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[23.128.96.18]) by mx.google.com with ESMTP id n26si34956362edr.231.2021.11.09.07.52.23; Tue, 09 Nov 2021 07:52:49 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@bytedance-com.20210112.gappssmtp.com header.s=20210112 header.b=H4a4IucM; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=bytedance.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241695AbhKIIb2 (ORCPT + 99 others); Tue, 9 Nov 2021 03:31:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58738 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236798AbhKIIb1 (ORCPT ); Tue, 9 Nov 2021 03:31:27 -0500 Received: from mail-ed1-x530.google.com (mail-ed1-x530.google.com [IPv6:2a00:1450:4864:20::530]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9ABEDC061767 for ; Tue, 9 Nov 2021 00:28:41 -0800 (PST) Received: by mail-ed1-x530.google.com with SMTP id ee33so73818678edb.8 for ; Tue, 09 Nov 2021 00:28:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=AYfmttMzhsd8uEz1aHBUrg2dnF3audYy8hGqqui2EpI=; b=H4a4IucMj8HDXTeG6u/Oz0ceqJbOqvSSg1DGCicM5zW8caqvUxA8hwZwgnomWSI2ju jx9JawN0XSBy/yqwpwZ9Zh81+Fuo/fUQs/OxpGJUzrdHzmFxk15hlK/0iwwrXWslsuU6 7wBOt5AIcO4LZEe0egpWgofjLRMJxj93X5VzXOjX/SpKWhk2YBS1Y6vMA/16dUGWHzun Iyl/fitIbpsVL/RWKjRNbCrsDPP65wzA3pwhqy2cyTYX/72Thm/8MkVJLN0Dm5lvdzU9 7H9byrChhb3YL7hLSKt3jIMjc6Cmj3XrWrUxwfmyhrS/jDWjCj02eHzhs0sTa0aeFfC+ SU9Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=AYfmttMzhsd8uEz1aHBUrg2dnF3audYy8hGqqui2EpI=; b=plNIWRPd40bWeOPw1hsEUTni7gZuIbzhI1t4vCM6jUHlnFijWvAJjvA3RdRPYsSInX 2nA2Cm/gV2Vf7siV0a9C4hstDut1F4FQgx5hg6bPawrd3AlosftIwTfd3bgVUktFxhcc DUgfW3b5v2J8ODlLyLYCDv0FTqz3zHoDBdOY07BmzYSeOOkplNihPy+VUbU6JLQWSzLO LC0/QH1RDz+HYwnAcQ6rgQMlWRx8dSytm+TQpWi3OPtIGNLSBKG1uL1f3yPcebGTIEIC /czE7utaBd4c9f3RPoGw9NUtJD/vV0g2r7RPDzC0aEm4cnf2M0Iwhi5LOyXVlaZJvPR5 tKfA== X-Gm-Message-State: AOAM533L1np62yZBefmyUSsskFd/091zPCfBgOqgn0olFcj78v2EQxLu fT2Wb838mcdo5LKU3MBXNdaTHz2OEM5EFAIlnYl6cEVeBWVPhg== X-Received: by 2002:a17:906:38ce:: with SMTP id r14mr7278587ejd.268.1636446520068; Tue, 09 Nov 2021 00:28:40 -0800 (PST) MIME-Version: 1.0 References: <20211027132633.86653-1-ligang.bdlg@bytedance.com> <20211028153028.GP3891@suse.de> <20211029083751.GR3891@suse.de> In-Reply-To: <20211029083751.GR3891@suse.de> From: =?UTF-8?B?5p2O5riv?= Date: Tue, 9 Nov 2021 16:28:28 +0800 Message-ID: Subject: Re: Re: Re: [PATCH v1] sched/numa: add per-process numa_balancing To: Mel Gorman Cc: Jonathan Corbet , Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Daniel Bristot de Oliveira , linux-api@vger.kernel.org, LKML , linux-fsdevel@vger.kernel.org, linux-doc@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, sorry for the late reply. On Fri, Oct 29, 2021 at 4:37 PM Mel Gorman wrote: > > My point is that as it stands, > prctl(PR_NUMA_BALANCING,PR_SET_NUMA_BALANCING,1) either does nothing or > fails. If per-process numa balancing is to be introduced, it should have > meaning with the global tuning affecting default behaviour and the prctl > affecting specific behaviour. > If the global tuning affects default behaviour and the prctl affects specific behaviour. Then when prctl specifies numa_balancing for a process, there is no way for the global tuning to affect that process. In other words, global tuning become a default value, not a switch for global numa_balancing. My idea is that the global numa_balancning still has absolute control, and prctl can only optionally turn off numa_balancing for process when the global is on. After all, It is more common to enable global numa_balancing and disable it in several processes than to disable global numa_balancing and enable it in several processes. This is my personal opinion, what do you think. :-) Do we need the global to be a switch, or a default value?