From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ingo Molnar Subject: Re: [pchecks v2 2/2] percpu: Add preemption checks to __this_cpu ops Date: Sat, 28 Sep 2013 10:44:12 +0200 Message-ID: <20130928084412.GC26167@gmail.com> References: <20130924154159.855373283@linux.com> <0000014150a21408-2d759c49-6a9e-4553-956f-2d4b53e710f8-000000@email.amazonses.com> <20130924171029.GB10261@gmail.com> <0000014155fdd6cf-d54da8b8-2198-40ce-8831-4559971e69f0-000000@email.amazonses.com> <20130925181146.GA16693@gmail.com> <000001415fb34afc-79a24112-5d3f-431c-b90c-d6cfa1caf27a-000000@email.amazonses.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-ea0-f177.google.com ([209.85.215.177]:54258 "EHLO mail-ea0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753048Ab3I1IoQ (ORCPT ); Sat, 28 Sep 2013 04:44:16 -0400 Content-Disposition: inline In-Reply-To: <000001415fb34afc-79a24112-5d3f-431c-b90c-d6cfa1caf27a-000000@email.amazonses.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Christoph Lameter Cc: Tejun Heo , akpm@linuxfoundation.org, linux-arch@vger.kernel.org, Steven Rostedt , linux-kernel@vger.kernel.org, Peter Zijlstra , Thomas Gleixner , Peter Zijlstra * Christoph Lameter wrote: > > The blind __this_cpu conversions without proper preempt debugging > > cannot continue without first fixing all the fallout of the missing > > debug checks to begin with. > > That will take some time as the feedback from the other patchset > suggests. That's the reason why we insisted on __this_cpu*() primitives growing these essential debug checks early on - which you resisted. I had to bring out NAKs for you to see sense and start fixing the mess already - next time around I'll probably have to NAK your changes earlier to prevent such mishaps. ( Note that some false positives were possibly fixed by the use of the lib/smp_processor_id.c methods to check for preemptability, so the situation might not be as dire as your first series suggests. ) Thanks, Ingo