Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755797Ab3ENA4I (ORCPT ); Mon, 13 May 2013 20:56:08 -0400 Received: from LGEMRELSE7Q.lge.com ([156.147.1.151]:61561 "EHLO LGEMRELSE7Q.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755657Ab3ENA4G (ORCPT ); Mon, 13 May 2013 20:56:06 -0400 X-AuditID: 9c930197-b7b76ae000003523-21-51918ba44a32 From: Namhyung Kim To: Andi Kleen Cc: Arnaldo Carvalho de Melo , Peter Zijlstra , Paul Mackerras , Ingo Molnar , Namhyung Kim , LKML , Jiri Olsa , David Ahern , Stephane Eranian Subject: Re: [PATCH 1/2] perf report: Add --percent-limit option References: <1368434503-29373-1-git-send-email-namhyung@kernel.org> <20130513141117.GC17814@two.firstfloor.org> Date: Tue, 14 May 2013 09:56:04 +0900 In-Reply-To: <20130513141117.GC17814@two.firstfloor.org> (Andi Kleen's message of "Mon, 13 May 2013 16:11:17 +0200") Message-ID: <87hai65qhn.fsf@sejong.aot.lge.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.1 (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: 1431 Lines: 38 Hi Andi, On Mon, 13 May 2013 16:11:17 +0200, Andi Kleen wrote: > On Mon, May 13, 2013 at 05:41:42PM +0900, Namhyung Kim wrote: >> From: Namhyung Kim >> >> The --percent-limit option is for not showing small overheaded entries >> in the output. Maybe we want to set a certain default value like 0.1. >> >> Cc: Andi Kleen > > I like the option, but 0 is not a good default. > Make it 1 or something. Thanks. I just wanted to reserve same behavior since I didn't know what's the reasonable default value. We might use a config variable for this to customize the default value. > > Perhaps a better heuristic would be > percent < threshold || samples < sample-threshold > with sample-threshold being several hundred at least. > > A very small number of hits on something is usually quite much useless, > unless your original event was extremly rare in the beginning > (but then it's unclear if the profile is any useful) Looks reasonable, but I know there's also some users who use the perf tools lightly. A several hundreds sample-threshold looks too harsh to them IMHO. In addition, it should handle tracepoints. 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/