From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753105Ab1AXVZx (ORCPT ); Mon, 24 Jan 2011 16:25:53 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:58411 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751554Ab1AXVZw (ORCPT ); Mon, 24 Jan 2011 16:25:52 -0500 Date: Mon, 24 Jan 2011 22:25:26 +0100 From: Ingo Molnar To: Arnaldo Carvalho de Melo Cc: Linus Torvalds , linux-kernel@vger.kernel.org, Peter Zijlstra , =?iso-8859-1?Q?Fr=E9d=E9ric?= Weisbecker , Steven Rostedt , Thomas Gleixner , Andrew Morton Subject: Re: [GIT PULL] perf fixes Message-ID: <20110124212526.GA13724@elte.hu> References: <20110124133400.GA1228@elte.hu> <20110124200738.GA10833@elte.hu> <20110124203802.GC29975@ghostprotocols.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110124203802.GC29975@ghostprotocols.net> 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 * Arnaldo Carvalho de Melo wrote: > Em Tue, Jan 25, 2011 at 06:27:31AM +1000, Linus Torvalds escreveu: > > On Tue, Jan 25, 2011 at 6:17 AM, Linus Torvalds > > wrote: > > > > > > It only happens for me with "g". With "perf record -af sleep 10" it worked. > > > > Actually, it's something subtler than that. It must depend on the > > actual data, because now when I tried it again, it worked with 'g' > > too. I hadn't saved the old perf.data that caused the lockup (it got > > overwritten by the non-g test), and now when I try to re-create it it > > doesn't hang on the result. > > > > So it's probably some very specific data pattern that causes it. > > > > (And I don't know if it's a hard hang - it could just be something > > _very_ slow. But we're talking half a minute kind of slow). > > Was this on a freshly installed machine? Or on a freshly updated one? > > Probably its the build-id collecting at the end of a session, on the > first run you had a cold cache and it had to figure out which binaries > to cache on ~/.debug, second time it was already cached so it was fast. Hm, it would be nice to not surprise users with an unlimited-timeout, up to half a minute 'frozen' app. Can we possibly display a more finegrained progress indicator? Thanks, Ingo