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=-5.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 0E9ADC433DB for ; Tue, 23 Feb 2021 12:30:21 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 8248C64DDC for ; Tue, 23 Feb 2021 12:30:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8248C64DDC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id B7CB56B0005; Tue, 23 Feb 2021 07:30:19 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id B54D36B0006; Tue, 23 Feb 2021 07:30:19 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A6AB16B006E; Tue, 23 Feb 2021 07:30:19 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0019.hostedemail.com [216.40.44.19]) by kanga.kvack.org (Postfix) with ESMTP id 9128C6B0005 for ; Tue, 23 Feb 2021 07:30:19 -0500 (EST) Received: from smtpin11.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 4173C180AE7E2 for ; Tue, 23 Feb 2021 12:30:19 +0000 (UTC) X-FDA: 77849465358.11.A180597 Received: from m42-2.mailgun.net (m42-2.mailgun.net [69.72.42.2]) by imf22.hostedemail.com (Postfix) with ESMTP id 43694C000C7E for ; Tue, 23 Feb 2021 12:30:13 +0000 (UTC) DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1614083418; h=Content-Transfer-Encoding: Content-Type: In-Reply-To: MIME-Version: Date: Message-ID: From: References: Cc: To: Subject: Sender; bh=RCyGcMrLAoXPkwdjDqoRBfFHog9HDnSKHwrh4kSkF7w=; b=rUGfnKK0uytbrgbRpsEiGUhe/nlDwwIvy6ipWO5kzF0DNGWNmVd89UPrOXHQF+tpTO/xm2HL L2GKfs+YQDqdl9W7cr8j8JaYZZmxx66/i9v4kpwcmxmMEaRj2y7f1OlNVbzrqk/HSaTsZpbu 7FY+aw0oAYaP0pGennF5buwBHPE= X-Mailgun-Sending-Ip: 69.72.42.2 X-Mailgun-Sid: WyIwY2Q3OCIsICJsaW51eC1tbUBrdmFjay5vcmciLCAiYmU5ZTRhIl0= Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n02.prod.us-east-1.postgun.com with SMTP id 6034f54fe87943df30eb0d41 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Tue, 23 Feb 2021 12:30:07 GMT Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 00760C433ED; Tue, 23 Feb 2021 12:30:06 +0000 (UTC) Received: from [192.168.29.110] (unknown [49.37.158.44]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: charante) by smtp.codeaurora.org (Postfix) with ESMTPSA id 756DCC433C6; Tue, 23 Feb 2021 12:30:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 756DCC433C6 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=fail smtp.mailfrom=charante@codeaurora.org Subject: Re: [PATCH RFC 0/1] mm: balancing the node zones occupancy To: David Hildenbrand , akpm@linux-foundation.org, rientjes@google.com, vbabka@suse.cz, mhocko@suse.com, mgorman@techsingularity.net, linux-mm@kvack.org Cc: vinmenon@codeaurora.org, sudaraja@codeaurora.org, linux-kernel@vger.kernel.org References: <82e0e9c2-8187-8e2f-0d5e-304dafcda017@redhat.com> From: Charan Teja Kalla Message-ID: Date: Tue, 23 Feb 2021 18:00:01 +0530 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.7.1 MIME-Version: 1.0 In-Reply-To: <82e0e9c2-8187-8e2f-0d5e-304dafcda017@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US X-Stat-Signature: ogf4yo1s6eogo9875e5jge87shy4ncbb X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 43694C000C7E Received-SPF: none (mg.codeaurora.org>: No applicable sender policy available) receiver=imf22; identity=mailfrom; envelope-from=""; helo=m42-2.mailgun.net; client-ip=69.72.42.2 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1614083413-628529 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Thanks David for the review comments!! On 2/18/2021 11:46 PM, David Hildenbrand wrote: >> I would like to start discussion about=C2=A0 balancing the occupancy o= f >> memory zones in a node in the system whose imabalance may be caused by >> migration of pages to other zones during hotremove and then hotadding >> same memory. In this case there is a lot of free memory in newly hotad= d >> memory which can be filled up by the previous migrated pages(as part o= f >> offline/hotremove) thus may free up some pressure in other zones of th= e >> node. >=20 > Why is this specific to memory hot(un)plug? I think the problem is more > generic: >=20 > Assume >=20 > 1. Application 1 allocates a lot of memory and gets ZONE_MOVABLE. > 2. Application 2 allocates a lot of memory and gets ZONE_NORMAL. > 3. Application 1 quits. >=20 > Same problem, no? Thanks for simplifying this problem. Yeah, this looks more generic problem. But for these type of problems, user/system administrator has clear view about the state of the system and thus may need to take some decisions to maintain the the node zones balancing e.g. like this change where migrate the eligible pages to other zones. --=20 The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project