From nobody Thu Dec 18 08:27:24 2025 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 A5D2315A868 for ; Wed, 24 Jul 2024 14:23:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721831009; cv=none; b=toCXk2QnyUXk8ss9agX3CwIeeCzJONS1EsVGdmxFRhLfHnMmFt+1GwWt9gti7yY7YbgFA6WVAjLipM+hOAbng8DhjKkguELpWGcVL10zXor5Tft02wKLNysIMPul8ibkvLNrUo97muEn3sD9OKJSWjWyHXp2uGHrjDpYH/XORwA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721831009; c=relaxed/simple; bh=s4HNljaPZJLJD6YDsI7FLSF9XPk6iswpMqvouyoqiVo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Fg6Fy9F8dZJkkAOJJpsQ4M5o3KzlIMaU1BFR7mlgB6cP+B1dbjBc7oaDVGfwPcYCbiNnvXWysuqDNfYC1r5ExPWs3NOkxof8y3s+3TMPx8qITm7stJrklk/sYNMGSdmF/F6Y62tt2oot8g9qyBi2JLSKNFGULIZdMrhFUHrcOiU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=UcDT1P7w; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="UcDT1P7w" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1721831006; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ZK+LHXm7qy0Qg5Y629tT+uBJ6vtvH0lHMF8fm1/ksuU=; b=UcDT1P7wiMaoVlN7bBYeMS92203AGOrv59mLFSRRFZOx/eEDBG+wcyzrMdlhFNPykEan7w 17hXET31h6Mo2FCliMu1gpwwvk/AvK3B5TlNe1Spc/+rhsSJP1PEmsUSjrJh6ULjowADzG i1kL5mrAFY/gvng4shqG2+hIvBc6cUk= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-376-mZeYtixNODibNF_EnDzVTg-1; Wed, 24 Jul 2024 10:23:21 -0400 X-MC-Unique: mZeYtixNODibNF_EnDzVTg-1 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 2084B1955BF2; Wed, 24 Jul 2024 14:23:18 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.96.134.38]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id ADC9219560AE; Wed, 24 Jul 2024 14:23:13 +0000 (UTC) From: Wander Lairson Costa To: Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , linux-kernel@vger.kernel.org (open list:SCHEDULER) Cc: Wander Lairson Costa Subject: [PATCH v2 2/2] sched/deadline: Consolidate Timer Cancellation Date: Wed, 24 Jul 2024 11:22:48 -0300 Message-ID: <20240724142253.27145-3-wander@redhat.com> In-Reply-To: <20240724142253.27145-1-wander@redhat.com> References: <20240724142253.27145-1-wander@redhat.com> 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 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Content-Type: text/plain; charset="utf-8" After commit b58652db66c9 ("sched/deadline: Fix task_struct reference leak"), I identified additional calls to hrtimer_try_to_cancel that might also require a dl_server check. It remains unclear whether this omission was intentional or accidental in those contexts. This patch consolidates the timer cancellation logic into dedicated functions, ensuring consistent behavior across all calls. Additionally, it reduces code duplication and improves overall code cleanliness. Note the use of the __always_inline keyword. In some instances, we have a task_struct pointer, dereference the dl member, and then use the container_of macro to retrieve the task_struct pointer again. By inlining the code, the compiler can potentially optimize out this redundant round trip. Signed-off-by: Wander Lairson Costa --- kernel/sched/deadline.c | 44 ++++++++++++++++++++++++++--------------- 1 file changed, 28 insertions(+), 16 deletions(-) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 312e8fa7ce94..b509ac4f3f6d 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -320,6 +320,29 @@ void sub_running_bw(struct sched_dl_entity *dl_se, str= uct dl_rq *dl_rq) __sub_running_bw(dl_se->dl_bw, dl_rq); } =20 +static __always_inline +void cancel_dl_timer(struct sched_dl_entity *dl_se, struct hrtimer *timer) +{ + /* + * If the timer callback was running (hrtimer_try_to_cancel =3D=3D -1), + * it will eventually call put_task_struct(). + */ + if (hrtimer_try_to_cancel(timer) =3D=3D 1 && !dl_server(dl_se)) + put_task_struct(dl_task_of(dl_se)); +} + +static __always_inline +void cancel_replenish_timer(struct sched_dl_entity *dl_se) +{ + cancel_dl_timer(dl_se, &dl_se->dl_timer); +} + +static __always_inline +void cancel_inactive_timer(struct sched_dl_entity *dl_se) +{ + cancel_dl_timer(dl_se, &dl_se->inactive_timer); +} + static void dl_change_utilization(struct task_struct *p, u64 new_bw) { struct rq *rq; @@ -340,8 +363,7 @@ static void dl_change_utilization(struct task_struct *p= , u64 new_bw) * will not touch the rq's active utilization, * so we are still safe. */ - if (hrtimer_try_to_cancel(&p->dl.inactive_timer) =3D=3D 1) - put_task_struct(p); + cancel_inactive_timer(&p->dl); } __sub_rq_bw(p->dl.dl_bw, &rq->dl); __add_rq_bw(new_bw, &rq->dl); @@ -490,10 +512,7 @@ static void task_contending(struct sched_dl_entity *dl= _se, int flags) * will not touch the rq's active utilization, * so we are still safe. */ - if (hrtimer_try_to_cancel(&dl_se->inactive_timer) =3D=3D 1) { - if (!dl_server(dl_se)) - put_task_struct(dl_task_of(dl_se)); - } + cancel_inactive_timer(dl_se); } else { /* * Since "dl_non_contending" is not set, the @@ -1805,13 +1824,8 @@ static void enqueue_task_dl(struct rq *rq, struct ta= sk_struct *p, int flags) * The replenish timer needs to be canceled. No * problem if it fires concurrently: boosted threads * are ignored in dl_task_timer(). - * - * If the timer callback was running (hrtimer_try_to_cancel =3D=3D -1), - * it will eventually call put_task_struct(). */ - if (hrtimer_try_to_cancel(&p->dl.dl_timer) =3D=3D 1 && - !dl_server(&p->dl)) - put_task_struct(p); + cancel_replenish_timer(&p->dl); p->dl.dl_throttled =3D 0; } } else if (!dl_prio(p->normal_prio)) { @@ -1976,8 +1990,7 @@ static void migrate_task_rq_dl(struct task_struct *p,= int new_cpu __maybe_unused * will not touch the rq's active utilization, * so we are still safe. */ - if (hrtimer_try_to_cancel(&p->dl.inactive_timer) =3D=3D 1) - put_task_struct(p); + cancel_inactive_timer(&p->dl); } sub_rq_bw(&p->dl, &rq->dl); rq_unlock(rq, &rf); @@ -2732,8 +2745,7 @@ static void switched_from_dl(struct rq *rq, struct ta= sk_struct *p) */ static void switched_to_dl(struct rq *rq, struct task_struct *p) { - if (hrtimer_try_to_cancel(&p->dl.inactive_timer) =3D=3D 1) - put_task_struct(p); + cancel_inactive_timer(&p->dl); =20 /* * In case a task is setscheduled to SCHED_DEADLINE we need to keep --=20 2.45.2