Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757248Ab0GRUGN (ORCPT ); Sun, 18 Jul 2010 16:06:13 -0400 Received: from arkanian.console-pimps.org ([212.110.184.194]:39268 "EHLO arkanian.console-pimps.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757209Ab0GRUGN (ORCPT ); Sun, 18 Jul 2010 16:06:13 -0400 From: Matt Fleming To: Peter Zijlstra Cc: Gui Jianfeng , Yanmin Zhang , mingo@elte.hu, linux kernel mailing list , Paul Mundt , Arnaldo Carvalho de Melo Subject: Re: [PATCH 2/3] perf: Remove dead code in buildin-record.c In-Reply-To: <87pqzd3jx5.fsf@linux-g6p1.site> References: <4C241140.9090008@cn.fujitsu.com> <4C24119B.60200@cn.fujitsu.com> <20100625131356.GB4078@ghostprotocols.net> <1277477285.32034.666.camel@twins> <87pqzd3jx5.fsf@linux-g6p1.site> User-Agent: Notmuch/0.3.1-61-g3f63bb6 (http://notmuchmail.org) Emacs/23.1.90.2 (x86_64-unknown-linux-gnu) Date: Sun, 18 Jul 2010 21:06:11 +0100 Message-ID: <87hbjwzhak.fsf@linux-g6p1.site> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1259 Lines: 26 On Sat, 26 Jun 2010 16:14:46 +0100, Matt Fleming wrote: > On Fri, 25 Jun 2010 16:48:05 +0200, Peter Zijlstra wrote: > > > > Ah, yes, it would be nice for SH (which doesn't have a PMI) to couple a > > software timer with their hardware counter to get samples. > > > > Never got around to actually implementing that though, maybe Paul has a > > minion interested in making that work? > > I'll take a look at it. How does the 'group_fd' parameter relate to the lack of PMI? Is the idea to have one hrtimer that, when it fires, we sample all the counters? So the first counter to be created is the group leader, which starts the hrtimer, and all other counters are linked to this one? I had a go at using a hrtimer per counter (minus any weighting of samples) and it worked OK and seemed sensible given that we may want to sample counters at different frequencies. Is this what you had in mind with the 'group_fd' paramter, Peter? That there'd be only one hrtimer? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/