From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751788AbbALIUg (ORCPT ); Mon, 12 Jan 2015 03:20:36 -0500 Received: from lgeamrelo02.lge.com ([156.147.1.126]:52973 "EHLO lgeamrelo02.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751286AbbALIUf (ORCPT ); Mon, 12 Jan 2015 03:20:35 -0500 X-Original-SENDERIP: 10.177.222.153 X-Original-MAILFROM: iamjoonsoo.kim@lge.com Date: Mon, 12 Jan 2015 17:20:57 +0900 From: Joonsoo Kim To: Mel Gorman Cc: Vlastimil Babka , Andrew Morton , David Rientjes , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/3] mm/compaction: enhance trace output to know more about compaction internals Message-ID: <20150112082057.GA26078@js1304-P5Q-DELUXE> References: <1417593127-6819-1-git-send-email-iamjoonsoo.kim@lge.com> <54ABA563.1040103@suse.cz> <20150108081835.GC25453@js1304-P5Q-DELUXE> <54AE43E3.60209@suse.cz> <20150109105710.GN2395@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150109105710.GN2395@suse.de> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 09, 2015 at 10:57:10AM +0000, Mel Gorman wrote: > On Thu, Jan 08, 2015 at 09:46:27AM +0100, Vlastimil Babka wrote: > > On 01/08/2015 09:18 AM, Joonsoo Kim wrote: > > > On Tue, Jan 06, 2015 at 10:05:39AM +0100, Vlastimil Babka wrote: > > >> On 12/03/2014 08:52 AM, Joonsoo Kim wrote: > > >> > It'd be useful to know where the both scanner is start. And, it also be > > >> > useful to know current range where compaction work. It will help to find > > >> > odd behaviour or problem on compaction. > > >> > > >> Overall it looks good, just two questions: > > >> 1) Why change the pfn output to hexadecimal with different printf layout and > > >> change the variable names and? Is it that better to warrant people having to > > >> potentially modify their scripts parsing the old output? > > > > > > Deciaml output has really bad readability since we manage all pages by order > > > of 2 which is well represented by hexadecimal. With hex output, we can > > > easily notice whether we move out from one pageblock to another one. > > > > OK. I don't have any strong objection, maybe Mel should comment on this as the > > author of most of the tracepoints? But if it happens, I think converting the old > > tracepoints to new hexadecimal format should be a separate patch from adding the > > new ones. > > > > To date, I'm not aware of any user-space programs that heavily depend on > the formatting. The scripts I am aware of are ad-hoc and easily modified > to adapt to format changes. LTT-NG is the only tool that might be > depending on trace point formats but I severely doubt it's interested in > this particular tracepoint. Okay. Thanks for confirmation! Thanks.