Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756682AbZFZHYP (ORCPT ); Fri, 26 Jun 2009 03:24:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753805AbZFZHYA (ORCPT ); Fri, 26 Jun 2009 03:24:00 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:52381 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751398AbZFZHX7 (ORCPT ); Fri, 26 Jun 2009 03:23:59 -0400 Date: Fri, 26 Jun 2009 09:23:50 +0200 From: Ingo Molnar To: Peter Zijlstra Cc: Paul Mundt , Martin Schwidefsky , linux-kernel Subject: Re: register_timer_hook use in arch/sh/oprofile Message-ID: <20090626072350.GI14078@elte.hu> References: <20090624131104.705c828d@skybase> <20090624112929.GB2079@linux-sh.org> <20090624142828.7c6a2337@skybase> <20090624123416.GB9510@linux-sh.org> <20090624124542.GB32306@elte.hu> <20090624131440.GA9700@linux-sh.org> <20090624132447.GD6224@elte.hu> <1245999685.31755.157.camel@twins> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1245999685.31755.157.camel@twins> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 899 Lines: 26 * Peter Zijlstra wrote: > On Wed, 2009-06-24 at 15:24 +0200, Ingo Molnar wrote: > > > > [ And long-term analysis ('perf stat' type of runs) dont need IRQs > > anyway - perfcounters reads outs the counts and summarizes them > > across the measured workload. ] > > If the counter width is less than 64 bits we do need to have some > interrupt to read them from before they cycle so we can accumulate > the deltas into a proper u64. Yeah - but even that can be driven from some housekeeping hrtimer. > But for proper 64 bit hardware counters there is indeed no need > for that. Indeed - although they are rare. Ingo -- 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/