From nobody Wed Nov 5 00:39:41 2025 Received: from mail-pj1-f73.google.com (mail-pj1-f73.google.com [209.85.216.73]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 08B2A18787A for ; Tue, 9 Jul 2024 20:32:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.73 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720557161; cv=none; b=sk8U1HU8Ll2YPKS/MIJ8NreAizH4hfP5WSmRiliTKfQk4vpr5+GC8pEpI5r1Tvnbx8WqVxndcqHUlXMZ8vmqcVlsKjzP+Ja8M5uqszmxMYAPLoDuRVR/u9FJPX/kzdoQxRrfaWwt//ncj0Mt/D7CWWRaIGbGWP/uyxBAW5swaIs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720557161; c=relaxed/simple; bh=OdboL8GRjZ9HaNPDORv6f99DqVqCLARn8M9yns8iW10=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=NZotO+NYPBwnVLgEQLtpkL8cv1S0W2VUEwZzhdANWDsKeGt0p1gNA1D7TNXI2NAZv0YmyinvDCM9ClJ0o/SYcTrj66oWj5pQVwY/jUHdvIs0Fz2o0H58ZgU0BqUYQKOlnVglZ9X/SlyuzKc1DRmNk+Js1lbpvILrDRNuUxQvWJ0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--jstultz.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=s6QjC69J; arc=none smtp.client-ip=209.85.216.73 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--jstultz.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="s6QjC69J" Received: by mail-pj1-f73.google.com with SMTP id 98e67ed59e1d1-2c95f737113so5418308a91.0 for ; Tue, 09 Jul 2024 13:32:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1720557159; x=1721161959; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=2+x+zlwEFkDOcEBJWqLmqHwwAqtu5VuIJvpoq5xrn34=; b=s6QjC69J/O1Mv7fjBxyGWCT6lKzY6Qew2CusBhxk5qVWrmZ/sy9pNEv1ZsUduCayDj 7lMnBCsonuv4aZ1oHdYKcB5e7ubanVJSKT+jwa2iiCUmq/QDn9DClC2aYiU1UKqQia5W oy1DBi0AmDa/lrx76yJsUk8AfMlD7aZTgyi08g/j4jsAVybEVUWR53aEJeDBVtZXITkW KqrEMVd1Wyt0VC0kgAlBLwx08A9Ha3/DdPBy2Q4SSEPYVHsU1r8QEEMPC9QDrjJFzcUI UsOYH2ur8e0/Cz6WLe3awyprfDNwwhTpKZOaIvgcVTYD7pd/9/Hd2OWPKjM6HTwwRCET wygA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1720557159; x=1721161959; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=2+x+zlwEFkDOcEBJWqLmqHwwAqtu5VuIJvpoq5xrn34=; b=W7MAVy9sc7LdZkXNrvEPOYRJhMbuha4uZTCfa/5GrVsDOm0kfZiBi55qZLG7MGaEKK LmTClCLq4YZ46V6W+FvTDKL4ouBGJBaVTRyyF/UThGk6G9EceJNAH8aa7XF1/24CK0ng C4VNivIYt81CcQZoIy7akqUrqgya3iZswbDBOJq9eLH11TphmtPKmlp7Wg8iwwVUU+zb BjLqmU8Aa4x0/87PQfnhiQcZq1QYUXPbs+rPlEAcGr8Tzpf+v+nMS7lUULUtdRAq8sft GT84gMGMyd3XvjJcG7wM0dYGUDgNoPpW+59HyV+dbSkYFJJZaAm6VScOZhffyebcWKSm HaTQ== X-Gm-Message-State: AOJu0YxLWu49OaRpWzNsdVzr73CAtQHh9rEdcVhOpRZkYCNSj3KxYFNi /5/Hup47DB4NfCQF3vNbzXSQbPRZa2fwIm/Q9oFWQ7wvo8GuCbiTi81+iuKhnzlLaf2mYuYMYwr qpg23NasU5Lx8rq27B6PuPEC1ZAnpxbzoMv/KWvKDBn5rELUOhjv5DXt5FK2NJk80u71pTncojD zYjz0jM3gLGhqb2tzC9yFWgOoIedUUvCFs4syPcyB5d4aH X-Google-Smtp-Source: AGHT+IFFC0Vp1N3md7SxhD+JLWl5slCFlb5hK6ZHAGLfzOORUrqcGP4Bk8LB46ia8JbxDjJuWLDE4ifCoONQ X-Received: from jstultz-noogler2.c.googlers.com ([fda3:e722:ac3:cc00:24:72f4:c0a8:600]) (user=jstultz job=sendgmr) by 2002:a17:90b:1917:b0:2c9:75c6:32d8 with SMTP id 98e67ed59e1d1-2ca35be805dmr83893a91.1.1720557158836; Tue, 09 Jul 2024 13:32:38 -0700 (PDT) Date: Tue, 9 Jul 2024 13:31:49 -0700 In-Reply-To: <20240709203213.799070-1-jstultz@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240709203213.799070-1-jstultz@google.com> X-Mailer: git-send-email 2.45.2.993.g49e7a77208-goog Message-ID: <20240709203213.799070-7-jstultz@google.com> Subject: [PATCH v11 6/7] sched: Split out __schedule() deactivate task logic into a helper From: John Stultz To: LKML Cc: John Stultz , Joel Fernandes , Qais Yousef , Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Valentin Schneider , Steven Rostedt , Ben Segall , Zimuzo Ezeozue , Youssef Esmat , Mel Gorman , Will Deacon , Waiman Long , Boqun Feng , "Paul E. McKenney" , Metin Kaya , Xuewen Yan , K Prateek Nayak , Thomas Gleixner , Daniel Lezcano , kernel-team@android.com, Metin Kaya Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" As we're going to re-use the deactivation logic, split it into a helper. Cc: Joel Fernandes Cc: Qais Yousef Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Juri Lelli Cc: Vincent Guittot Cc: Dietmar Eggemann Cc: Valentin Schneider Cc: Steven Rostedt Cc: Ben Segall Cc: Zimuzo Ezeozue Cc: Youssef Esmat Cc: Mel Gorman Cc: Will Deacon Cc: Waiman Long Cc: Boqun Feng Cc: "Paul E. McKenney" Cc: Metin Kaya Cc: Xuewen Yan Cc: K Prateek Nayak Cc: Thomas Gleixner Cc: Daniel Lezcano Cc: kernel-team@android.com Signed-off-by: John Stultz Tested-by: K Prateek Nayak Tested-by: Metin Kaya Reviewed-by: Metin Kaya Reviewed-by: Qais Yousef --- v6: * Define function as static to avoid "no previous prototype" warnings as Reported-by: kernel test robot v7: * Rename state task_state to be more clear, as suggested by Metin Kaya v11: * Return early to simplify indentation, and drop unused bool return (will be introduced later when its needed) as sugggested by Qais. --- kernel/sched/core.c | 71 +++++++++++++++++++++++++++------------------ 1 file changed, 42 insertions(+), 29 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 5e63dbcbc1f0..029e7ecf5ea9 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6566,6 +6566,47 @@ pick_next_task(struct rq *rq, struct task_struct *pr= ev, struct rq_flags *rf) # define SM_MASK_PREEMPT SM_PREEMPT #endif =20 +/* + * Helper function for __schedule() + * + * If a task does not have signals pending, deactivate it + * Otherwise marks the task's __state as RUNNING + */ +static void try_to_deactivate_task(struct rq *rq, struct task_struct *p, + unsigned long task_state) +{ + if (signal_pending_state(task_state, p)) { + WRITE_ONCE(p->__state, TASK_RUNNING); + return; + } + + p->sched_contributes_to_load =3D + (task_state & TASK_UNINTERRUPTIBLE) && + !(task_state & TASK_NOLOAD) && + !(task_state & TASK_FROZEN); + + if (p->sched_contributes_to_load) + rq->nr_uninterruptible++; + + /* + * __schedule() ttwu() + * prev_state =3D prev->state; if (p->on_rq && ...) + * if (prev_state) goto out; + * p->on_rq =3D 0; smp_acquire__after_ctrl_dep(); + * p->state =3D TASK_WAKING + * + * Where __schedule() and ttwu() have matching control dependencies. + * + * After this, schedule() must not care about p->state any more. + */ + deactivate_task(rq, p, DEQUEUE_SLEEP | DEQUEUE_NOCLOCK); + + if (p->in_iowait) { + atomic_inc(&rq->nr_iowait); + delayacct_blkio_start(); + } +} + /* * __schedule() is the main scheduler function. * @@ -6659,35 +6700,7 @@ static void __sched notrace __schedule(unsigned int = sched_mode) */ prev_state =3D READ_ONCE(prev->__state); if (!(sched_mode & SM_MASK_PREEMPT) && prev_state) { - if (signal_pending_state(prev_state, prev)) { - WRITE_ONCE(prev->__state, TASK_RUNNING); - } else { - prev->sched_contributes_to_load =3D - (prev_state & TASK_UNINTERRUPTIBLE) && - !(prev_state & TASK_NOLOAD) && - !(prev_state & TASK_FROZEN); - - if (prev->sched_contributes_to_load) - rq->nr_uninterruptible++; - - /* - * __schedule() ttwu() - * prev_state =3D prev->state; if (p->on_rq && ...) - * if (prev_state) goto out; - * p->on_rq =3D 0; smp_acquire__after_ctrl_dep(); - * p->state =3D TASK_WAKING - * - * Where __schedule() and ttwu() have matching control dependencies. - * - * After this, schedule() must not care about p->state any more. - */ - deactivate_task(rq, prev, DEQUEUE_SLEEP | DEQUEUE_NOCLOCK); - - if (prev->in_iowait) { - atomic_inc(&rq->nr_iowait); - delayacct_blkio_start(); - } - } + try_to_deactivate_task(rq, prev, prev_state); switch_count =3D &prev->nvcsw; } =20 --=20 2.45.2.993.g49e7a77208-goog