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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 18F83C2BA2B for ; Thu, 9 Apr 2020 15:24:22 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id CE217206F5 for ; Thu, 9 Apr 2020 15:24:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=chrisdown.name header.i=@chrisdown.name header.b="tJwqs1kh" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CE217206F5 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chrisdown.name Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 562528E000E; Thu, 9 Apr 2020 11:24:21 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 512318E0006; Thu, 9 Apr 2020 11:24:21 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 428608E000E; Thu, 9 Apr 2020 11:24:21 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0153.hostedemail.com [216.40.44.153]) by kanga.kvack.org (Postfix) with ESMTP id 36F838E0006 for ; Thu, 9 Apr 2020 11:24:21 -0400 (EDT) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id EE0D5181AEF1E for ; Thu, 9 Apr 2020 15:24:20 +0000 (UTC) X-FDA: 76688687880.17.bells73_7d396334f4331 X-HE-Tag: bells73_7d396334f4331 X-Filterd-Recvd-Size: 3731 Received: from mail-wm1-f54.google.com (mail-wm1-f54.google.com [209.85.128.54]) by imf23.hostedemail.com (Postfix) with ESMTP for ; Thu, 9 Apr 2020 15:24:20 +0000 (UTC) Received: by mail-wm1-f54.google.com with SMTP id h2so139652wmb.4 for ; Thu, 09 Apr 2020 08:24:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chrisdown.name; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=y6Uasohp5UNg9y1/Yu3p5ekTJRoqFqD2BtsV4x2pR0I=; b=tJwqs1khMdMVGEMNLiUcBFTGDIqguzpIzMsPiVfg5EgAVW+WBMfkKjP9HYUIcxsifN nsXbYQC6zM5zGRKyPS3TB+E17ssyTm5obRD54tsO2bPMp28xtlfhLAghjMBTOJqJgEcf piGAgYTIBDk1+nNYj+lZh0bX/P4UwSupgOjn4= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=y6Uasohp5UNg9y1/Yu3p5ekTJRoqFqD2BtsV4x2pR0I=; b=saW5xdhVC3hwbjMpqewPMmuwHPw2G0YNiMBWpSgnC1vI0JUqtmMt3yQnfZznsqWlg6 orl4OmQ9rlVsmjGERaiTEaz26nzJ1K7/yhactZyfD47Ed28IZCYHd4t6/vNzTvTV/ol+ vn178VDu2azuLV5/H84Lyu+D0hWTw43OThmrgphN8z0ivwn2tKDEZyVGhH09XWQLyuqo KBkivtlC3I/m6R0ZBerXRaKMIeY+Xxnoq+964dCYZfTl6Rt3udAVAozD994N+4BXrom2 jHwinO3/UMcMHLUva4Y3HEdCy0gUq3tm5TtdWw48RKQqXoWWQ/tkTB0afCb2WOZ7xyre 7rqw== X-Gm-Message-State: AGi0Pubp7+XJd7pyVlld7oCsuRRWIfqK6r8va/PUUP3BG8VeYz/eYZ+C mTLbXajpFGArIlqt06ptWsotXQ== X-Google-Smtp-Source: APiQypICmPk2Caj99JJJTjUv1vpKU4FXLVP3n8KXyG84Gx3X0Lgu9U6NVHypIsDGjQe34+jbxd0lTg== X-Received: by 2002:a1c:7308:: with SMTP id d8mr424161wmb.31.1586445859242; Thu, 09 Apr 2020 08:24:19 -0700 (PDT) Received: from localhost ([2620:10d:c092:180::1:9ebe]) by smtp.gmail.com with ESMTPSA id b85sm4281421wmb.21.2020.04.09.08.24.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Apr 2020 08:24:17 -0700 (PDT) Date: Thu, 9 Apr 2020 16:24:17 +0100 From: Chris Down To: Bruno =?iso-8859-1?Q?Pr=E9mont?= Cc: Michal Hocko , cgroups@vger.kernel.org, linux-mm@kvack.org, Johannes Weiner , Vladimir Davydov Subject: Re: Memory CG and 5.1 to 5.6 uprade slows backup Message-ID: <20200409152417.GB1040020@chrisdown.name> References: <20200409112505.2e1fc150@hemera.lan.sysophe.eu> <20200409094615.GE18386@dhcp22.suse.cz> <20200409121733.1a5ba17c@hemera.lan.sysophe.eu> <20200409103400.GF18386@dhcp22.suse.cz> <20200409170926.182354c3@hemera.lan.sysophe.eu> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Disposition: inline In-Reply-To: <20200409170926.182354c3@hemera.lan.sysophe.eu> 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: Bruno Pr=E9mont writes: >Could it be that cache is being prevented from being reclaimed by a task >in another cgroup? > >e.g. > cgroup/system/backup > first reads $files (reads each once) > cgroup/workload/bla > second&more reads $files > >Would $files remain associated to cgroup/system/backup and not >reclaimed there instead of being reassigned to cgroup/workload/bla? Yes, that's entirely possible. The first cgroup to fault in the pages is=20 charged for the memory. Other cgroups may use them, but they are not acco= unted=20 for as part of that other cgroup. They may also still be "active" as a re= sult=20 of use by another cgroup.