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=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 BCACAC433DF for ; Thu, 20 Aug 2020 14:10:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 976E220724 for ; Thu, 20 Aug 2020 14:10:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="TDiTpn6A" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728506AbgHTOKQ (ORCPT ); Thu, 20 Aug 2020 10:10:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43828 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729084AbgHTOJb (ORCPT ); Thu, 20 Aug 2020 10:09:31 -0400 Received: from mail-lj1-x242.google.com (mail-lj1-x242.google.com [IPv6:2a00:1450:4864:20::242]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A4F23C061385 for ; Thu, 20 Aug 2020 07:09:30 -0700 (PDT) Received: by mail-lj1-x242.google.com with SMTP id w14so2248411ljj.4 for ; Thu, 20 Aug 2020 07:09:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=2QmlrH5CiuRkmxJXZDPt36i/vip9Z2n7QUlr3nkzcfk=; b=TDiTpn6AvNVYAPAHe+WHOdpes7ZCrPGKCWgYxRBAcehaFP/IOqxo11ftGmwkrlj03N IaSctJ248Ukd4xPn78MBWwSm18dDZmgIhBuPcj2woTw4jJMKIZ2wiLsqRsA9s7ACbJ69 WYymgdJAZISKTjdBQoewYjE9nCTFg6ahn4+6jdb5O87srLm9FAYFd/euB2gVVeQ3WQRa BCptZ6t8vI3WaMp0KZeDiH+qy14I2o1XTLNGS8j7U8VH5LZSOWRhK+OQcB6rqz6dyPG+ sf65dk/z5nw0v2KAAWAnHwWMpGPj3yZaX7ZV66AJGTiB2MbPSbQlXWe8IkDyuBllti+0 A+/g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=2QmlrH5CiuRkmxJXZDPt36i/vip9Z2n7QUlr3nkzcfk=; b=MBEwNVZXpGCcm4YgEbACc/Lk84gVbuVYgsxRNI8FR7Go1qIKG2KtwIFSXex3II9ns9 DFjZxi7QUuFdIZmBJit0GcdQmsrorvFh69P/oJSpf+NXX70iYGwUanWNF4WLiFdRthOj VyarL/kXMRfQn1+93+3EDapu282CO6zkNA41FJQoYNlZf01Cow05DEVQ9YeE8wO/NKfo TY9rez+s6HoYfZsKXWOKjkDgg14RI06gwIAmriELewdlu2NAYiUh+6tCEaPCMnZTGKKt Z6x2i7q+H9kz8T8XycgD2RFZvL55G14S76gQO9TCDevBrZnkW2dcs/cfxR4g8+llLG8X BvtQ== X-Gm-Message-State: AOAM5314Au+j5aVRtGI8Reztb4pXWHGCIsVTbP8l0peu3kXXKT5PHgpT pLItpWupMug8wt8rGYHw3MwRS2tJpqCeDW8JByXyMQ== X-Google-Smtp-Source: ABdhPJz571tnLGBkD4FyDqGMVdula/BPOvEP0VwtBTQiIWOGyD16OIXKdiik3BeH69NRziD5pTJE41AkBgKTE1Gk9og= X-Received: by 2002:a2e:9990:: with SMTP id w16mr1608004lji.156.1597932568936; Thu, 20 Aug 2020 07:09:28 -0700 (PDT) MIME-Version: 1.0 References: <20200820120025.74460-1-benbjiang@tencent.com> <20200820125829.GT2674@hirez.programming.kicks-ass.net> <20200820134341.GW2674@hirez.programming.kicks-ass.net> In-Reply-To: <20200820134341.GW2674@hirez.programming.kicks-ass.net> From: Vincent Guittot Date: Thu, 20 Aug 2020 16:09:17 +0200 Message-ID: Subject: Re: [PATCH] sched/fair: avoid vruntime compensation for SCHED_IDLE task To: Peter Zijlstra Cc: Jiang Biao , Ingo Molnar , Juri Lelli , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , linux-kernel , Jiang Biao Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 20 Aug 2020 at 15:44, wrote: > > > That's been said, not compensating the vruntime for a sched_idle task > > makes sense for me. Even if that will only help for others task in the > > same cfs_rq > > Yeah, but it is worth the extra pointer chasing and branches? For that I let Jiang provides figures to show the worthful > > Then again, I suppose we started all that with the idle_h_nr_running > nonsense :/