From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754870Ab1LFVxS (ORCPT ); Tue, 6 Dec 2011 16:53:18 -0500 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:33755 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752988Ab1LFVxR (ORCPT ); Tue, 6 Dec 2011 16:53:17 -0500 Message-ID: <4EDE8EBD.2070104@fb.com> Date: Tue, 6 Dec 2011 13:53:01 -0800 From: Arun Sharma User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:8.0) Gecko/20111105 Thunderbird/8.0 MIME-Version: 1.0 To: Peter Zijlstra CC: Stephane Eranian , , William Cohen , Vince Weaver , Subject: Re: [RFC][PATCH 0/6] perf: x86 RDPMC and RDTSC support References: <20111121145114.049265181@chello.nl> <4ED9267F.10106@fb.com> <4EDD26B9.8070007@fb.com> <4EDD50F5.30300@fb.com> <1323164549.32012.50.camel@twins> In-Reply-To: <1323164549.32012.50.camel@twins> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.18.252] X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.5.7110,1.0.211,0.0.0000 definitions=2011-12-06_04:2011-12-06,2011-12-06,1970-01-01 signatures=0 X-Proofpoint-Spam-Reason: safe Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/6/11 1:42 AM, Peter Zijlstra wrote: > On Mon, 2011-12-05 at 15:17 -0800, Arun Sharma wrote: >> >> I suspect that some optimizations are possible in perf_rotate_context >> that don't involve enabling/disabling the PMU via an IPI for simple >> cases that involve one or two hardware events (eg: fixed counters). > > I've got a patch queued that does exactly that. Verified that this fixes the lat_ctx regression. Thanks. -Arun