From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4A034C4727C for ; Wed, 30 Sep 2020 02:47:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E3F1020773 for ; Wed, 30 Sep 2020 02:47:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="kXwbHsyN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729739AbgI3Crd (ORCPT ); Tue, 29 Sep 2020 22:47:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38010 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729446AbgI3Crd (ORCPT ); Tue, 29 Sep 2020 22:47:33 -0400 Received: from mail-ot1-x344.google.com (mail-ot1-x344.google.com [IPv6:2607:f8b0:4864:20::344]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2CDAEC061755 for ; Tue, 29 Sep 2020 19:47:33 -0700 (PDT) Received: by mail-ot1-x344.google.com with SMTP id y5so381261otg.5 for ; Tue, 29 Sep 2020 19:47:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=sGxrRFYRD0vQg740ZJ2H+rUYx/z6zC5mWNZdnhAeh4U=; b=kXwbHsyNVoI4/G7NNmYs54XNqWBE57wKN3iSoTakXC9LNYp+8QkzrekZzoaQ4d6Qyl QvK6IaX1ksJlYJR7qVzGSQ/gpOrygf6s54dwboiJYJDZ9UhSQsXRDe0f3VPYbXMRNQeo 1D0g1pNk+h2sG42zRLX2uU8jkziKzxAq0phVv7V+t6zw0csFSrN8JlZXuYLpUxnRJbSE iwhIkgrr5vjH/a2Ton3O3qQljZrt4YGSht0hsmy7eRuWC51YjGeHhfVyftD4rgCd2xk5 abfBZwCbVu5O+mh/PTO8zmJprGBegYMGviCckJHDa0s0Q7ejIyzwMGpGvaMv36JMr4eJ jPig== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=sGxrRFYRD0vQg740ZJ2H+rUYx/z6zC5mWNZdnhAeh4U=; b=jQkzMxjj8we0w9qnn9TExLTNbFZJjNSjK2ntAwzoKvn3GNCy2SWWUZR5lUIN8P2GMG MnoFUwqfW5f7oGjkPxhsZXwHYx9jstVkud7ZfaYg3Pp3u556ltyP9rQt5dahhlqVvYD1 edHpOMeS6WYs93XvxXE0mfYeIpj4wD+eSxjM/MmsIIBekj/SFuRKmgPMDpv2fZD2sF/F ALBHBkvAzAKqk2j83uegUE7oPfQeXMG/BzgKpdBqKtkYMdFLdqN806zz+U3WHxnm9LIK MKEB7NX+XGT8v6EhsIQGbri16AM/d7Md3GngJttlgBL+r0PxkjwnXdOK5vHZW7m42z7x 3eOA== X-Gm-Message-State: AOAM533/LHNHQ7BZlJwcBVZrXW9mogNQTsrcUkNvw8Y1+XHblv1FMoXy QUSmbRQGqjj8kvmzbMIZohE= X-Google-Smtp-Source: ABdhPJxpBFCSE8IpHGqUvd0sgt17R9lJP4ky9Glatg1kcOxiLlCPN4Jx/gwNY8S5czJW4EH2gOCUxA== X-Received: by 2002:a9d:3a34:: with SMTP id j49mr194485otc.52.1601434052576; Tue, 29 Sep 2020 19:47:32 -0700 (PDT) Received: from localhost.localdomain ([50.236.19.102]) by smtp.gmail.com with ESMTPSA id k10sm82097ots.60.2020.09.29.19.47.24 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 29 Sep 2020 19:47:31 -0700 (PDT) From: qianjun.kernel@gmail.com To: mingo@redhat.com, peterz@infradead.org, vincent.guittot@linaro.org, juri.lelli@redhat.com, linux-kernel@vger.kernel.org Cc: dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, jun qian , Yafang Shao Subject: [PATCH 1/1] sched/fair: Fix the wrong sched_stat_wait time Date: Wed, 30 Sep 2020 10:47:12 +0800 Message-Id: <20200930024712.88258-1-qianjun.kernel@gmail.com> X-Mailer: git-send-email 2.20.1 (Apple Git-117) MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: jun qian 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 (rq_of(cfs_rq)) - se->statistics.wait_start) wrong. We need to avoid this scenario. Signed-off-by: jun qian Signed-off-by: Yafang Shao --- kernel/sched/fair.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 658aa7a..dd7c3bb 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -908,6 +908,14 @@ static void update_curr_fair(struct rq *rq) if (!schedstat_enabled()) return; + /* + * 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(se->statistics.wait_start))) + return; + delta = rq_clock(rq_of(cfs_rq)) - schedstat_val(se->statistics.wait_start); if (entity_is_task(se)) { -- 1.8.3.1