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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 8A622C2BA19 for ; Tue, 21 Apr 2020 09:24:06 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4C64A20857 for ; Tue, 21 Apr 2020 09:24:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4C64A20857 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id EE03F8E0006; Tue, 21 Apr 2020 05:24:05 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E8F718E0003; Tue, 21 Apr 2020 05:24:05 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DCC3C8E0006; Tue, 21 Apr 2020 05:24:05 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0198.hostedemail.com [216.40.44.198]) by kanga.kvack.org (Postfix) with ESMTP id C1BEE8E0003 for ; Tue, 21 Apr 2020 05:24:05 -0400 (EDT) Received: from smtpin01.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 75420824556B for ; Tue, 21 Apr 2020 09:24:05 +0000 (UTC) X-FDA: 76731325650.01.chess87_6849bc820d60 X-HE-Tag: chess87_6849bc820d60 X-Filterd-Recvd-Size: 2975 Received: from out4436.biz.mail.alibaba.com (out4436.biz.mail.alibaba.com [47.88.44.36]) by imf46.hostedemail.com (Postfix) with ESMTP for ; Tue, 21 Apr 2020 09:24:04 +0000 (UTC) X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R461e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01f04397;MF=alex.shi@linux.alibaba.com;NM=1;PH=DS;RN=11;SR=0;TI=SMTPD_---0TwDn81a_1587460953; Received: from IT-FVFX43SYHV2H.local(mailfrom:alex.shi@linux.alibaba.com fp:SMTPD_---0TwDn81a_1587460953) by smtp.aliyun-inc.com(127.0.0.1); Tue, 21 Apr 2020 17:22:34 +0800 Subject: Re: [PATCH 16/18] mm: memcontrol: charge swapin pages on instantiation To: Johannes Weiner , Joonsoo Kim Cc: Shakeel Butt , Hugh Dickins , Michal Hocko , "Kirill A. Shutemov" , Roman Gushchin , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com References: <20200420221126.341272-1-hannes@cmpxchg.org> <20200420221126.341272-17-hannes@cmpxchg.org> From: Alex Shi Message-ID: <6f03ed4e-f917-2ccc-26c0-c438c84d3d97@linux.alibaba.com> Date: Tue, 21 Apr 2020 17:21:26 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <20200420221126.341272-17-hannes@cmpxchg.org> Content-Type: text/plain; charset=gbk 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: =D4=DA 2020/4/21 =C9=CF=CE=E76:11, Johannes Weiner =D0=B4=B5=C0: > Right now, users that are otherwise memory controlled can easily > escape their containment and allocate significant amounts of memory > that they're not being charged for. That's because swap readahead > pages are not being charged until somebody actually faults them into > their page table. This can be exploited with MADV_WILLNEED, which > triggers arbitrary readahead allocations without charging the pages. >=20 > There are additional problems with the delayed charging of swap pages: >=20 > 1. To implement refault/workingset detection for anonymous pages, we > need to have a target LRU available at swapin time, but the LRU is > not determinable until the page has been charged. >=20 > 2. To implement per-cgroup LRU locking, we need page->mem_cgroup to be > stable when the page is isolated from the LRU; otherwise, the locks > change under us. But swapcache gets charged after it's already on > the LRU, and even if we cannot isolate it ourselves (since charging > is not exactly optional). >=20 > The previous patch ensured we always maintain cgroup ownership records > for swap pages. This patch moves the swapcache charging point from the > fault handler to swapin time to fix all of the above problems. >=20 > Signed-off-by: Johannes Weiner Reviewed-by: Alex Shi