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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B6230C433EF for ; Thu, 7 Apr 2022 03:24:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238744AbiDGD0n (ORCPT ); Wed, 6 Apr 2022 23:26:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44778 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229601AbiDGD0i (ORCPT ); Wed, 6 Apr 2022 23:26:38 -0400 Received: from mail-vs1-xe32.google.com (mail-vs1-xe32.google.com [IPv6:2607:f8b0:4864:20::e32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6AC5733E0C for ; Wed, 6 Apr 2022 20:24:39 -0700 (PDT) Received: by mail-vs1-xe32.google.com with SMTP id r1so2427756vsi.12 for ; Wed, 06 Apr 2022 20:24:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=VXDoG2g2jwih4Ta9g6SsrLn0dnPRuy1eOEj+ZKrL1z0=; b=Z4BeYKfpWPYRzcHAxen+yREF0lc1qo4VdR5KzsT0cfZjxxnF1Z29F5RCDuxxSTp5uQ 3RyRHjpSt4YcVLD6TTcb7BEFmkw/QbX2ZMf489+9mEySejhjZGdwbnGGgplOd1jwH+fd wIp7/NnZ9iyfV5j9Mq+A9ogFhxQT2hNGFnmDCuJTTATa2JWvEosbVebQDLu/9M3mH2XW EfBL5zM1kvN0s/DNhKM51dS5e80jIrpf1M9D+zYru8BHaXbVc8fxuZLQSXaTtT8ag9FT omstZc/WVRk+I7i/H6VlTT7Kx7M5pC8YnQF+pdTgN4k7RfHsB1J9gKWIlL2GkN+9o5wL mgug== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=VXDoG2g2jwih4Ta9g6SsrLn0dnPRuy1eOEj+ZKrL1z0=; b=L5pHm6emfiwHH7qaj7ORAzk67BQq9hJsKJdRbwa2o0/Trub/A90bZGtR27UsAW7/je qPxgXh7qx+wIh0dwdbsmfmMphqAzDVM1RdED7MCcYeqwPwekjISOZltMfXBGmoRrF+Lo daqoQFfMZz81gLAVZK0qt3mszJg3UgEaPY2SSKfJYbc4mzT3eL8qufIniHS9xfnZw2/a qcyomYn/d2F/BAkMGe0fnC2V/suTAzyfUAvMNACbmyvVje9z19DtzTiDR4MbBm7ZcHgo qjQ7qC1MSWtg9b0gT7/3fXA1j3gr7uJBMDqbT+idLk6KeQtf8YiLL9VBf8AuBALg3yDk YfTQ== X-Gm-Message-State: AOAM530ThEZz0npip5ULPSLShH6Jcp5fZ28KCW+hl2d5YJNENQRdEjJV T/T558ioVcRxdS79y6p/HQoKziobqj3ly0pcgDhxpg== X-Google-Smtp-Source: ABdhPJwrQQIytIzXL/+SDkqLEJGG+5KzqTudCk9LM36GaMAN5lfZyghvmm3JxJvTyb4WWqBgS87nhXIBfGcmOQSDBs8= X-Received: by 2002:a05:6102:5cc:b0:320:9bd2:3823 with SMTP id v12-20020a05610205cc00b003209bd23823mr3900955vsf.81.1649301878415; Wed, 06 Apr 2022 20:24:38 -0700 (PDT) MIME-Version: 1.0 References: <20220407031525.2368067-1-yuzhao@google.com> In-Reply-To: <20220407031525.2368067-1-yuzhao@google.com> From: Yu Zhao Date: Wed, 6 Apr 2022 21:24:27 -0600 Message-ID: Subject: Re: [PATCH v10 00/14] Multi-Gen LRU Framework To: Stephen Rothwell , Linux-MM Cc: Andi Kleen , Andrew Morton , Aneesh Kumar , Barry Song <21cnbao@gmail.com>, Catalin Marinas , Dave Hansen , Hillf Danton , Jens Axboe , Jesse Barnes , Johannes Weiner , Jonathan Corbet , Linus Torvalds , Matthew Wilcox , Mel Gorman , Michael Larabel , Michal Hocko , Mike Rapoport , Rik van Riel , Vlastimil Babka , Will Deacon , Ying Huang , Linux ARM , "open list:DOCUMENTATION" , linux-kernel , Kernel Page Reclaim v2 , "the arch/x86 maintainers" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 6, 2022 at 9:15 PM Yu Zhao wrote: > > TLDR > ==== > The current page reclaim is too expensive in terms of CPU usage and it > often makes poor choices about what to evict. This patchset offers an > alternative solution that is performant, versatile and > straightforward. > Summery > ======= > The facts are: > 1. The independent lab results and the real-world applications > indicate substantial improvements; there are no known regressions. > 2. Thrashing prevention, working set estimation and proactive reclaim > work out of the box; there are no equivalent solutions. > 3. There is a lot of new code; nobody has demonstrated smaller changes > with similar effects. > > Our options, accordingly, are: > 1. Given the amount of evidence, the reported improvements will likely > materialize for a wide range of workloads. > 2. Gauging the interest from the past discussions [22][23][24], the > new features will likely be put to use for both personal computers > and data centers. > 3. Based on Google's track record, the new code will likely be well > maintained in the long term. It'd be more difficult if not > impossible to achieve similar effects on top of the current > active/inactive LRU. Hi Stephen, Can you please include this patchset in linux-next? Git repo for you to fetch: https://linux-mm.googlesource.com/mglru for-linux-next My goal is to get additional test coverage before I send a pull request for 5.19 to Linus. I've explored all avenues, but ultimately I've failed to rally substantial support from the MM stakeholders [1]. There are no pending technical issues against this patchset [2]. What is more concerning are the fundamental disagreements on priorities, methodologies, etc. that are not specific to this patchset and have been hindering our progress as a collective. (Cheers to the mutual dissatisfaction.) While we plan to discuss those issues during the LSFMM next month, it doesn't seem reasonable to leave this patchset hanging in the air, since it has reached its maturity a while ago and there are strong demands from downstream kernels as well as a large user base. Thus I sent that pull request to Linus a couple of weeks ago, implying that he would have to make the final decision soon. I hope this gives enough background about what's been going on with this patchset. If you decide to take it and it causes you any troubles, please feel free to yell at me. Thanks! [1] https://lore.kernel.org/r/20220104202227.2903605-1-yuzhao@google.com/ [2] https://lore.kernel.org/r/20220326010003.3155137-1-yuzhao@google.com/ 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4673AC433EF for ; Thu, 7 Apr 2022 04:07:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Cc:To:Subject:Message-ID:Date:From: In-Reply-To:References:MIME-Version:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=RkEA7qUR3iShskhpvKBj1op6F4PlKuoLlTBSyBgj+IM=; b=bQJJAcW6s9tsFy OUHPmaRbpoEq69bF1llQj1dwtymnIeAkyM/GaInRvEGgIYC79csugBNUu7POGM4z0iN478SihtXtQ aJi1AT0HYyJ8Sx+AyaXDtm4JI2z7xgrRTqkcEjOU0cmle8p9lehpVSSPXQgp/V5lRsZQyieYV0h5r euEkL0Ck2bNgJ2wYWHauUsxgWBlvV8dO6rD4bSqNx8MlXpzG/yPETWnD0L7ExDO+9zW/NtPbozkMZ NvBHnMnkz8tc5upkuyAH4rtDHI2gEgIT8eZfxJBZS9QKr81dwG72xhmUwS/SlwUWd4phcYQq0gx25 LDErsjSdy0/kzXkZz03w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1ncJOq-009FmH-HC; Thu, 07 Apr 2022 04:05:38 +0000 Received: from mail-vs1-xe31.google.com ([2607:f8b0:4864:20::e31]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1ncIlD-0094ri-Mr for linux-arm-kernel@lists.infradead.org; Thu, 07 Apr 2022 03:24:41 +0000 Received: by mail-vs1-xe31.google.com with SMTP id z134so2435049vsz.8 for ; Wed, 06 Apr 2022 20:24:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=VXDoG2g2jwih4Ta9g6SsrLn0dnPRuy1eOEj+ZKrL1z0=; b=Z4BeYKfpWPYRzcHAxen+yREF0lc1qo4VdR5KzsT0cfZjxxnF1Z29F5RCDuxxSTp5uQ 3RyRHjpSt4YcVLD6TTcb7BEFmkw/QbX2ZMf489+9mEySejhjZGdwbnGGgplOd1jwH+fd wIp7/NnZ9iyfV5j9Mq+A9ogFhxQT2hNGFnmDCuJTTATa2JWvEosbVebQDLu/9M3mH2XW EfBL5zM1kvN0s/DNhKM51dS5e80jIrpf1M9D+zYru8BHaXbVc8fxuZLQSXaTtT8ag9FT omstZc/WVRk+I7i/H6VlTT7Kx7M5pC8YnQF+pdTgN4k7RfHsB1J9gKWIlL2GkN+9o5wL mgug== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=VXDoG2g2jwih4Ta9g6SsrLn0dnPRuy1eOEj+ZKrL1z0=; b=b61QWEsK+WNHks2BaO40ZqUrSFNIpWGnLWDmiTMUI9TIf6bjUky8agKtwip1E9cY/3 bOSLzTsMYluuMaVbZ1lgtRuUTRSVF44gAMta+3CUK1QAuZXu/kUvH6eyu9H9uBkcHBo7 aoWjAwjNZ9tR7U8ut/BbLJBywqpRxstA0uwdb0JnIrEpknbsHtroMBlpEymXfgOPt56+ KcsdMTwL/8dtTDQX8Z+nPK8OvWuQXSQPM87agq4Y+iq3vzkxRod8eCRYTea5oVNL+0S/ bO13z4dUgMXdnXtAiBziIwv4CQdug4KMsWdMVW9o9zgFqtg4521GGXMAbuldZJJ7NK0X EbAw== X-Gm-Message-State: AOAM531yYLYZOAnRQM06vSUfTHCZtC8E+C12Mec5CrdkT2s0uj8jSa5B 63qasHDhQ4eiDk9vz89GMnBQl0qIWLCUrz/5cGUj5w== X-Google-Smtp-Source: ABdhPJwrQQIytIzXL/+SDkqLEJGG+5KzqTudCk9LM36GaMAN5lfZyghvmm3JxJvTyb4WWqBgS87nhXIBfGcmOQSDBs8= X-Received: by 2002:a05:6102:5cc:b0:320:9bd2:3823 with SMTP id v12-20020a05610205cc00b003209bd23823mr3900955vsf.81.1649301878415; Wed, 06 Apr 2022 20:24:38 -0700 (PDT) MIME-Version: 1.0 References: <20220407031525.2368067-1-yuzhao@google.com> In-Reply-To: <20220407031525.2368067-1-yuzhao@google.com> From: Yu Zhao Date: Wed, 6 Apr 2022 21:24:27 -0600 Message-ID: Subject: Re: [PATCH v10 00/14] Multi-Gen LRU Framework To: Stephen Rothwell , Linux-MM Cc: Andi Kleen , Andrew Morton , Aneesh Kumar , Barry Song <21cnbao@gmail.com>, Catalin Marinas , Dave Hansen , Hillf Danton , Jens Axboe , Jesse Barnes , Johannes Weiner , Jonathan Corbet , Linus Torvalds , Matthew Wilcox , Mel Gorman , Michael Larabel , Michal Hocko , Mike Rapoport , Rik van Riel , Vlastimil Babka , Will Deacon , Ying Huang , Linux ARM , "open list:DOCUMENTATION" , linux-kernel , Kernel Page Reclaim v2 , "the arch/x86 maintainers" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220406_202439_805563_19A78182 X-CRM114-Status: GOOD ( 22.06 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Apr 6, 2022 at 9:15 PM Yu Zhao wrote: > > TLDR > ==== > The current page reclaim is too expensive in terms of CPU usage and it > often makes poor choices about what to evict. This patchset offers an > alternative solution that is performant, versatile and > straightforward. > Summery > ======= > The facts are: > 1. The independent lab results and the real-world applications > indicate substantial improvements; there are no known regressions. > 2. Thrashing prevention, working set estimation and proactive reclaim > work out of the box; there are no equivalent solutions. > 3. There is a lot of new code; nobody has demonstrated smaller changes > with similar effects. > > Our options, accordingly, are: > 1. Given the amount of evidence, the reported improvements will likely > materialize for a wide range of workloads. > 2. Gauging the interest from the past discussions [22][23][24], the > new features will likely be put to use for both personal computers > and data centers. > 3. Based on Google's track record, the new code will likely be well > maintained in the long term. It'd be more difficult if not > impossible to achieve similar effects on top of the current > active/inactive LRU. Hi Stephen, Can you please include this patchset in linux-next? Git repo for you to fetch: https://linux-mm.googlesource.com/mglru for-linux-next My goal is to get additional test coverage before I send a pull request for 5.19 to Linus. I've explored all avenues, but ultimately I've failed to rally substantial support from the MM stakeholders [1]. There are no pending technical issues against this patchset [2]. What is more concerning are the fundamental disagreements on priorities, methodologies, etc. that are not specific to this patchset and have been hindering our progress as a collective. (Cheers to the mutual dissatisfaction.) While we plan to discuss those issues during the LSFMM next month, it doesn't seem reasonable to leave this patchset hanging in the air, since it has reached its maturity a while ago and there are strong demands from downstream kernels as well as a large user base. Thus I sent that pull request to Linus a couple of weeks ago, implying that he would have to make the final decision soon. I hope this gives enough background about what's been going on with this patchset. If you decide to take it and it causes you any troubles, please feel free to yell at me. Thanks! [1] https://lore.kernel.org/r/20220104202227.2903605-1-yuzhao@google.com/ [2] https://lore.kernel.org/r/20220326010003.3155137-1-yuzhao@google.com/ _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel