From nobody Sat Feb 7 06:54:24 2026 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) (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 39A8F171C7 for ; Fri, 22 Mar 2024 08:16:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.187 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711095364; cv=none; b=hT9A+vTzXS6CyQS8GaI7KLdY+MJNj1Qfb4q85M3+ULoNgtfUer5q66j0FS054sPZzc1yqQok412uSPeQfASt2MkF/BB58wtkv8yfOQ3CCwy2oS1xc9SaCjrJUnQYn74zASljVvfGTCJcyN43t8YRW7wMABe2lGtweX57J1hc4bQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711095364; c=relaxed/simple; bh=qX9W0ylN2sPwDi09Z/FTDNjcpHGUfiTpvS/c2SCQe0Y=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=N9Fbxp8MVtSDiKyNY6yyxyluwJkQ/Ad2USMsehtEwbDeioemCEmdUEAL7H6bDq6+MniKHQDzPrJxcz59pZ+pMMUcLOKB+q/0JXdG+zzdjAqNeAb3YOshJ86ue20FoonVVND0I16LZkW3Fu5kY3M7Iw0ITB7EZ+ylnHEgtTOCdfk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.187 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.162.254]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4V1FTB0l9VztQXK; Fri, 22 Mar 2024 16:13:34 +0800 (CST) Received: from dggpeml500018.china.huawei.com (unknown [7.185.36.186]) by mail.maildlp.com (Postfix) with ESMTPS id B951218007C; Fri, 22 Mar 2024 16:15:52 +0800 (CST) Received: from octopus.huawei.com (10.67.174.191) by dggpeml500018.china.huawei.com (7.185.36.186) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.35; Fri, 22 Mar 2024 16:15:52 +0800 From: Zhang Qiao To: , , , , , , , , , CC: , , , Zhang Qiao Subject: [PATCH] sched: Improve the accuracy of sched_stat_wait statistics for rt and dl Date: Fri, 22 Mar 2024 16:15:21 +0800 Message-ID: <20240322081521.2687856-1-zhangqiao22@huawei.com> X-Mailer: git-send-email 2.18.0.huawei.25 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To dggpeml500018.china.huawei.com (7.185.36.186) Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Where commit b9c88f752268 ("sched/fair: Improve the accuracy of sched_stat_wait statistics") fixed a wrong scenairio for cfs schedstat. This wrong scenario is also present for the RT task. For avoiding this scenario, add wait_start check in __update_stats_wait_end(); Signed-off-by: Zhang Qiao --- kernel/sched/fair.c | 9 --------- kernel/sched/stats.c | 11 ++++++++++- 2 files changed, 10 insertions(+), 10 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 6a16129f9a5c..36c81fe0086b 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1208,15 +1208,6 @@ update_stats_wait_end_fair(struct cfs_rq *cfs_rq, st= ruct sched_entity *se) =20 stats =3D __schedstats_from_se(se); =20 - /* - * When the sched_schedstat changes from 0 to 1, some sched se - * maybe already in the runqueue, the se->statistics.wait_start - * will be 0.So it will let the delta wrong. We need to avoid this - * scenario. - */ - if (unlikely(!schedstat_val(stats->wait_start))) - return; - if (entity_is_task(se)) p =3D task_of(se); =20 diff --git a/kernel/sched/stats.c b/kernel/sched/stats.c index 857f837f52cb..7077eb490c09 100644 --- a/kernel/sched/stats.c +++ b/kernel/sched/stats.c @@ -20,8 +20,17 @@ void __update_stats_wait_start(struct rq *rq, struct tas= k_struct *p, void __update_stats_wait_end(struct rq *rq, struct task_struct *p, struct sched_statistics *stats) { - u64 delta =3D rq_clock(rq) - schedstat_val(stats->wait_start); + u64 delta; =20 + /* + * When the sched_schedstat changes from 0 to 1, some sched se + * maybe already in the runqueue, the stats->wait_start will be 0. + * So it will let the delta wrong. We need to avoid this scenario. + */ + if (unlikely(!schedstat_val(stats->wait_start))) + return; + + delta =3D rq_clock(rq) - schedstat_val(stats->wait_start); if (p) { if (task_on_rq_migrating(p)) { /* --=20 2.18.0.huawei.25