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 C8134C32751 for ; Wed, 7 Aug 2019 20:44:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8B4D720880 for ; Wed, 7 Aug 2019 20:44:54 +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 S2389168AbfHGUox (ORCPT ); Wed, 7 Aug 2019 16:44:53 -0400 Received: from mail-pl1-f196.google.com ([209.85.214.196]:32865 "EHLO mail-pl1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729934AbfHGUox (ORCPT ); Wed, 7 Aug 2019 16:44:53 -0400 Received: by mail-pl1-f196.google.com with SMTP id c14so42433443plo.0 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=rMIBOBfxDzTew06fEYchXHDArvYG1jsTtphhY+k+F4S5gw6PdmEgAbpE5oc64zsxqI i4ugT/7tqko1BfpAd8vM6miwqf7lwKbMuiF+iPkNUqAYOgaVUwOi41/+AX+WnUa5AflK GAkSesd1DikyQgKK3qbP1xSA/H82viBgni9JHN2GNBrQBnpsyhIIowdZoItdijQ4ldvv RhKz7i4uxbHzg4B5BQXVkxnWxegP4ad7LUasWBVxe8pbf/UtJ0ROZDZc0zE3JE7ZkGKd +7ETcTWaOnafAxdGnoaevTXgtePb60qarXqfvpZshGR1wn+9+wDAXlXKoVaskdK5TyKo m33w== X-Gm-Message-State: APjAAAX5Dfeptvw/bcMaOJfi2m0Tm2UG4zQtDuisPW6Rt3P5MtEW4JLl 5jvrOO6M2ighFGb9vJXA9zhTDg== 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-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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