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=-9.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 6D14BC433E1 for ; Thu, 20 Aug 2020 12:51:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3A4562078B for ; Thu, 20 Aug 2020 12:51:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="NSQ0BROB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729162AbgHTMvw (ORCPT ); Thu, 20 Aug 2020 08:51:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59946 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728981AbgHTMvT (ORCPT ); Thu, 20 Aug 2020 08:51:19 -0400 Received: from mail-lf1-x144.google.com (mail-lf1-x144.google.com [IPv6:2a00:1450:4864:20::144]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3ED19C061385 for ; Thu, 20 Aug 2020 05:51:19 -0700 (PDT) Received: by mail-lf1-x144.google.com with SMTP id j22so877563lfm.2 for ; Thu, 20 Aug 2020 05:51:19 -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=jbR4Pr9PsKUZJNbETq29ZnQQtrCssVvEEQi3ARZG9nQ=; b=NSQ0BROBMUCayc3T1MEpDkx4BHFB0Fa2GAnXsMWQfpc9Mxm8RXXYi5lIXrgPw4T8gp RrcHrHqBxLMy+phmJVsyJet4JVoixJY1EjWaOcUoJvARS+Kogk3jxHOvaOiTFiBv3ON2 bYGM6rcx03city4YXeyfQ/Exg15Ql39gfEj/ZVmi7IgGGQahzsKTrbDi5x4T57w0PULJ ImKs6d/eNQvxJatm0TZRsDK7swAfzws9tQp49r7cjdcJqKeVXudGfcWJKNPJE04EuSDR jrUdNU0I6aCSVwBAtlNxgXAcPQN8HKPWpaKgNeHj0JneqqX0ENOv2kTcp+zf8bHyK1UC pdbQ== 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=jbR4Pr9PsKUZJNbETq29ZnQQtrCssVvEEQi3ARZG9nQ=; b=HiLXEMQNUYFwapVkgijfkDyrywfUFrXHjhdx+xWCvpD2dsm/dN0D/sUa8NPN0TCR9I IPSFl2/WMKC2MLcLwH9g7Cv5ojbNcDJXaMG3RMMe8FD9/+YswvLeiL4n8db9Ml132LiO Wcl+Bhy+6MXtnxXXsgA8xMvMw2rG6V17CAeGSlsdclRU1gfMoeBYABcHThIAGWEkHXUM U6fYEXWD3GEngHxIe+kZD93Sp8eO0U+HGRBdXcJPp2nbMqDjIK1j9n8X/Tr/gtLX1e3k 2kQ7DnNJlynNxCoxuKIOwPkho5HJe7ULVO6sDK75nrDJ2efcDsPDanjk6hGfGBv5C5V/ kaPA== X-Gm-Message-State: AOAM531iLxxKN+NuQ0Jr4CfvtcFxXpP8bSW+VDzTPrTAwFsZ88VJu9b3 3gGATHgL/wJ1gIo5XbO4ll//wcM12O/UmJEg2K6a3g== X-Google-Smtp-Source: ABdhPJyEfF3Cf/9HBpWEcyPwTPo5dMAoeC6NBCQNEMnYl5vYAY5FrV4DpuBgxEshfquiH7b1BGXzndIiHYrezc8JbBQ= X-Received: by 2002:ac2:42cd:: with SMTP id n13mr500476lfl.190.1597927877625; Thu, 20 Aug 2020 05:51:17 -0700 (PDT) MIME-Version: 1.0 References: <20200820120025.74460-1-benbjiang@tencent.com> In-Reply-To: <20200820120025.74460-1-benbjiang@tencent.com> From: Vincent Guittot Date: Thu, 20 Aug 2020 14:51:06 +0200 Message-ID: Subject: Re: [PATCH] sched/fair: avoid vruntime compensation for SCHED_IDLE task To: Jiang Biao Cc: Ingo Molnar , Peter Zijlstra , 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 14:00, Jiang Biao wrote: > > From: Jiang Biao > > Vruntime compensation has been down in place_entity() to > boot the waking procedure for fair tasks. There is no need to s/boot/boost/ ? > do that for SCHED_IDLE task actually. > > Not compensating vruntime for SCHED_IDLE task could make > SCHED_IDLE task more harmless for normal tasks. > > Signed-off-by: Jiang Biao > --- > kernel/sched/fair.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index 1a68a0536add..adff77676a0a 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -4115,7 +4115,7 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial) > vruntime += sched_vslice(cfs_rq, se); > > /* sleeps up to a single latency don't count. */ > - if (!initial) { > + if (!initial && likely(!task_has_idle_policy(task_of(se)))) { What if se is not a task ? > unsigned long thresh = sysctl_sched_latency; > > /* > -- > 2.21.0 >