From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758409Ab0DAQiu (ORCPT ); Thu, 1 Apr 2010 12:38:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:24405 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758427Ab0DAQin (ORCPT ); Thu, 1 Apr 2010 12:38:43 -0400 Message-ID: <4BB4C0F5.3070204@redhat.com> Date: Thu, 01 Apr 2010 18:51:17 +0300 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.8) Gecko/20100301 Fedora/3.0.3-1.fc12 Thunderbird/3.0.3 MIME-Version: 1.0 To: Andrea Arcangeli CC: Peter Zijlstra , Thomas Gleixner , Rik van Riel , linux-kernel@vger.kernel.org, akpm@linux-foundation.org, Kent Overstreet , Ingo Molnar Subject: Re: [COUNTERPATCH] mm: avoid overflowing preempt_count() in mmu_take_all_locks() References: <1270117906.1653.139.camel@laptop> <4BB47FC3.1020606@redhat.com> <4BB480CC.2060503@redhat.com> <1270121264.1653.205.camel@laptop> <1270122194.1653.223.camel@laptop> <20100401154249.GQ5825@random.random> In-Reply-To: <20100401154249.GQ5825@random.random> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/01/2010 06:42 PM, Andrea Arcangeli wrote: > On Thu, Apr 01, 2010 at 01:43:14PM +0200, Peter Zijlstra wrote: > >> On Thu, 2010-04-01 at 13:27 +0200, Peter Zijlstra wrote: >> >>> I've almost got a patch done that converts those two, still need to look >>> where that tasklist_lock muck happens. >>> >> OK, so the below builds and boots, only need to track down that >> tasklist_lock nesting, but I got to run an errand first. >> > You should have a look at my old patchset where Christoph already > implemented this (and not for decreasing latency but to allow > scheduling in mmu notifier handlers, only needed by XPMEM): > > http://www.kernel.org/pub/linux/kernel/people/andrea/patches/v2.6/2.6.26-rc7/mmu-notifier-v18/ > > The ugliest part of it (that I think you missed below) is the breakage > of the RCU locking in the anon-vma which requires adding refcounting > to it. That was the worst part of the conversion as far as I can tell. > > http://www.kernel.org/pub/linux/kernel/people/andrea/patches/v2.6/2.6.26-rc7/mmu-notifier-v18/anon-vma > Can we use srcu now instead? -- error compiling committee.c: too many arguments to function