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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 40D70C32751 for ; Wed, 7 Aug 2019 20:44:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 181E3217F4 for ; Wed, 7 Aug 2019 20:44:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=joelfernandes.org header.i=@joelfernandes.org header.b="cvR0USsq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387967AbfHGUox (ORCPT ); Wed, 7 Aug 2019 16:44:53 -0400 Received: from mail-pl1-f196.google.com ([209.85.214.196]:36344 "EHLO mail-pl1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729804AbfHGUox (ORCPT ); Wed, 7 Aug 2019 16:44:53 -0400 Received: by mail-pl1-f196.google.com with SMTP id k8so42530738plt.3 for ; Wed, 07 Aug 2019 13:44:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=joelfernandes.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=itaaHUuDhcUmWvWTJL4zW8mOnytMPij6pAOeeM3m1Hg=; b=cvR0USsq4TrVGI/7AHhxTvBLliSSP311yfq2eMIv0HZPy5zvZSgUkA9hOQuqwUwOmK tW59Vs41S3Z4cN2lbD7CBiabk1kuZyNcNbwelUz8x6sT4Q/qw4los5KJ1TsmL/bCkQ6a NbDSeg5PosKj8KNSTPFRKtihsP13TwsNRRQSw= 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:in-reply-to:user-agent; bh=itaaHUuDhcUmWvWTJL4zW8mOnytMPij6pAOeeM3m1Hg=; b=VwhTZ9594YSQ3eqk3SF6gqCoSvBClV9vZSJcXTfQ+nsO4LslZEz3LCzxBRmk0pnCgV 4G9lgSr3BHsvcYaB93ZpmNtKA2R8ymLs4NSklbDi627/pgpW9xBye4HgdyP9FI3qSe9v xjWq2radzBnTalji0hq/mRztBoXu44kbVKKERGZMBbLNXPImUyeZFEtTOxklRVbNsZbz vjKWa52LgICdaBcxgp/cxpk1EkOlWFHx7ZX1jQV/Kcq9KW1CLS3Uaz66iKlHWwUaCsgm vtxkZyaTiF0obLVGj9UOzybijH6GoARQtishA/26V0MPxCekLtxRIelTDoV9IzYYypHz Ap2Q== X-Gm-Message-State: APjAAAUcwMxiBRUe3v+B4gT9YDoTrvyo/8Gu44DcylDHgJ9BQOOOx0Iv lJ/og6QK6fWbW47a2i0gCELZTg== X-Google-Smtp-Source: APXvYqzxGRsJN8tg0/I87Pfq2FlyH6V5p4w6lM9eq6TQXsCKYWlpRWdYAkMSEIlSnT6YRM40KG3l1w== X-Received: by 2002:a17:90a:bb8a:: with SMTP id v10mr319911pjr.78.1565210692050; Wed, 07 Aug 2019 13:44:52 -0700 (PDT) Received: from localhost ([2620:15c:6:12:9c46:e0da:efbf:69cc]) by smtp.gmail.com with ESMTPSA id j1sm126143263pgl.12.2019.08.07.13.44.50 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Wed, 07 Aug 2019 13:44:51 -0700 (PDT) Date: Wed, 7 Aug 2019 16:44:49 -0400 From: Joel Fernandes To: Andrew Morton Cc: linux-kernel@vger.kernel.org, Alexey Dobriyan , Borislav Petkov , Brendan Gregg , Catalin Marinas , Christian Hansen , dancol@google.com, fmayer@google.com, "H. Peter Anvin" , Ingo Molnar , Jonathan Corbet , Kees Cook , kernel-team@android.com, linux-api@vger.kernel.org, linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Michal Hocko , Mike Rapoport , minchan@kernel.org, namhyung@google.com, paulmck@linux.ibm.com, Robin Murphy , Roman Gushchin , Stephen Rothwell , surenb@google.com, Thomas Gleixner , tkjos@google.com, Vladimir Davydov , Vlastimil Babka , Will Deacon , Brendan Gregg Subject: Re: [PATCH v4 1/5] mm/page_idle: Add per-pid idle page tracking using virtual indexing Message-ID: <20190807204449.GA90900@google.com> References: <20190805170451.26009-1-joel@joelfernandes.org> <20190806151921.edec128271caccb5214fc1bd@linux-foundation.org> <20190807100013.GC169551@google.com> <20190807130122.f148548c05ec07e7b716457e@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190807130122.f148548c05ec07e7b716457e@linux-foundation.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, Aug 07, 2019 at 01:01:22PM -0700, Andrew Morton wrote: > On Wed, 7 Aug 2019 06:00:13 -0400 Joel Fernandes wrote: > > > > > 8 files changed, 376 insertions(+), 45 deletions(-) > > > > > > Quite a lot of new code unconditionally added to major architectures. > > > Are we confident that everyone will want this feature? > > > > I did not follow, could you clarify more? All of this diff stat is not to > > architecture code: > > > My point is that the patchset adds a lot of new code with no way in > which users can opt out. Almost everyone gets a fatter kernel - how > many of those users will actually benefit from it? > > If "not many" then shouldn't we be making it Kconfigurable? Almost all of this code is already configurable with CONFIG_IDLE_PAGE_TRACKING. If you disable it, then all of this code gets disabled. Or are you referring to something else that needs to be made configurable? > Are there userspace tools which present this info to users or which > provide monitoring of some form? Do major distros ship those tools? > Do people use them? etcetera. > Android's heapprofd is what I was working on which is already using it (patch is not yet upstreamed). There is working set tracking which Sandeep (also from Android) said he wants to use. Minchan plans to use this in combination with ZRAM-based idle tracking. Mike Rappoport also showed some interest, but I am not sure where/how he is using it. These are just some of the usecases I am aware off. I am pretty sure more will come as well. thanks, - Joel