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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A97C7C433EF for ; Wed, 13 Jul 2022 04:05:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233584AbiGMEFr (ORCPT ); Wed, 13 Jul 2022 00:05:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43350 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231423AbiGMEFW (ORCPT ); Wed, 13 Jul 2022 00:05:22 -0400 Received: from mail-pg1-x533.google.com (mail-pg1-x533.google.com [IPv6:2607:f8b0:4864:20::533]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 30F78D9E1B for ; Tue, 12 Jul 2022 21:05:22 -0700 (PDT) Received: by mail-pg1-x533.google.com with SMTP id 72so9432252pge.0 for ; Tue, 12 Jul 2022 21:05:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=+2tUbyN2xCwMNnYylDuWSr4Ej/rDbj2w3froYdg0Q9I=; b=P7qQ0aXggkw+HRGyGnwGQUN4Ud+8NUR/peIiuMfu02rzQ/bNWeltmRIUSWcFMiA9A6 5j7PDwOHC4NsC59zdDPIVjsG/sbiyrLD+SqPbXHq7uBxr2UqFpJ3LNwl9z5CAkQY58bM 0YftkC6HDJ9DRddF0ppbnBuNLLM8x+6+RqFIflRtvaTGKTnKCLIYgbe2B1Kp5Oxc3nwQ yEwsFxWizmNgvkFSMSC6lt9aOSlXGYZOg04nXP7ZDn/GS6/Fau8PZpo1K1aLJ672iRgJ UZrKwO/fH1qdVsitGLCulSpRWZWiaXjVJ10BdXUDmiuM0kC1WseG2SYVho/ZM/tBDLGg 7k7w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=+2tUbyN2xCwMNnYylDuWSr4Ej/rDbj2w3froYdg0Q9I=; b=Y4kNSKxvO7/5toAZIjhAtt3QsYpws0IhDzKk7VUSOwQmcjWGlIOfOW7RfcDkci1G74 5prvutcyR0Royk6FRAwJHy6NI36Zy1JjnhYqqgFVmK6DLKmsVT3XdGHydNawEXCyU+6s FoU5XsgTomszjrsdEHYhcAj+7OCv0/mXw9PYkpP6AWWl3og2IdLYGMVKhpTieuXk0SWN ddg4iYwR8zTbj6aNGcES6MAZKTVfcDJB3ZhVWcepwKf516T8QOc/NEqZeIMggtFtVhjR Xzq7+mhZXgT+a9u799F2sIFyemLzKFyEdgOlOlFZPu9fk1lP7AGrFJh+3qtQjZ4f6fHy uqfg== X-Gm-Message-State: AJIora9eCSMuZ3kV15zI+sb6Is9G0oAI8SW9nx1G64gq8OB6VegPEei6 VCriujKPUwS+MalMOXzK1C3Ymw== X-Google-Smtp-Source: AGRyM1u6cXFHA6c24+Zt2sngu9RaumNXGT5FU4M2mMn5qYUeliCH0e7zSV4ly5ZeraCfygLbA09qqw== X-Received: by 2002:a05:6a00:a1f:b0:525:3ad6:fb7e with SMTP id p31-20020a056a000a1f00b005253ad6fb7emr1208891pfh.68.1657685121712; Tue, 12 Jul 2022 21:05:21 -0700 (PDT) Received: from localhost.localdomain ([139.177.225.235]) by smtp.gmail.com with ESMTPSA id y12-20020a17090322cc00b0016bd16f8acbsm6858942plg.114.2022.07.12.21.05.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 12 Jul 2022 21:05:21 -0700 (PDT) From: Chengming Zhou To: mingo@redhat.com, peterz@infradead.org, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, vschneid@redhat.com Cc: linux-kernel@vger.kernel.org, Chengming Zhou Subject: [PATCH v2 09/10] sched/fair: stop load tracking when task switched_from_fair() Date: Wed, 13 Jul 2022 12:04:29 +0800 Message-Id: <20220713040430.25778-10-zhouchengming@bytedance.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220713040430.25778-1-zhouchengming@bytedance.com> References: <20220713040430.25778-1-zhouchengming@bytedance.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The same reason as the previous commit, if we don't reset the sched_avg last_update_time to 0, after a while in switched_to_fair(): switched_to_fair attach_task_cfs_rq attach_entity_cfs_rq update_load_avg __update_load_avg_se(now, cfs_rq, se) The delta (now - sa->last_update_time) will wrongly contribute/decay sched_avg depends on the task running/runnable status at that time. This patch reset it's sched_avg last_update_time to 0, stop load tracking for !fair task, later in switched_to_fair() -> update_load_avg(), we can use its saved sched_avg. Signed-off-by: Chengming Zhou --- kernel/sched/fair.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 50f65a2ede32..576028f5a09e 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -11552,6 +11552,11 @@ static void attach_task_cfs_rq(struct task_struct *p) static void switched_from_fair(struct rq *rq, struct task_struct *p) { detach_task_cfs_rq(p); + +#ifdef CONFIG_SMP + /* Stop load tracking for !fair task */ + p->se.avg.last_update_time = 0; +#endif } static void switched_to_fair(struct rq *rq, struct task_struct *p) -- 2.36.1