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 2C1C9C433EF for ; Tue, 8 Mar 2022 14:49:27 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A4F928D0002; Tue, 8 Mar 2022 09:49:26 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A00258D0001; Tue, 8 Mar 2022 09:49:26 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8EE3E8D0002; Tue, 8 Mar 2022 09:49:26 -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 826628D0001 for ; Tue, 8 Mar 2022 09:49:26 -0500 (EST) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 4DE8E538 for ; Tue, 8 Mar 2022 14:49:26 +0000 (UTC) X-FDA: 79221502332.14.4E85D9B Received: from mail-wr1-f46.google.com (mail-wr1-f46.google.com [209.85.221.46]) by imf07.hostedemail.com (Postfix) with ESMTP id B05E140011 for ; Tue, 8 Mar 2022 14:49:25 +0000 (UTC) Received: by mail-wr1-f46.google.com with SMTP id u10so27312106wra.9 for ; Tue, 08 Mar 2022 06:49:25 -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:references:mime-version :content-disposition:in-reply-to; bh=okjuHAEUdSBJN9BpyMg7waMBVVCyYl/QsbGBkECx2uc=; b=R0G/xcfw7NQqUxj2IvNpSY789Bl5yMhKLBUNd1HdoOgEt22/zUrl+988zKinqZcwqz 5+FUUNYQ6iIm4jYfinE4Y4zhooKXHGnrbV/ZolvFfu0OYmqieVIe151bGSPJS3xbYMBm 0orKXPtXtkYuf2Q6L1Gxnrjf4WGoFo1VlCJt0XJS3lvb+jH6RJWjnJcC5UI+YJtS3dhV IcRcwWO96WVNde8WRuO8ZpaBbN7lASQkwlKi7vaOiCZmd9ou8HYD7a0wShQ12OrTLx+w 220BERjE0NBOKfiKL1c8oXaBRJc8u6NvPn6dw+SF2TbV4Ka/efmX4zUTZEdBiFySDQX9 MQ5A== 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:references :mime-version:content-disposition:in-reply-to; bh=okjuHAEUdSBJN9BpyMg7waMBVVCyYl/QsbGBkECx2uc=; b=19FeJ+n7sogQiDbYIWutxAZDGfpaXMvOiknukfbYaqLiXq4ewfTklBreG5pmsqQieZ jOj+coftwiksmaqK1pZAaLvxOGaA2eYIKiZIyKW6+5a5TPeIyfibcRHYU8qmpPo5N3DW 4TqYbPe/59vVaixlGpqpwPgl8YrK5AGUWweSJYXMIB3Z3HGEz/bH7MiNAHdXFyxSutaz 4PICB5ySrqX7Dq0mp8a4FfGavil/o2roP6daJA/afWPAd8BTEtNHopaU4MssvuXpmCLW 8DeTAIr2WgrCQJ6Cmx6R+iwDSverN+Z3qIWtj75vhiPabaHZYe9vm5J4zocF71d5ZogO VSDw== X-Gm-Message-State: AOAM530SL+yd26sSHT4nAfB8XBIkxKO+FYSJAYsvH1ZEYLDSBHPsyldp urjDvEy0y8/wiXsSck7gnFQ= X-Google-Smtp-Source: ABdhPJx/4pBVZm9bMcaTycU1vFIALeO/IZi2aPYk064yjVQymoXXxS03yBlGX5x0bdTKQq8w72fglg== X-Received: by 2002:adf:c792:0:b0:1f0:769:9ef3 with SMTP id l18-20020adfc792000000b001f007699ef3mr12066392wrg.336.1646750964507; Tue, 08 Mar 2022 06:49:24 -0800 (PST) Received: from dschatzberg-fedora-PC0Y6AEN.fios-router.home ([2620:10d:c092:400::4:5489]) by smtp.gmail.com with ESMTPSA id y4-20020adff144000000b001f022290737sm13833388wro.6.2022.03.08.06.49.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 08 Mar 2022 06:49:24 -0800 (PST) Date: Tue, 8 Mar 2022 09:49:20 -0500 From: Dan Schatzberg To: Johannes Weiner Cc: David Rientjes , Andrew Morton , Michal Hocko , Yu Zhao , Dave Hansen , linux-mm@kvack.org, Yosry Ahmed , Wei Xu , Shakeel Butt , Greg Thelen Subject: Re: [RFC] Mechanism to induce memory reclaim Message-ID: References: <5df21376-7dd1-bf81-8414-32a73cea45dd@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: B05E140011 X-Stat-Signature: yzeqgrgiy1i5mbjp363sdems696m88fk Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b="R0G/xcfw"; spf=pass (imf07.hostedemail.com: domain of schatzberg.dan@gmail.com designates 209.85.221.46 as permitted sender) smtp.mailfrom=schatzberg.dan@gmail.com; dmarc=pass (policy=none) header.from=gmail.com X-HE-Tag: 1646750965-608471 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 Mon, Mar 07, 2022 at 03:50:36PM -0500, Johannes Weiner wrote: > On Sun, Mar 06, 2022 at 03:11:23PM -0800, David Rientjes wrote: > > - swappiness factor > > This I'm not sure about. > > Mostly because I'm not sure about swappiness in general. It balances > between anon and file, but both of them are aged according to the same > LRU rules. The only reason to prefer one over the other seems to be > when the cost of reloading one (refault vs swapin) isn't the same as > the other. That's usually a hardware property, which in a perfect > world we'd auto-tune inside the kernel based on observed IO > performance. Not sure why you'd want this per reclaim request. I think this could be useful for budgeting write-endurance. You may want to tune down a workload's swappiness on a per-reclaim basis in order to control how much swap-out (and therefore disk writes) its doing. Right now the only way to control this is by writing to vm.swappiness before doing the explicit reclaim which can momentarily effect other reclaim behavior on the machine.