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 9CAF9C2D0E4 for ; Tue, 17 Nov 2020 14:31:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 32D6A2222E for ; Tue, 17 Nov 2020 14:31:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="Y+j3kYy6" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728856AbgKQObg (ORCPT ); Tue, 17 Nov 2020 09:31:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42066 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727473AbgKQObe (ORCPT ); Tue, 17 Nov 2020 09:31:34 -0500 Received: from mail-lj1-x243.google.com (mail-lj1-x243.google.com [IPv6:2a00:1450:4864:20::243]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 15ADDC0613CF for ; Tue, 17 Nov 2020 06:31:33 -0800 (PST) Received: by mail-lj1-x243.google.com with SMTP id 142so10845086ljj.10 for ; Tue, 17 Nov 2020 06:31:32 -0800 (PST) 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=CRNNMopfkxn+VbJFF8fI8tGBFKP5orloO2rQjUFQKOI=; b=Y+j3kYy6CxUVpJjX7uiv8z7kUFQHFfUnW9E0aI+eOYbtbt9nS2SMFoEUKTnwpvBUu+ 0lQJ5/liKye2i5rZW8uFJRRyeBQdr4DuPKQCkmGL5ubzxFm+FgmZw0irLfRPvi1egPLq K7rVTVLzIv6K4M4L09dGY2RvA+GzzJyUPH+mFdPC013corbwI8z8WW4mn/UrK5oKw5gr LluD3kJed8bGNncliPXXXwWLcNRJ10BhgJryKOjPNVN2WlKvQI5C2U8xbjZCHi/yR/ZI E2+u3W2f/DAZD4LPtLkl0hkebQXMIplJD52nG+lA8FsslNMvewcGYddshfKBsh6NSY52 A77w== 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=CRNNMopfkxn+VbJFF8fI8tGBFKP5orloO2rQjUFQKOI=; b=BE8nft6xyXS4XVPpb5wjFx4G2JtGwkQA7g2bLv94BcJM+6qAdOZFaoxmtCVAZT7yqE TGDQ2lOOxVYsaSXAVSdr6xW3A8qMtAJctGmQi4pskehVt6Q4xnVDgemG2oWgpVTn8iic Dm7Q3XSSUHbX2tEv4A8ySPyKFnfC4wvWbDvCxkt28vc7GRFzCb4lgQTI246o+tyeR0rP POuTHRSUPOU1r1msCLiNowDpnL4qQXAsZFvlC9EKUm363LVFbHt373D924ZFxO/+7z8p uVmiYY38NInSeokk2HmKJpCRq3VQiB9/pt6eKud2+xE3HHlCkE2ARdGJ+HN+OL5U/Kud QaEg== X-Gm-Message-State: AOAM530lOLDBbo9TP2pFq5w+ZaUujK/gJL4AMARkA8LWozCKuJEs3+BT 49miXzE1Iq86aT1al/OdfJDc2f7ERHi9S7AA305Xjw== X-Google-Smtp-Source: ABdhPJwhFmmmrgC7UXjA7BTEFoJsK9fNW3jfe2IY5edq9Fj8wxs51CC8G1UDkNLs8JvWkLj1TaUUNtitFeqWzOQCp6g= X-Received: by 2002:a2e:8050:: with SMTP id p16mr2174189ljg.69.1605623491013; Tue, 17 Nov 2020 06:31:31 -0800 (PST) MIME-Version: 1.0 References: <20201117134222.31482-1-mgorman@techsingularity.net> <20201117134222.31482-4-mgorman@techsingularity.net> <20201117141814.GN3121392@hirez.programming.kicks-ass.net> In-Reply-To: <20201117141814.GN3121392@hirez.programming.kicks-ass.net> From: Vincent Guittot Date: Tue, 17 Nov 2020 15:31:19 +0100 Message-ID: Subject: Re: [PATCH 3/3] sched/numa: Limit the amount of imbalance that can exist at fork time To: Peter Zijlstra Cc: Mel Gorman , LKML , Ingo Molnar , Valentin Schneider , Juri Lelli Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 17 Nov 2020 at 15:18, Peter Zijlstra wrote: > > On Tue, Nov 17, 2020 at 01:42:22PM +0000, Mel Gorman wrote: > > - if (local_sgs.idle_cpus) > > + if (local_sgs.idle_cpus >= (sd->span_weight >> 2)) > > return NULL; > > Is that the same 25% ? same question for me could we encapsulate this 25% allowed imbalance like for adjust_numa_imbalance