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 9BC73C433EF for ; Sat, 16 Apr 2022 00:03:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356688AbiDPAGY (ORCPT ); Fri, 15 Apr 2022 20:06:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59176 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230458AbiDPAGX (ORCPT ); Fri, 15 Apr 2022 20:06:23 -0400 Received: from mail-vs1-xe30.google.com (mail-vs1-xe30.google.com [IPv6:2607:f8b0:4864:20::e30]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 146264338E for ; Fri, 15 Apr 2022 17:03:54 -0700 (PDT) Received: by mail-vs1-xe30.google.com with SMTP id j16so8170853vsv.2 for ; Fri, 15 Apr 2022 17:03:54 -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=ztOn9qTNjZOdib9wu9VtT2ux2AzPcxh/m+7PKVCw6iQ=; b=R5JSg0OZdet4qAUAD70eGrmGlbnfq6SE/UKMx9mVP3XjOuHnA4bSF78m1q8xItuGE9 vjqnxSxQ4spxqIw4T67UAoX/WAcpVdYRh0Do8X6bcppYXWpUgrN8T6JkIEu/GY1wQYyh A68dT7GLg+KlcZh58eo3TpGvYK6OsZzyfMZQDrLE0MQ6uR9X86jvNVceMpuK6ksQ1AGF vNgu+/XSqK9byqpg3ekX51zXiD0AKThWb3YM076hxyjIsBkx1tLG5G2nPZKahaiU1EQ/ FUnVlc5HTy63gEsQMroqaIki707KQUKD83kXincChwkr/HdyaaFWnemn3Dfdf9e2bpd8 6Bgg== 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=ztOn9qTNjZOdib9wu9VtT2ux2AzPcxh/m+7PKVCw6iQ=; b=z1/CiPZVE562ifCzJqf4LgB78KOkQ9/icosjaD98ZPRp56xe1YfV6KRF3PI2ebJ/e+ P4VIjYR7Yu32Miq0Ixo3m4H0O82JL9Hg4Tj1LifR54CxPTLXSwcD2kdTUJRAnyTrvGig BgpohrrwYlaGy9lZS0vr8f11wBv44Ir1QE971EjgDLY1gWSUVNMyREbD1SfRaN9EGfcb yfZyVx9Fsdsb9lXSDyM//V2EqxPfJWH+hPsqTxi2lbSPMfexdobY/IQylX3Y5MTU+nRe AxxmDQcenKvg7GC5egQsXQ2ovpOWUrnPiPBgOeluYT+0DAehuDD9A9km86VQbPGtyLGe OiGg== X-Gm-Message-State: AOAM53077/cdQZhX1+YcVrz7EkJPOvUlM2SE+Q56DklF3+vENQi2RKpW WOLFmZOB455+9EfV5NlCN+nqSmYOZpaLBxQPdYtZgQ== X-Google-Smtp-Source: ABdhPJw2ERJ54VhqBYtjNfKf1yIUSVFp1Wz9yRWf2I17eE6bxYiU0nBVH1Y+brrNjKX5bhrMgcp/2etChjEHOe5V/60= X-Received: by 2002:a05:6102:3753:b0:325:c20e:4b1c with SMTP id u19-20020a056102375300b00325c20e4b1cmr371331vst.84.1650067433140; Fri, 15 Apr 2022 17:03:53 -0700 (PDT) MIME-Version: 1.0 References: <20220407031525.2368067-1-yuzhao@google.com> <20220407031525.2368067-13-yuzhao@google.com> <20220411191634.674554d3de2ba37b3db40ca2@linux-foundation.org> In-Reply-To: <20220411191634.674554d3de2ba37b3db40ca2@linux-foundation.org> From: Yu Zhao Date: Fri, 15 Apr 2022 18:03:16 -0600 Message-ID: Subject: Re: [PATCH v10 12/14] mm: multi-gen LRU: debugfs interface To: Andrew Morton Cc: Stephen Rothwell , Linux-MM , Andi Kleen , 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" , Brian Geffon , Jan Alexander Steffens , Oleksandr Natalenko , Steven Barrett , Suleiman Souhlal , Daniel Byrne , Donald Carr , =?UTF-8?Q?Holger_Hoffst=C3=A4tte?= , Konstantin Kharlamov , Shuang Zhai , Sofia Trinh , Vaibhav Jain Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Mon, Apr 11, 2022 at 8:16 PM Andrew Morton wrote: > > On Wed, 6 Apr 2022 21:15:24 -0600 Yu Zhao wrote: > > > Add /sys/kernel/debug/lru_gen for working set estimation and proactive > > reclaim. These features are required to optimize job scheduling (bin > > packing) in data centers [1][2]. > > debugfs is for ephemeral temp stuf which can and will change or > disappear at any time. Anything which is "required" by userspace > should not be in debufgs. Right. "required" is probably a poor choice of words. "These techniques are commonly used to optimize job scheduling" would sound better. > Presumably sysfs is the place. Fully documented and with usage > examples in the changelog so we can carefully review the proposed > extensions to Linux's ABI. Extensions which must be maintained > unchanged for all time. Eventually, yes. There still is a long way to go. Rest assured, this is something Google will keep investing resources on.