From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752723AbZKOKe7 (ORCPT ); Sun, 15 Nov 2009 05:34:59 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752655AbZKOKe6 (ORCPT ); Sun, 15 Nov 2009 05:34:58 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:46475 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752609AbZKOKe6 (ORCPT ); Sun, 15 Nov 2009 05:34:58 -0500 Date: Sun, 15 Nov 2009 11:34:59 +0100 From: Ingo Molnar To: Simon K??mpflein , Peter Zijlstra , Mike Galbraith , Fr??d??ric Weisbecker Cc: linux-kernel@vger.kernel.org Subject: Re: perf counters: problem with perf record Message-ID: <20091115103459.GC24931@elte.hu> References: <4AFEE55B.3000906@gmx.de> <1258227980.30187.512.camel@laptop> <4AFFD2B8.5060400@gmx.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4AFFD2B8.5060400@gmx.de> User-Agent: Mutt/1.5.20 (2009-08-17) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -2.0 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 * Simon K??mpflein wrote: > Peter Zijlstra schrieb: > > On Sun, 2009-11-15 at 03:14 +1000, Simon K??mpflein wrote: > >> Hello, > >> > >> I have a problem with the new kernel perf tools in kernel 2.6.31.6 (very > >> nice tools by the way). I like to monitor the cache-misses of a program. > >> "perf stat -e cache-misses program" works without problems, but I can't > >> get "perf record -e cache-misses program" working (even running as root > >> and CONFIG_PERF_COUNTERS=y): > >> > >> Error: perfcounter syscall returned with -1 (Operation not supported) > >> Fatal: No CONFIG_PERF_COUNTERS=y kernel support configured? > >> > >> My CPU is a "Intel(R) Pentium(R) M processor 1.80GHz": > > > > Does the bootlog perchance contain the output of? > > > > if (!cpu_has_apic) { > > pr_info("no APIC, boot with the \"lapic\" boot parameter > > to force-enable it.\n"); > > pr_info("no hardware sampling interrupt available.\n"); > > x86_pmu.apic = 0; > > } > > Yes. I didn't realize that it has something to do with the Performance > Counters because I didn't see that it belongs to the Performance Counter > output. > Maybe it's a good idea to add another comment making it clear that the > performance counters are not fully working in this case. Or detect this > case in "perf-record" and output a message relating to that. Ok. Mind sending a patch that changes the message so that it explains it all to you more clearly? > > And does booting with the suggested lapic parameter cure your problems? > > > > Yes, thank you! Great. You might want to send another patch that allows the .config enabling of that lapic boot parameter. It sucks to carry around boot parameters. Ingo