From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753232Ab2CEPsg (ORCPT ); Mon, 5 Mar 2012 10:48:36 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:54557 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752981Ab2CEPsf (ORCPT ); Mon, 5 Mar 2012 10:48:35 -0500 Date: Mon, 5 Mar 2012 16:47:53 +0100 From: Ingo Molnar To: Stephane Eranian Cc: linux-kernel@vger.kernel.org, acme@redhat.com, peterz@infradead.org, dsahern@gmail.com, ravitillo@lbl.gov, khandual@linux.vnet.ibm.com, asharma@fb.com, robert.richter@amd.com, ming.m.lin@intel.com, vweaver1@eecs.utk.edu, andi@firstfloor.org, Peter Zijlstra Subject: Re: [PATCH] perf report: auto-detect branch stack sampling mode Message-ID: <20120305154753.GA14604@elte.hu> References: <20120224094048.GA7952@quad> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120224094048.GA7952@quad> User-Agent: Mutt/1.5.21 (2010-09-15) 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=AWL,BAYES_00 autolearn=no SpamAssassin version=3.3.1 -2.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] 0.0 AWL AWL: From: address is in the auto white-list Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Another usability bug of the new branch sampling feature is that typing the obvious: $ perf record -b ./myprog does not do the obvious thing and default to 'any' but throws a *very* unhelpful generic perf error: usage: perf record [] [] or: perf record [] -- [] ... Really, we should do better than this. Only people who *want* to specify finer LBR filters should be forced to specify them. Thanks, Ingo