From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 598BDB6F98 for ; Mon, 1 Aug 2011 20:39:56 +1000 (EST) Subject: Re: [PATCH] perf: powerpc: Disable pagefaults during callchain stack read From: Benjamin Herrenschmidt To: Peter Zijlstra In-Reply-To: <1312192792.2617.381.camel@laptop> References: <1312059200-11563-1-git-send-email-dsahern@gmail.com> <1312192792.2617.381.camel@laptop> Content-Type: text/plain; charset="UTF-8" Date: Mon, 01 Aug 2011 20:39:07 +1000 Message-ID: <1312195147.8793.794.camel@pasglop> Mime-Version: 1.0 Cc: linux-kernel@vger.kernel.org, paulus@samba.org, anton@samba.org, acme@ghostprotocols.net, David Ahern , mingo@elte.hu, linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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. Cheers, Ben.