Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753503Ab3FDJib (ORCPT ); Tue, 4 Jun 2013 05:38:31 -0400 Received: from merlin.infradead.org ([205.233.59.134]:49703 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752717Ab3FDJiX (ORCPT ); Tue, 4 Jun 2013 05:38:23 -0400 Date: Tue, 4 Jun 2013 11:38:02 +0200 From: Peter Zijlstra To: Alexander Gordeev Cc: linux-kernel@vger.kernel.org, x86@kernel.org, Thomas Gleixner , Ingo Molnar , Arnaldo Carvalho de Melo , Jiri Olsa , Frederic Weisbecker Subject: Re: [PATCH RFC -tip 0/6] perf: IRQ-bound performance events Message-ID: <20130604093802.GK8923@twins.programming.kicks-ass.net> References: <20130603094132.GB30878@dhcp-26-207.brq.redhat.com> <20130603133618.GK30878@dhcp-26-207.brq.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130603133618.GK30878@dhcp-26-207.brq.redhat.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1336 Lines: 32 On Mon, Jun 03, 2013 at 03:36:19PM +0200, Alexander Gordeev wrote: > On Mon, Jun 03, 2013 at 11:41:32AM +0200, Alexander Gordeev wrote: > > # ./tools/perf/perf stat -I 8 -a -e L1-dcache-load-misses:k sleep 1 > > > > Performance counter stats for process id '8': > > > > 0 L1-dcache-load-misses > > > > 1.001235781 seconds time elapsed > > > > # ./tools/perf/perf stat -I 8 -a -e L1-dcache-load-misses:k hwclock --test > > Mon 03 Jun 2013 04:42:59 AM EDT -0.891274 seconds > > > > Performance counter stats for process id '8': > > Oops, the most interesting part did not make it in. Very sorry :) Here: > > # ./tools/perf/perf stat -I 8 -a -e L1-dcache-load-misses:k hwclock --test > Mon 03 Jun 2013 09:32:49 AM EDT -0.719514 seconds > > Performance counter stats for process id '8': > > 447 L1-dcache-load-misses I think that is very much expected; except in the case where you spend _all_ your time in IRQ handlers, they'll pretty much always miss l1 cache. -- 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/