Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750833Ab2EDEGv (ORCPT ); Fri, 4 May 2012 00:06:51 -0400 Received: from LGEMRELSE1Q.lge.com ([156.147.1.111]:52781 "EHLO LGEMRELSE1Q.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750714Ab2EDEGu (ORCPT ); Fri, 4 May 2012 00:06:50 -0400 X-AuditID: 9c93016f-b7c79ae0000006b3-af-4fa355d74159 From: Namhyung Kim To: Arnaldo Carvalho de Melo Cc: David Ahern , Peter Zijlstra , Paul Mackerras , Ingo Molnar , LKML Subject: Re: [PATCH 07/13] perf evlist: Fix creation of cpu map References: <1335417327-11796-1-git-send-email-namhyung.kim@lge.com> <1335417327-11796-8-git-send-email-namhyung.kim@lge.com> <4F996433.7040003@gmail.com> <1335474778.1497.14.camel@leonhard> <4F99BCAF.1080309@gmail.com> <87397qhvvx.fsf@sejong.aot.lge.com> <20120502184033.GD5745@infradead.org> Date: Fri, 04 May 2012 13:05:48 +0900 In-Reply-To: <20120502184033.GD5745@infradead.org> (Arnaldo Carvalho de Melo's message of "Wed, 2 May 2012 15:40:33 -0300") Message-ID: <87fwbga8v7.fsf@sejong.aot.lge.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.0.95 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1313 Lines: 36 Hi, On Wed, 2 May 2012 15:40:33 -0300, Arnaldo Carvalho de Melo wrote: > Em Fri, Apr 27, 2012 at 09:16:18AM +0900, Namhyung Kim escreveu: >> So as long as you set perf_event_paranoid to -1 or run perf test as >> root, you cannot see the failure. > > Ok, as root try 'perf top', here I get, with this patch: > > [root@sandy ~]# perf top --stdio > Warning: > The sys_perf_event_open() syscall returned with 22 (Invalid argument). > /bin/dmesg may provide additional information. > No CONFIG_PERF_EVENTS=y kernel support configured? > [root@sandy ~]# > > Skipping this one, will look again later. > > - Arnaldo Sorry. It is because perf top depends on an undefined behaviour that if neither target nor command line argument was specified it'd open events for all online cpus. In contrast, perf record and perf stat will show the help message in this case. This patch makes it clear that we have to prepare a sane target configuration before opening a perf event fd. So I think we should fix perf top to set top.target.system_wide to true by default. Thanks, Namhyung -- 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/