From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752999Ab1HAMoo (ORCPT ); Mon, 1 Aug 2011 08:44:44 -0400 Received: from mail-pz0-f42.google.com ([209.85.210.42]:62002 "EHLO mail-pz0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752786Ab1HAMoi (ORCPT ); Mon, 1 Aug 2011 08:44:38 -0400 Message-ID: <4E369FB4.3070603@gmail.com> Date: Mon, 01 Aug 2011 06:44:36 -0600 From: David Ahern User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.18) Gecko/20110621 Fedora/3.1.11-1.fc15 Thunderbird/3.1.11 MIME-Version: 1.0 To: Benjamin Herrenschmidt CC: Peter Zijlstra , anton@samba.org, acme@ghostprotocols.net, mingo@elte.hu, paulus@samba.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] perf: powerpc: Disable pagefaults during callchain stack read References: <1312059200-11563-1-git-send-email-dsahern@gmail.com> <1312192792.2617.381.camel@laptop> <1312195147.8793.794.camel@pasglop> In-Reply-To: <1312195147.8793.794.camel@pasglop> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/01/2011 04:39 AM, Benjamin Herrenschmidt wrote: > On Mon, 2011-08-01 at 11:59 +0200, Peter Zijlstra wrote: >>> Signed-off-by: David Ahern >>> CC: Benjamin Herrenschmidt >>> CC: Anton Blanchard >> >> Hmm, Paul, didn't you fix something like this early on? Anyway, I've >> no >> objections since I'm really not familiar enough with the PPC side of >> things. > > I'm travelling so I haven't had a chance to review properly or even test > but it looks like an ad-hoc fix for the immediate problem. > > Ultimately, I want to rework that stuff to do a __gup_fast like x86 does > (maybe as a fallback from an attempt at access first) so we work around > access permissions blocked by lack of dirty/accessed bits but in the > meantime, this should fix the immediate issue. The problem goes back to all kernel releases with perf, so this patch should get applied to the stable trains too. David > > Cheers, > Ben. > >