From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754701Ab0ESITX (ORCPT ); Wed, 19 May 2010 04:19:23 -0400 Received: from casper.infradead.org ([85.118.1.10]:46796 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752177Ab0ESITU convert rfc822-to-8bit (ORCPT ); Wed, 19 May 2010 04:19:20 -0400 Subject: Re: [tip:perf/core] perf/ftrace: Optimize perf/tracepoint interaction for single events From: Peter Zijlstra To: Frederic Weisbecker Cc: mingo@redhat.com, hpa@zytor.com, paulus@samba.org, acme@redhat.com, linux-kernel@vger.kernel.org, efault@gmx.de, rostedt@goodmis.org, tglx@linutronix.de, mingo@elte.hu, linux-tip-commits@vger.kernel.org In-Reply-To: <20100519075804.GF5704@nowhere> References: <20100519075804.GF5704@nowhere> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Date: Wed, 19 May 2010 10:18:43 +0200 Message-ID: <1274257123.5605.10260.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2010-05-19 at 09:58 +0200, Frederic Weisbecker wrote: > On Tue, May 18, 2010 at 05:15:42PM +0000, tip-bot for Peter Zijlstra wrote: > > Commit-ID: 4f41c013f553957765902fb01475972f0af3e8e7 > > Gitweb: http://git.kernel.org/tip/4f41c013f553957765902fb01475972f0af3e8e7 > > Author: Peter Zijlstra > > AuthorDate: Tue, 18 May 2010 18:08:32 +0200 > > Committer: Ingo Molnar > > CommitDate: Tue, 18 May 2010 18:35:46 +0200 > > > > perf/ftrace: Optimize perf/tracepoint interaction for single events > > > > When we've got but a single event per tracepoint > > there is no reason to try and multiplex it so don't. > > > I haven't seen this patch going. > > But yeah that's a nice optimization for UP machines. Uhm, doesn't have anything to do with UP machines... it works quite well on SMP as well. Its about tracepoints with a single event attached.