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=-4.4 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,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 3F129C43381 for ; Thu, 11 Feb 2021 15:23:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0255A64EC5 for ; Thu, 11 Feb 2021 15:23:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229867AbhBKPXW (ORCPT ); Thu, 11 Feb 2021 10:23:22 -0500 Received: from m12-13.163.com ([220.181.12.13]:48941 "EHLO m12-13.163.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230363AbhBKO5H (ORCPT ); Thu, 11 Feb 2021 09:57:07 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=Subject:From:Message-ID:Date:MIME-Version; bh=Q/+NP hN+99lUgbabLKtXpk35WqE8GnVeyhv0MG+hTYY=; b=W3b4NGNPzNlQV2ms/tD3v jjCEhE8qDKNEEMUbAvL0QfgGOvgQIUh9D8v/EWhDXhxgee7w72zNdLOwLHrcntDK kNspimnZtNlCq49QIiwXxhIHUJMIGoDU7tmAsnfJnPwvQ4+68KtBYBCEqy0NvHIu eNdIxdJ6tZJD1nSMwK2hYQ= Received: from [192.168.31.184] (unknown [61.152.197.77]) by smtp9 (Coremail) with SMTP id DcCowACH5o5uDiVgMq9qew--.26070S2; Thu, 11 Feb 2021 19:01:03 +0800 (CST) Subject: Re: [PATCH] kswapd: no need reclaim cma pages triggered by unmovable allocation To: Michal Hocko Cc: iamjoonsoo.kim@lge.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, rostedt@goodmis.org, mingo@redhat.com, vbabka@suse.cz, rientjes@google.com, willy@linux.intel.com, pankaj.gupta.linux@gmail.com, bhe@redhat.com, ying.huang@intel.com, minchan@kernel.org, ruxian.feng@transsion.com, kai.cheng@transsion.com, zhao.xu@transsion.com, yunfeng.lan@transsion.com, zhouxianrong@tom.com, zhou xianrong References: <20210209082313.21969-1-xianrong_zhou@163.com> From: zhou xianrong Message-ID: Date: Thu, 11 Feb 2021 19:01:02 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-CM-TRANSID: DcCowACH5o5uDiVgMq9qew--.26070S2 X-Coremail-Antispam: 1Uf129KBjvJXoW7KryfJF4rKrykGryfGr1kGrg_yoW8JFyxpF Z3W3WUKa1kJFW5JrnFvw1FgFyIkw48Kry3J3WUurnIv3sxCrya9395Cr1j9FyFyr1UAF1Y vrWjga47Xr1kZ3DanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07jNUUbUUUUU= X-Originating-IP: [61.152.197.77] X-CM-SenderInfo: h0ld02prqjs6xkrxqiywtou0bp/xtbBUQ82z1aD95lSwQAAsP Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021/2/10 下午9:14, Michal Hocko wrote: > On Wed 10-02-21 12:07:57, zhou xianrong wrote: >> On 2021/2/9 下午5:23, Michal Hocko wrote: >>> On Tue 09-02-21 16:23:13, zhou wrote: >>>> From: zhou xianrong >>>> >>>> For purpose of better migration cma pages are allocated after >>>> failure movalbe allocations and are used normally for file pages >>>> or anonymous pages. >>>> >>>> In reclaim path so many cma pages if configurated are reclaimed >>>> from lru lists in kswapd mainly or direct reclaim triggered by >>>> unmovable or reclaimable allocations. But these cma pages can not >>>> be used by original unmovable or reclaimable allocations. So the >>>> reclaim are unnecessary. >>>> >>>> In a same system if the cma pages were configurated to large then >>>> more failture unmovable (vmalloc etc.) or reclaimable (slab etc.) >>>> allocations are arised and then more kswapd rounds are triggered >>>> and then more cma pages are reclaimed. >>> Could you be more specific? Do you have any numbers and an example >>> configuration when this is visible? >> It should be implicit. > Right but the scale of the problem is an important part of _any_ patch > justification. Sorry. The relative description is  not suitable and should be removed.