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 75FFDC072A2 for ; Wed, 22 Nov 2023 06:43:25 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D892B6B0568; Wed, 22 Nov 2023 01:43:24 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id D392B6B0569; Wed, 22 Nov 2023 01:43:24 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C01516B056A; Wed, 22 Nov 2023 01:43:24 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id B0BBD6B0568 for ; Wed, 22 Nov 2023 01:43:24 -0500 (EST) Received: from smtpin23.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 77328140471 for ; Wed, 22 Nov 2023 06:43:24 +0000 (UTC) X-FDA: 81484648728.23.765F4B1 Received: from mail-lj1-f180.google.com (mail-lj1-f180.google.com [209.85.208.180]) by imf14.hostedemail.com (Postfix) with ESMTP id A0D6F100009 for ; Wed, 22 Nov 2023 06:43:22 +0000 (UTC) Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=c1tHmoqm; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf14.hostedemail.com: domain of ryncsn@gmail.com designates 209.85.208.180 as permitted sender) smtp.mailfrom=ryncsn@gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1700635402; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=/uRNxGcgpOf3kB+VZZJCqD3x4MZNwnwcErCoCSbGzaE=; b=zOTnOz9HOjpZrKG4rBsXwfR+1OvYzYVFUlc0rEf3rwTvwZ2D5gF0/c/VXgiDpvLwUSNiWa hCyir3V+LerjVzM2oT/jTyyAC/z91IvaDm5GMy3SGrKCgiD6vs+7IF955VWiNYyYu1/vQ6 caFTP0JDYWV9g9NOuTXjvY7T2m8ilnQ= ARC-Authentication-Results: i=1; imf14.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=c1tHmoqm; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf14.hostedemail.com: domain of ryncsn@gmail.com designates 209.85.208.180 as permitted sender) smtp.mailfrom=ryncsn@gmail.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1700635402; a=rsa-sha256; cv=none; b=6KUmBTxM9pBKg+x6LnfbLF0Smi3Hs5cSF0PsF3CdITqcBr4yO4tOa9N21KWhbvu2ZQiUsq cLGNM5Rzm/qm2nPYI0/yUA6+oxs6uDpkYiUbdQ19ZC/Uhr28A4sLMbFN6qUjX10CNoJeH0 FSzYOU8/kT6hB7BCi2juPnwRG8UCGwg= Received: by mail-lj1-f180.google.com with SMTP id 38308e7fff4ca-2c50906f941so85882001fa.2 for ; Tue, 21 Nov 2023 22:43:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1700635401; x=1701240201; darn=kvack.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=/uRNxGcgpOf3kB+VZZJCqD3x4MZNwnwcErCoCSbGzaE=; b=c1tHmoqmoxjzHKKdBgnhviM4oDkfh/hOGPi0bq4U4dLAjaFnqK9BmTc0YDyyMGzvBA 3j3c8zYR5NDs5jEYIv8HPqjelaOVEz/q1obau7oiFD4hD8FOpSP9jH+e4Hwtayw9a+mh aTRYnj4mzrIA9Z62lk/mAyLIMvpuYKkCH1SjA4fJBMXHnnnZPxc2yAcsc9yrhgx7shE3 IhrbuMaLY2EF7Pm2coIUEbo2nG2zEubwMK3rFQIp3XozFhUp9Tsqg9wTzWalVj809ohG WIb0KJwghiZca5x5FT0EaUQ2yZAckq+l6D1rQPr9y4pWBOu9efTU7pwWMd9qiZy+P7Xm xAfQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1700635401; x=1701240201; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=/uRNxGcgpOf3kB+VZZJCqD3x4MZNwnwcErCoCSbGzaE=; b=nNxmNxvc8nga735EGk5LdKk9cjCb1LIbwdygBOplXSGphHKN/+VeEcA0Jbl+12kdkh rjTgJ9hbURDrmy2ysOOfyyS9v5pGfKpkzUGLaLPY7ZNeAuRC73MCTmCTBnGvlvAFGFsM lDJowU7aa0zcFhAwe982GuThDJViEjsH5EsSw9vMeHUMdPDkfP0KRfXO18XUtC9VHwEo 5nunoZ9H2xLx4jRWg0g4sR9PnY7YaKutYxK0qxCWxUiEH9Y2Xt8TpWvvfSAS9/+nzEEp BmYmNpoCFEFAznfZ+lxmp4jdfOEN2LetrfIHkJmLXBeTAYtwrPjxMstMKHPja4UjO3Vr TuMg== X-Gm-Message-State: AOJu0YxH6VqXpf7bLBmjc5pDQVAWoQd9aYpKAZOdc784kIHN0SU78XZM x6i1U3jikilONp3JgcYL6LSPG0RvqfMK10G64FM= X-Google-Smtp-Source: AGHT+IGSUqKgWEL+EYO/kobnJgdaq8c8AP53UBRrYJkvO09xGuE3mMLoFP9slL9nLe+LjIgFiNa0ZRd/A7hy6P+p0Y8= X-Received: by 2002:a2e:98d5:0:b0:2c5:174b:9a53 with SMTP id s21-20020a2e98d5000000b002c5174b9a53mr842521ljj.26.1700635400512; Tue, 21 Nov 2023 22:43:20 -0800 (PST) MIME-Version: 1.0 References: <20231119194740.94101-1-ryncsn@gmail.com> In-Reply-To: From: Kairui Song Date: Wed, 22 Nov 2023 14:43:02 +0800 Message-ID: Subject: Re: [PATCH 00/24] Swapin path refactor for optimization and bugfix To: Yosry Ahmed Cc: linux-mm@kvack.org, Andrew Morton , "Huang, Ying" , David Hildenbrand , Hugh Dickins , Johannes Weiner , Matthew Wilcox , Michal Hocko , linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: A0D6F100009 X-Rspam-User: X-Rspamd-Server: rspam04 X-Stat-Signature: hgsxxoj39o9hhq7iicoyqtfn4w5sotta X-HE-Tag: 1700635402-906723 X-HE-Meta: U2FsdGVkX1+iwLlFoYsE42jr99R4bkihoh3e6ari2k0W+b8IS8dW+qTKfkX6irP6RS9wODbhQCUO78WSH0K3R4GgzSPCckeVzB9xtX+7vto+jO4B9UEFMd0xe6PBx1Z6RHn4DNgYwWSP4fg5XngOAu3lDdfMjfP8YmnIsbyd8tzAAEju4SWQZMwWvoWReZo4ZlAImEEn+jkGhS4EUqgS4Ksmrm2VqxrlO+fler6mbEjbeAsa4TsYXM9ddQgPYjjXCFD2XXcmUmterGw5QlugUpD8HZK2FRVmN8kKexE1vC1VMTGyJqoi1DvHLz+96RF1/P121liiZKI1uSqc5dTvuubvbWSiUzyFEXj/rGRhEoh+tKiT+BEqw7ujOv3wZM4zwg/ri/wD//dN1gxp7cYjunC4UNn5tbNcC3p+rItdkzXTnAaMHmutxCy3js7RSII01h4ZsTZkE2ls9Xb0HDu6E+YDC9S2E4erAT5ZxykHHWnTONtaAXqKiGXaJ7kbk4SQSNq2yArCdvSCxIRobeN/SZVgGzTonfmt+INHsVv9dKAzfGKgyzmYWfYn0Qe98Cf+Wh+OAsRdEvxSGWanpSjtKJZhffpUH/xeOXajWVVfBDc8a1Qke2NhI+Jbe1sVChkEha20j+VmajRIivXYC3aipTwAk1BWAlMFYJ1lCzAQ1BCcupdwGrGW2zNgZGjG9xDNGhfUiD75aBNXPs6uAmaxqFmozCKX9cMbjzrQW2X8aL5cJ06IwPMV0IwKLDMG6ZztorVu0UvVYX3E84tjbHJf775xl21rTk5dlpv+qLTHn6dTKlX+eGbfjZxO52qnWcKYOSJTkXEp49Mdy6HoFrOF//FnDJ++1fHAlBcBN1ar4v5njhtwz8pIgRM8FWLGvUZq8DsFEI7gwFxTsSEexyO2p31N+DAQypwuHdznpjIiGgGXea81+rwa8EaaCKjEzoKS5pHkA2aeQCyu3DoUR6o EFdAwrxC E+E37C98rFGXm8HLpQCM6l26kR25cMIeIPmPK/R6gmpWyV0nsZD6/HhEFWkhwtjIESKoo7a0VYL9oDUFrAom5ZYh3Z/laP0ZfTx79WIj/tB5othTDZ0w7LI9K9t0IPS+/fWoMNqdRIra8dm01pRNE0OWpth2wIBsNvuogGEmRibYgZsT4EoId78SUIIXWAtrr1ux07qbfwqWl1BI9SmPm3DQ9jjNv3xSsdh4O6e8os0eVz5XRKjmSj54bn3t53rB941srKvcom07hlLr8divRE07vYjuxyKfXvAuq0iLmFi73DsKiNT7e1QivJCEHGQYe+foiaQQoUc42htCMurffQdSxZ8W4hvBJW5jQ89b3P2HFs38q+ugxaqGtSBZMl2F9iMjL2ijbQ85uY19au0I03Wikrsus3bLQT8c4tpVq0cCX6eg6P0rLuegqvDqzvWVotV/5MwNAIklV1zU= 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: List-Subscribe: List-Unsubscribe: Yosry Ahmed =E4=BA=8E2023=E5=B9=B411=E6=9C=8821=E6= =97=A5=E5=91=A8=E4=BA=8C 03:18=E5=86=99=E9=81=93=EF=BC=9A > > On Sun, Nov 19, 2023 at 11:48=E2=80=AFAM Kairui Song w= rote: > > > > From: Kairui Song > > > > This series tries to unify and clean up the swapin path, fixing a few > > issues with optimizations: > > > > 1. Memcg leak issue: when a process that previously swapped out some > > migrated to another cgroup, and the origianl cgroup is dead. If we > > do a swapoff, swapped in pages will be accounted into the process > > doing swapoff instead of the new cgroup. This will allow the process > > to use more memory than expect easily. > > > > This can be easily reproduced by: > > - Setup a swap. > > - Create memory cgroup A, B and C. > > - Spawn process P1 in cgroup A and make it swap out some pages. > > - Move process P1 to memory cgroup B. > > - Destroy cgroup A. > > - Do a swapoff in cgroup C > > - Swapped in pages is accounted into cgroup C. > > > > This patch will fix it make the swapped in pages accounted in cgroup= B. > > > > I guess this only works for anonymous memory and not shmem, right? Hi Yosry, Yes, this patch only changed the charge target for anon page. > > I think tying memcg charges to a process is not something we usually > do. Charging the pages to the memcg of the faulting process if the > previous owner is dead makes sense, it's essentially recharging the > memory to the new owner. Swapoff is indeed a special case, since the > faulting process is not the new owner, but an admin process or so. I > am guessing charging to the new memcg of the previous owner might make > sense in this case, but it is a change of behavior. After discuss with others I also found this is a controversial issue, will send separate series for this, I think it needs more discuss.