork, }; @@ -3132,8 +3131,6 @@ 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]", @@ -3163,13 +3160,27 @@ 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; @@ -3195,16 +3206,20 @@ 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); @@ -3222,9 +3237,9 @@ static void scx_disable_task(struct task_struct *p) WARN_ON_ONCE(p->scx.flags & SCX_TASK_IN_CUSTODY); } -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, }; @@ -3241,7 +3256,7 @@ 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); @@ -3251,6 +3266,13 @@ 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); } @@ -3286,7 +3308,7 @@ 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; @@ -3310,7 +3332,7 @@ 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); } } @@ -3330,7 +3352,7 @@ 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); } @@ -3389,7 +3411,7 @@ 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); } } @@ -3421,7 +3443,7 @@ static void switching_to_scx(struct rq *rq, struct task_struct *p) if (task_dead_and_done(p)) return; - scx_enable_task(p); + scx_enable_task(sch, p); /* * set_cpus_allowed_scx() is not called while @p is associated with a @@ -3437,7 +3459,7 @@ static void switched_from_scx(struct rq *rq, struct task_struct *p) if (task_dead_and_done(p)) return; - 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) {} @@ -4681,7 +4703,7 @@ 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); @@ -4710,7 +4732,7 @@ 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); @@ -5595,7 +5617,7 @@ static void scx_root_enable_workfn(struct kthread_work *work) 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); -- 2.53.0