From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751820AbaEGRaP (ORCPT ); Wed, 7 May 2014 13:30:15 -0400 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:51289 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750884AbaEGRaM (ORCPT ); Wed, 7 May 2014 13:30:12 -0400 Date: Wed, 7 May 2014 18:29:24 +0100 From: Will Deacon To: Vince Weaver Cc: Peter Zijlstra , Chad Paradis , "linux-kernel@vger.kernel.org" , Paul Mackerras , Ingo Molnar , Arnaldo Carvalho de Melo , Stephane Eranian Subject: Re: [patch/rfc] perf on raspberry-pi without overflow interrupt Message-ID: <20140507172924.GE3694@arm.com> References: <20140109101921.GA26435@mudshark.cambridge.arm.com> <20140110094056.GK31570@twins.programming.kicks-ass.net> <20140114105721.GU7572@laptop.programming.kicks-ass.net> <20140116173110.GA9655@laptop.programming.kicks-ass.net> <20140224104634.GA2553@mudshark.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Vince, On Mon, Feb 24, 2014 at 03:37:11PM +0000, Vince Weaver wrote: > On Mon, 24 Feb 2014, Will Deacon wrote: > > On Fri, Jan 17, 2014 at 05:45:04AM +0000, Vince Weaver wrote: > > > On Thu, 16 Jan 2014, Peter Zijlstra wrote: > > > > > > > Yeah I suppose we could do something like that. Maybe something like: > > > > > > > > # cat /sys/bus/event_source/devices/cpu/flags > > > > int precise filter > > > > > > wouldn't that violate the "one value per file" rule? > > > > > > I guess we could also stick it in the mmap page somewhere, as tools like > > > PAPI already have to check there for things like rdpmc support. > > > > > > > > > Anyway, here's a first pass at a generic fix for this issue. I'm sure the > > > code is pretty horrible, I don't usually mess with the perf code at this > > > level. I haven't tested yet as it touched enough files that the rasp-pi > > > is going to take a few hours to finish compiling. > > > > > > Am I on the right track, or totally off here? > > > > Where did we get to with this? If the generic changes are going to take some > > time, I'm happy to take a temporary (non-invasive) fix in the ARM backend while > > you sort out the core. > > OK, let me revisit the patches. The last set of generic ones I sent out > actually was broken on ARM and I've been meaning to straighten things out > and send a proper follow up patch set but got distracted by other perf > related issues. Any luck with this? I just got (another) report of a PMU with borked interrupts, so a fix would be great if you've got one. Will