From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757890AbZHGNB1 (ORCPT ); Fri, 7 Aug 2009 09:01:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757875AbZHGNB1 (ORCPT ); Fri, 7 Aug 2009 09:01:27 -0400 Received: from viefep19-int.chello.at ([62.179.121.39]:58611 "EHLO viefep19-int.chello.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757874AbZHGNB0 (ORCPT ); Fri, 7 Aug 2009 09:01:26 -0400 X-SourceIP: 213.93.53.227 Subject: Re: perf-record fix and UI improvement From: Peter Zijlstra To: Pierre Habouzit Cc: Ingo Molnar , Paul Mackerras , linux-kernel@vger.kernel.org In-Reply-To: <1249647361-11582-1-git-send-email-pierre.habouzit@intersec.com> References: <1249647361-11582-1-git-send-email-pierre.habouzit@intersec.com> Content-Type: text/plain Date: Fri, 07 Aug 2009 15:01:06 +0200 Message-Id: <1249650066.32113.706.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.26.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2009-08-07 at 14:15 +0200, Pierre Habouzit wrote: > While toying with perf, I've noticed that perf record can easily enter > a busy loop when doing something as silly as: > > $ perf record -A ls > > I've searched why and here are the patches: > > [PATCH 1/2] perf util: do_read should fail on EOF instead of busy-looping. > > Yeah, do_read here really wants to read a known size, not being able > to should die(), not busy-lopp ;) > That was the cause for the bug. > > > [PATCH 2/2] perf-record: improve -A UI for empty or non-existent perf.data > > Though with 1/2 `git record -A ls` would then fail miserably with > some kind of "cannot read" error, which sucks. So this patch > understands -A as a "append or create if file is empty or inexistant" > > This fact may deserve to be documented properly, if so just tell me > I'll send an updated patch for Documentation/ > > > I'm kind of new to the kernel world, so I hope I sent the patches to the > proper persons. You did well for a first time ;-) The things you can improve for next time are: - placing these nice descriptions you made above into the patches themselves, as esp the first patch has an empty changelog. - get your email right :-) Anyway, I think Ingo already fixed that up for you, so Acked-by: Peter Zijlstra