From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pb0-f42.google.com (mail-pb0-f42.google.com [209.85.160.42]) by kanga.kvack.org (Postfix) with ESMTP id 905FB6B0031 for ; Sun, 27 Oct 2013 12:13:31 -0400 (EDT) Received: by mail-pb0-f42.google.com with SMTP id jt11so5425619pbb.15 for ; Sun, 27 Oct 2013 09:13:31 -0700 (PDT) Received: from psmtp.com ([74.125.245.124]) by mx.google.com with SMTP id gj2si10680509pac.167.2013.10.27.09.13.28 for ; Sun, 27 Oct 2013 09:13:29 -0700 (PDT) Received: by mail-pb0-f73.google.com with SMTP id rr13so350340pbb.0 for ; Sun, 27 Oct 2013 09:13:27 -0700 (PDT) From: Greg Thelen Subject: Re: [PATCH 2/3] percpu counter: cast this_cpu_sub() adjustment References: <1382859876-28196-1-git-send-email-gthelen@google.com> <1382859876-28196-3-git-send-email-gthelen@google.com> <20131027112255.GB14934@mtj.dyndns.org> <20131027050429.7fcc2ed5.akpm@linux-foundation.org> <20131027130036.GN14934@mtj.dyndns.org> Date: Sun, 27 Oct 2013 09:13:25 -0700 In-Reply-To: <20131027130036.GN14934@mtj.dyndns.org> (Tejun Heo's message of "Sun, 27 Oct 2013 09:00:36 -0400") Message-ID: MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: Tejun Heo Cc: Andrew Morton , Christoph Lameter , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Johannes Weiner , Michal Hocko , Balbir Singh , KAMEZAWA Hiroyuki , handai.szj@taobao.com, x86@kernel.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org On Sun, Oct 27 2013, Tejun Heo wrote: > On Sun, Oct 27, 2013 at 05:04:29AM -0700, Andrew Morton wrote: >> On Sun, 27 Oct 2013 07:22:55 -0400 Tejun Heo wrote: >> >> > We probably want to cc stable for this and the next one. How should >> > these be routed? I can take these through percpu tree or mm works >> > too. Either way, it'd be best to route them together. >> >> Yes, all three look like -stable material to me. I'll grab them later >> in the week if you haven't ;) > > Tried to apply to percpu but the third one is a fix for a patch which > was added to -mm during v3.12-rc1, so these are yours. :) I don't object to stable for the first two non-memcg patches, but it's probably unnecessary. I should have made it more clear, but an audit of v3.12-rc6 shows that only new memcg code is affected - the new mem_cgroup_move_account_page_stat() is the only place where an unsigned adjustment is used. All other callers (e.g. shrink_dcache_sb) already use a signed adjustment, so no problems before v3.12. Though I did not audit the stable kernel trees, so there could be something hiding in there. >> The names of the first two patches distress me. They rather clearly >> assert that the code affects percpu_counter.[ch], but that is not the case. >> Massaging is needed to fix that up. > > Yeah, something like the following would be better > > percpu: add test module for various percpu operations > percpu: fix this_cpu_sub() subtrahend casting for unsigneds > memcg: use __this_cpu_sub() to dec stats to avoid incorrect subtrahend casting No objection to renaming. Let me know if you want these reposed with updated titles. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org