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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 D7E95CA9EBB for ; Thu, 24 Oct 2019 11:11:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ADA3820684 for ; Thu, 24 Oct 2019 11:11:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lca.pw header.i=@lca.pw header.b="XZ9wsRP/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2408022AbfJXLLz (ORCPT ); Thu, 24 Oct 2019 07:11:55 -0400 Received: from mail-qt1-f193.google.com ([209.85.160.193]:43061 "EHLO mail-qt1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405717AbfJXLLy (ORCPT ); Thu, 24 Oct 2019 07:11:54 -0400 Received: by mail-qt1-f193.google.com with SMTP id t20so37215585qtr.10 for ; Thu, 24 Oct 2019 04:11:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=lca.pw; s=google; h=content-transfer-encoding:from:mime-version:subject:date:message-id :references:cc:in-reply-to:to; bh=H1HIMvQo084DWDOeY/DGgNuXCfSIuehJ6e/cH8aaOG8=; b=XZ9wsRP/Dl6l54rJvN8yPLeGOEt11uClg9G8Z0iKoz6QWoGVBSu80PdjKncPdbPj/y 2yxif1tG1j76a5xxi9/ystVvHRYzKGS9KpJyBdFMqQzPJFG/ynai7YP1K8bFMUBw/e8C irxxug7zGAo8pi9yBevnun3bcCikXaTWoB85np9sZwUyUNnvu/b+DeddVGK0NgmbrjPa PBReT2xpph3CsJTKiFxqPPYYW1QftuxbkSHiIGq5JHqwtbcLHCNg3D9cnO+enDUEFeND QffNVfJvi7e9T+VWNSx4aMubmaq+vsMZL7R947sDVVJrWoxUZ/7TgDyhYl2KgmxCGu5/ xwTw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:content-transfer-encoding:from:mime-version :subject:date:message-id:references:cc:in-reply-to:to; bh=H1HIMvQo084DWDOeY/DGgNuXCfSIuehJ6e/cH8aaOG8=; b=n3VxFa9gVC2EzBuQkntkXmZIRaLoXXCOPSTkvubSCdOB9w9T9VfdgvswEaueq7kFXb ZGjZjo4afvkc264JGZm56hgSoGPCoqA1xlAylR5byhTlrMsK+Ltd5aVmky7NSx+Og/Be yhduZTPI8ahB4OBc2SB3p+Qf8Uvlax/9T3WonJkBTwMFMqYD3qHwbgFplhzL2IslvvS9 V9hnscZaizCSG00BTnbEkeJHUF84Rf20h9eue684oJCGQTF07ydcG5j3b/g0XSb9Dgng vMmhk7hASr1iefZ3PI1ERgBvQHYcuReYsda+b0K4LOA/2e1PTPMyDKnaWGsAZPDm+1xo zqmA== X-Gm-Message-State: APjAAAXgydf2Zhz06MxmqF2MfZ+LKSad7rkHJQa/xmNi/pD3GI+G/90P vmD7yVhXND+wtMIrvd/3IuWJwQ== X-Google-Smtp-Source: APXvYqx1iWO9FW2xJmIoqvQkfPCsPC02I6Y7manmJCmQaxBy/7+dt2O23rxk0UpI6ciMzisK/xS+Dw== X-Received: by 2002:ac8:72d4:: with SMTP id o20mr3439086qtp.366.1571915513799; Thu, 24 Oct 2019 04:11:53 -0700 (PDT) Received: from [192.168.1.183] (pool-71-184-117-43.bstnma.fios.verizon.net. [71.184.117.43]) by smtp.gmail.com with ESMTPSA id d23sm13393985qkc.127.2019.10.24.04.11.53 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 24 Oct 2019 04:11:53 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable From: Qian Cai Mime-Version: 1.0 (1.0) Subject: Re: [PATCH] mm/vmstat: Reduce zone lock hold time when reading /proc/pagetypeinfo Date: Thu, 24 Oct 2019 07:11:52 -0400 Message-Id: References: <20191024074205.GQ17610@dhcp22.suse.cz> Cc: Andrew Morton , Waiman Long , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Johannes Weiner , Roman Gushchin , Vlastimil Babka , Konstantin Khlebnikov , Jann Horn , Song Liu , Greg Kroah-Hartman , Rafael Aquini In-Reply-To: <20191024074205.GQ17610@dhcp22.suse.cz> To: Michal Hocko X-Mailer: iPhone Mail (17A878) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On Oct 24, 2019, at 3:42 AM, Michal Hocko wrote: >=20 > It's been useful for debugging memory fragmentation problems and we do > not have anything that would provide a similar information. Considering Actually, zoneinfo and buddyinfo are somewhat similar to it. Why the extra i= nformation in pagetypeinfo is still useful in debugging today=E2=80=99s real= -world scenarios? > that making it root only is trivial and reducing the lock hold times > likewise I do not really see any strong reason to dump it at this > moment. There is no need to hurry this, and clearly this is rather a good opportunit= y to discuss the consolidation of memory fragmentation debugging to ease the= maintenance in long term.=