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=-13.1 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,URIBL_BLOCKED,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 B7918C433DF for ; Thu, 6 Aug 2020 16:59:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 16AA823119 for ; Thu, 6 Aug 2020 16:59:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="UBJ+xRcZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729823AbgHFQ7y (ORCPT ); Thu, 6 Aug 2020 12:59:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41644 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728999AbgHFQkk (ORCPT ); Thu, 6 Aug 2020 12:40:40 -0400 Received: from mail-pl1-x642.google.com (mail-pl1-x642.google.com [IPv6:2607:f8b0:4864:20::642]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 21CA1C002174 for ; Thu, 6 Aug 2020 09:14:46 -0700 (PDT) Received: by mail-pl1-x642.google.com with SMTP id r4so17213173pls.2 for ; Thu, 06 Aug 2020 09:14:46 -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=E+VfmnxDV498yxI5rDUMFgAbVpKeY5DLzESFio3gnB4=; b=UBJ+xRcZblEVxSJwz/PK+6Kw1nyvUVkSJPh5W3yJfyKUV1zBsLoDfTSVMzPYi0aXAB MoIYnymHlZyzMpW2QDQGcE1yacW3lPSxo41W77F74qUi7yZyaUPg4mZaaTps4uw7arDv MHSZarQlh9DmRRObpE31wn60GWelGoIPB5AylEpEXUq4SI+QeMWpN/xCPgXX1c1h//Sp S9Ey6QXTSzW1azNC4LSOgHLG0DM60r0TB8IOANE/aQ4gxx5NyI3mz9gnPTAW/h9jxKfp 0lb+PuigzZbdX2MQNlrcwr4HG7qc6BD+BJ/i/5L79G1rwr7l4ZDWOMuBD7XJZmcLs1MT o4KA== 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=E+VfmnxDV498yxI5rDUMFgAbVpKeY5DLzESFio3gnB4=; b=SBwnrenk2TlLHmHqwQdZ9N44NQ2mS85L2DpxBwFRZB77ilnNExoP+VEYN5J0M1Z2Zv +tM2ip3ZuFA4zWqku8hsner9i/80LJKBNpqUhDSsFpNVqwpKkyCSfWJvvGzwwU9T0z5e w4RU33xki2cxtZ83xstkPxC0D4fU/LSKwSc8n/MpiDzC6tBCBRIlE4VOzntu002vdTH2 Vn6fcBiMpNxzZZw1BLmlztYeuLXS7BO+wRmRY5WQzDWySNIioB5NnDbzEj7QywLLe67U zg5qoR4RQcrNxXGyw5dxVgg/uLBeuZyioq+GldYdAibwPGOaZxiH9LRtixa+GEM5SItq A6EA== X-Gm-Message-State: AOAM5330OeXPq5ZwXtTN/XtgBhYo1U8WMQL1s1C0mN6jD1O7ef20Sfdn 9dikICr73SKkc45BxIif9oA= X-Google-Smtp-Source: ABdhPJygnoz1mAHZpteX4eA3W25LGEwX06xrCjfRfUvdj+ghvykms+CWaAws1JOdPxRlOy6x95gWgw== X-Received: by 2002:a17:90a:e551:: with SMTP id ei17mr9109006pjb.224.1596730485648; Thu, 06 Aug 2020 09:14:45 -0700 (PDT) Received: from localhost.localdomain ([112.44.78.113]) by smtp.gmail.com with ESMTPSA id x127sm9537245pfd.86.2020.08.06.09.14.39 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 06 Aug 2020 09:14:44 -0700 (PDT) From: Jiang Biao X-Google-Original-From: Jiang Biao To: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org Cc: dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, linux-kernel@vger.kernel.org, Jiang Biao Subject: [PATCH RFC v2] sched/fair: simplify the work when reweighting entity Date: Fri, 7 Aug 2020 00:14:06 +0800 Message-Id: <20200806161406.22629-1-benbjiang@tencent.com> X-Mailer: git-send-email 2.21.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jiang Biao If a se is on_rq when reweighting entity, all we need should be updating the load of cfs_rq, other dequeue/enqueue work could be redundant, such as, * nr_running--/nr_running++ Even though the following dequeue/enqueue path would never be reached * account_numa_dequeue/account_numa_enqueue * list_del/list_add from/into cfs_tasks but it could be a little confusing. Simplifying the logic could be helpful to reduce a litte overhead for hot path, and make it cleaner and more readable. Signed-off-by: Jiang Biao --- v2<-v1: - Amend the commit log. kernel/sched/fair.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 04fa8dbcfa4d..18a8fc7bd0de 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3086,7 +3086,7 @@ static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, /* commit outstanding execution time */ if (cfs_rq->curr == se) update_curr(cfs_rq); - account_entity_dequeue(cfs_rq, se); + update_load_sub(&cfs_rq->load, se->load.weight); } dequeue_load_avg(cfs_rq, se); @@ -3102,7 +3102,7 @@ static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, enqueue_load_avg(cfs_rq, se); if (se->on_rq) - account_entity_enqueue(cfs_rq, se); + update_load_add(&cfs_rq->load, se->load.weight); } -- 2.21.0