From nobody Fri Dec 19 06:17:54 2025 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 E244718623 for ; Wed, 3 Jan 2024 08:09:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="beUiVz5c" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6D8E5C433C7; Wed, 3 Jan 2024 08:09:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1704269345; bh=/P93iDWx0rUgDH9n+aFD3T8XY72jOetnP/Drn34JroI=; h=From:To:Cc:Subject:Date:From; b=beUiVz5cN9puQyNHLSi1W8HtLbj0mt8+Oe8KQOvTgF5f+hxaLd8Qn3fvvWREInjEB yQrg1j/ItpNZLzHW369EOdoi8yPtgAQgl4Z3L9vD4EAincXAYH5fbcXEDr7NIEXtzg A0b+2uXr9gxA/2Bdp62YyhZfaU/07rn+iCLZonqEGZTX7FeQy5gZVA5NoIArOBYegm Tdi+UEJHpA1pOWeErT5W6JR5L7YW+rHQ0VFCouwGrNSfILL+c1OlXKLsL1pPAn8e4c qJ7kQcYry1oFaN3ppL0uT9ghFec8T2ZjgNS6qZs1zA5TT6+9gOXGSFK1UWaJmiOMj/ 15JMMtqnFU9MA== From: alexs@kernel.org To: Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Daniel Bristot de Oliveira , Valentin Schneider , linux-kernel@vger.kernel.org Cc: curuwang@tencent.com, Alex Shi Subject: [PATCH v2] sched/stat: correct the task blocking state Date: Wed, 3 Jan 2024 16:10:42 +0800 Message-ID: <20240103081042.1549189-1-alexs@kernel.org> X-Mailer: git-send-email 2.43.0 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" From: Alex Shi The commit 80ed87c8a9ca ("sched/wait: Introduce TASK_NOLOAD and TASK_IDLE") stopped the idle kthreads from contributing to the load average. However, the idle state time still contributes to the blocked state time instead of the sleep time. As a result, we cannot determine if a task is stopped due to some reasons or if it is idle by its own initiative.=20 Distinguishing between these two states would make the system state clearer and provide us with an opportunity to use the 'D' state of a task as an indicator of latency issues. Originally-from: Curu Wong Signed-off-by: Alex Shi To: linux-kernel@vger.kernel.org To: Valentin Schneider To: Daniel Bristot de Oliveira To: Mel Gorman To: Ben Segall To: Steven Rostedt To: Dietmar Eggemann To: Vincent Guittot To: Juri Lelli To: Peter Zijlstra To: Ingo Molnar --- include/linux/sched.h | 6 ++++++ kernel/sched/deadline.c | 5 +++-- kernel/sched/fair.c | 5 +++-- kernel/sched/rt.c | 5 +++-- 4 files changed, 15 insertions(+), 6 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 292c31697248..002f80291837 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -140,6 +140,12 @@ struct user_event_mm; #define is_special_task_state(state) \ ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD)) =20 +/* blocked task is UNINTERRUPTIBLE but not NOLOAD */ +#define is_blocked_state(state) \ + ((state) & TASK_UNINTERRUPTIBLE && (!((state) & TASK_NOLOAD))) + +#define is_idle_state(state) (((state) & TASK_IDLE) =3D=3D TASK_IDLE) + #ifdef CONFIG_DEBUG_ATOMIC_SLEEP # define debug_normal_state_change(state_value) \ do { \ diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index b28114478b82..99d46affc2aa 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1566,11 +1566,12 @@ update_stats_dequeue_dl(struct dl_rq *dl_rq, struct= sched_dl_entity *dl_se, unsigned int state; =20 state =3D READ_ONCE(p->__state); - if (state & TASK_INTERRUPTIBLE) + /* idle state still accounts into sleep */ + if (state & TASK_INTERRUPTIBLE || is_idle_state(state)) __schedstat_set(p->stats.sleep_start, rq_clock(rq_of_dl_rq(dl_rq))); =20 - if (state & TASK_UNINTERRUPTIBLE) + if (is_blocked_state(state)) __schedstat_set(p->stats.block_start, rq_clock(rq_of_dl_rq(dl_rq))); } diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index d7a3c63a2171..69506253aadf 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1278,10 +1278,11 @@ update_stats_dequeue_fair(struct cfs_rq *cfs_rq, st= ruct sched_entity *se, int fl =20 /* XXX racy against TTWU */ state =3D READ_ONCE(tsk->__state); - if (state & TASK_INTERRUPTIBLE) + /* idle state still accounts into sleep */ + if (state & TASK_INTERRUPTIBLE || is_idle_state(state)) __schedstat_set(tsk->stats.sleep_start, rq_clock(rq_of(cfs_rq))); - if (state & TASK_UNINTERRUPTIBLE) + if (is_blocked_state(state)) __schedstat_set(tsk->stats.block_start, rq_clock(rq_of(cfs_rq))); } diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 6aaf0a3d6081..dd0e381689f8 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -1371,11 +1371,12 @@ update_stats_dequeue_rt(struct rt_rq *rt_rq, struct= sched_rt_entity *rt_se, unsigned int state; =20 state =3D READ_ONCE(p->__state); - if (state & TASK_INTERRUPTIBLE) + /* idle state still accounts into sleep */ + if (state & TASK_INTERRUPTIBLE || is_idle_state(state)) __schedstat_set(p->stats.sleep_start, rq_clock(rq_of_rt_rq(rt_rq))); =20 - if (state & TASK_UNINTERRUPTIBLE) + if (is_blocked_state(state)) __schedstat_set(p->stats.block_start, rq_clock(rq_of_rt_rq(rt_rq))); } --=20 2.43.0