From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755996Ab2HPKvo (ORCPT ); Thu, 16 Aug 2012 06:51:44 -0400 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:44996 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751255Ab2HPKvm (ORCPT ); Thu, 16 Aug 2012 06:51:42 -0400 Date: Thu, 16 Aug 2012 11:51:34 +0100 From: Will Deacon To: Arnd Bergmann Cc: Catalin Marinas , "linux-arch@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v2 25/31] arm64: Performance counters support Message-ID: <20120816105134.GJ31784@mudshark.cambridge.arm.com> References: <1344966752-16102-1-git-send-email-catalin.marinas@arm.com> <1344966752-16102-26-git-send-email-catalin.marinas@arm.com> <201208151511.11612.arnd@arndb.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201208151511.11612.arnd@arndb.de> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 15, 2012 at 04:11:11PM +0100, Arnd Bergmann wrote: > On Tuesday 14 August 2012, Catalin Marinas wrote: > > From: Will Deacon > > > > This patch adds support for the AArch64 performance counters. > > > > Signed-off-by: Will Deacon > > Signed-off-by: Catalin Marinas > > --- > > arch/arm64/include/asm/perf_event.h | 22 + > > arch/arm64/include/asm/pmu.h | 82 +++ > > arch/arm64/kernel/perf_event.c | 1368 +++++++++++++++++++++++++++++++++++ > > tools/perf/perf.h | 6 + > > Can you explain how AArch64 performance counters differ from the 32 > bit ones? Do they work for AArch32 user space under AArch64 kernels? > Is it possible to share parts of the implementation with arch/arm? Perf should work for compat tasks, yes. I'd like to share some of the code with arch/arm/ and I've started reworking the arch/arm/ stuff to accomodate this better: git://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git perf/updates I'm not sure how well it will fit in drivers/ but I'm certainly willing to give it a try. Will