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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7838EC433FE for ; Thu, 10 Mar 2022 23:55:15 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id EFC0E8D0002; Thu, 10 Mar 2022 18:55:14 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id EAAA78D0001; Thu, 10 Mar 2022 18:55:14 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D72628D0002; Thu, 10 Mar 2022 18:55:14 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.25]) by kanga.kvack.org (Postfix) with ESMTP id C7D7B8D0001 for ; Thu, 10 Mar 2022 18:55:14 -0500 (EST) Received: from smtpin15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 9C07A2387D for ; Thu, 10 Mar 2022 23:55:14 +0000 (UTC) X-FDA: 79230135348.15.1C4AB52 Received: from mail-ej1-f41.google.com (mail-ej1-f41.google.com [209.85.218.41]) by imf08.hostedemail.com (Postfix) with ESMTP id 2781216001C for ; Thu, 10 Mar 2022 23:55:14 +0000 (UTC) Received: by mail-ej1-f41.google.com with SMTP id dr20so15520241ejc.6 for ; Thu, 10 Mar 2022 15:55:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:reply-to:references:mime-version :content-disposition:in-reply-to:user-agent; bh=xZ6UNijk+8fR6sxhT3uosvQMAg54vwl80TP88uESaak=; b=XM21VLJKPPRv73+hFuw4W1yLb52eqWF02QVjdDSyzl7KvtU0Rbpp6Bz84KC9pdhr+7 subfZPpcr6GULDAPlJkzxB/38Pd34zsy2PU7hxsmKEvMddHWLrxFbO5TgdsdDDvv7cFm yKuaOBOHzREJyz4podBxWUZMvSVipjhzJ11+J5014IfDz+fNuQzXAnNWGCTWYDw2/Bhv Vk7noKb8nYu2GNWZfdiwQS4bj2IZK2EcaLOqg8Vzsw580aRuXiN5xXNJl0uZ1oTOZuWJ PUv57UQYkFzLQHMw2rrqKBpiaZdAfLBoGr6TjbMCd5kCiv73ndeHtmUjZlmeM3ZEr6ig wgQw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:reply-to :references:mime-version:content-disposition:in-reply-to:user-agent; bh=xZ6UNijk+8fR6sxhT3uosvQMAg54vwl80TP88uESaak=; b=O1UIJsQHV02yEwuzZTZKRI++yzZSzxLTtLjju3DqXb9O8YhPZQdmhas/injRKMYz0o AogtKV+dH7a6pb3U1laqp9hMzjiyD5FANAxBKXWa9/G454KKE0U2OXSHFyePBWSxFV6J nCkiQdJlKgvkUEe0YYr7ViEryc+Bm8yLzwlxlnvpVagctTCjNE5GJzf3mFjK500ebz2Y 8BQhc6AGXBhYOfZL5kRwtAEtisbf3AKUHFEf34qTzxiGC/8e99BWmByEafrdm5tMj0p4 o20GALtdjVUG+xXrdz2LFYlyLV5oVNynCLiCYzJp4GyhAJn+Yu2xWlNWg0mH8aBHpGDH piUQ== X-Gm-Message-State: AOAM531c/E6tWas1wpXCmHlKMS5V4Hp6k89+uLdGl1Zao2IHIIVdZ80l mSX3bEZf4TRzTl0ma66jfBY= X-Google-Smtp-Source: ABdhPJyRkaWoZoOCievIZuzcI+SDCcwGbyfWqVJXeh41CDDL7d9Ntmmw+wHuTB8A4r1Y9Zeg/HjjnQ== X-Received: by 2002:a17:907:7f94:b0:6da:64ec:fabc with SMTP id qk20-20020a1709077f9400b006da64ecfabcmr6407150ejc.717.1646956512668; Thu, 10 Mar 2022 15:55:12 -0800 (PST) Received: from localhost ([185.92.221.13]) by smtp.gmail.com with ESMTPSA id w10-20020a17090652ca00b006c605703245sm2325074ejn.43.2022.03.10.15.55.12 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Thu, 10 Mar 2022 15:55:12 -0800 (PST) Date: Thu, 10 Mar 2022 23:55:11 +0000 From: Wei Yang To: Michal Hocko Cc: Wei Yang , hannes@cmpxchg.org, vdavydov.dev@gmail.com, akpm@linux-foundation.org, cgroups@vger.kernel.org, linux-mm@kvack.org, Tim Chen Subject: Re: [PATCH 3/3] mm/memcg: add next_mz back if not reclaimed yet Message-ID: <20220310235511.maeewfjl4k5dw576@master> Reply-To: Wei Yang References: <20220308012047.26638-1-richard.weiyang@gmail.com> <20220308012047.26638-3-richard.weiyang@gmail.com> <20220309004620.fgotfh4wsquscbfn@master> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170113 (1.7.2) Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=XM21VLJK; spf=pass (imf08.hostedemail.com: domain of richard.weiyang@gmail.com designates 209.85.218.41 as permitted sender) smtp.mailfrom=richard.weiyang@gmail.com; dmarc=pass (policy=none) header.from=gmail.com X-Rspam-User: X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 2781216001C X-Stat-Signature: yhrjwzag3ued4ae5wo9p8rnikox5w9h3 X-HE-Tag: 1646956514-565193 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: On Thu, Mar 10, 2022 at 09:59:30AM +0100, Michal Hocko wrote: >On Wed 09-03-22 14:48:46, Michal Hocko wrote: >> [Cc Tim - the patch is http://lkml.kernel.org/r/20220308012047.26638-3-richard.weiyang@gmail.com] >> >> On Wed 09-03-22 00:46:20, Wei Yang wrote: >> > On Tue, Mar 08, 2022 at 09:17:58AM +0100, Michal Hocko wrote: >> > >On Tue 08-03-22 01:20:47, Wei Yang wrote: >> > >> next_mz is removed from rb_tree, let's add it back if no reclaim has >> > >> been tried. >> > > >> > >Could you elaborate more why we need/want this? >> > > >> > >> > Per my understanding, we add back the right most node even reclaim makes no >> > progress, so it is reasonable to add back a node if we didn't get a chance to >> > do reclaim on it. >> >> Your patch sounded familiar and I can remember now. The same fix has >> been posted by Tim last year >> https://lore.kernel.org/linux-mm/8d35206601ccf0e1fe021d24405b2a0c2f4e052f.1613584277.git.tim.c.chen@linux.intel.com/ > >Btw. I forgot to mention yesterday. Whatever was the reason this has >slipped through cracks it would great if you could reuse the changelog >of the original patch which was more verbose and explicit about the >underlying problem. The only remaining part I would add is a description >of how serious the problem is. The removed memcg would be out of the >excess tree until further memory charges would get it back. But that can >take arbitrary amount of time. Whether that is a real problem would >depend on the workload of course but considering how coarse of a tool >the soft limit is it is possible that this is not something most users >would even notice. Got it, would send a v2. >-- >Michal Hocko >SUSE Labs -- Wei Yang Help you, Help me