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=-17.6 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, 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,USER_IN_DEF_DKIM_WL 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 83E4CC433DF for ; Tue, 4 Aug 2020 19:24:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6510022B42 for ; Tue, 4 Aug 2020 19:24:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="pxfZMucz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728121AbgHDTY4 (ORCPT ); Tue, 4 Aug 2020 15:24:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46378 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726027AbgHDTYz (ORCPT ); Tue, 4 Aug 2020 15:24:55 -0400 Received: from mail-qk1-x744.google.com (mail-qk1-x744.google.com [IPv6:2607:f8b0:4864:20::744]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5DFAFC06174A for ; Tue, 4 Aug 2020 12:24:55 -0700 (PDT) Received: by mail-qk1-x744.google.com with SMTP id h7so39464420qkk.7 for ; Tue, 04 Aug 2020 12:24:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=pzsHuz3jz2KjqjbdXSlm4QZoLu4U8KSe5A09SXjkgoM=; b=pxfZMuczjhW/F8JFU7DtDbRoeILs3IStkDcNky/fJGelBVVhrK6RDX/i8xekFGTQLM 8aEGWH690sudIfYarn+0BOFjl6eO96prLV0OppiwlmxGDHdIenQFHdXAFK+jYYTsyg40 PuRh4BRc2RoJ5uMYVGBfIsW1RoJwmcZG3S1GNjK6uAIZUE1XXSXubWOHeNZFFHnWWNM7 REcZ5peEYawXrcYglST5UMJ82do8tM7DN8/BhW7fw1HXzqBb6u7bOGvZ7hNK4D70/hdX qu8POu2iJ04zAxE8f/TJDfjm/St+52WnUHaPeUpqhGKaTGWcMJvf35VKUVVGm9PskSal 9hew== 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=pzsHuz3jz2KjqjbdXSlm4QZoLu4U8KSe5A09SXjkgoM=; b=C7xGAlOHgEeh2veD6lv/7V83Dlg7+XYjqAfQJZF/ksU8gTocYYNsHPrPTdMcR/BJ6M uKfyLjPntcUMFUB4y5KuGlLie1Jua31rcGQLkBi6pXb13e/2SSl6AvvELR3lw9jpg1pE TOIaiMXWjzn64CnYY1otLDoFnTCc17UemFpV/7GM5HxXsWx8GArQbukAsrIV0epvM6aw vsqiHf/OelBeu2oWBiaXXumhBAxNQ4xpCB2DRhjU/ykEyqktvo/Je594tU4BTPgkHUiY ymddd5zeYVe8v1yQkjSgjNvPECweHkexkezXvNPe/EMtObrlefrIXFi3C9LUShCwSOZD 8M3w== X-Gm-Message-State: AOAM532+abmOfc4vR2y3tyMNzrbfsmruXy/FMwz/PNqtKtGV9YTEX7pe ToTCQGQ2q++QVygdzuit2wwxT6gVv/LpeHj5f5eJjQ== X-Google-Smtp-Source: ABdhPJwXWvCIO8Y8R/+lIlTuLCsmrpuS6BKzpZJHHVUHLJbb4ZaN2z9pD5qQ8Cogh5sEA6/8nK1FaweDpNFgdH55DN4= X-Received: by 2002:a05:620a:15e8:: with SMTP id p8mr22024185qkm.182.1596569094262; Tue, 04 Aug 2020 12:24:54 -0700 (PDT) MIME-Version: 1.0 References: <20200804000614.4176212-1-joshdon@google.com> <20200804105619.GE2657@hirez.programming.kicks-ass.net> In-Reply-To: <20200804105619.GE2657@hirez.programming.kicks-ass.net> From: Josh Don Date: Tue, 4 Aug 2020 12:24:43 -0700 Message-ID: Subject: Re: [PATCH] sched/fair: ignore cache hotness for SMT migration To: Peter Zijlstra Cc: Ingo Molnar , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , linux-kernel 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 Tue, Aug 4, 2020 at 3:56 AM wrote: > > On Mon, Aug 03, 2020 at 05:06:14PM -0700, Josh Don wrote: > > SMT siblings share caches, so cache hotness should be irrelevant for > > cross-sibling migration. > > > > Proposed-by: Venkatesh Pallipadi > > Signed-off-by: Josh Don > > --- > > kernel/sched/fair.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > > index 2ba8f230feb9..5b203b55bcb2 100644 > > --- a/kernel/sched/fair.c > > +++ b/kernel/sched/fair.c > > @@ -7402,6 +7402,9 @@ static int task_hot(struct task_struct *p, struct lb_env *env) > > if (unlikely(task_has_idle_policy(p))) > > return 0; > > > > + if ((env->sd->flags & cpu_smt_flags()) == cpu_smt_flags()) > > + return 0; > > I think that wants to be: > > if (env->sd->flags & SD_SHARE_CPUCAPACITY) > Agreed > Also, perhaps stick a comment on top with the rationale for this. > > > + > > /* > > * Buddy candidates are cache hot: > > */ > > -- > > 2.28.0.163.g6104cc2f0b6-goog > >