Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756960AbYBQOBE (ORCPT ); Sun, 17 Feb 2008 09:01:04 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755285AbYBQOAw (ORCPT ); Sun, 17 Feb 2008 09:00:52 -0500 Received: from www.tglx.de ([62.245.132.106]:50142 "EHLO www.tglx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755265AbYBQOAv (ORCPT ); Sun, 17 Feb 2008 09:00:51 -0500 Date: Sun, 17 Feb 2008 15:00:14 +0100 (CET) From: Thomas Gleixner To: Arnaldo Carvalho de Melo cc: Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: Reducing debuginfo size by removing unneeded includes In-Reply-To: <20080207230304.GA4352@ghostprotocols.net> Message-ID: References: <20080207230304.GA4352@ghostprotocols.net> User-Agent: Alpine 1.00 (LFD 882 2007-12-20) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1903 Lines: 51 On Thu, 7 Feb 2008, Arnaldo Carvalho de Melo wrote: > Hi Ingo, > > I'm starting with you because the first file I used to > experiment with this idea was arch/x86/ia32/sys_ia32.c. > > I found it strange that the struct sk_buff definition was found > inside the DWARF debugging sections in the generated object, so I verified > and found that there is no need for the files that bring struct sk_buff > definition into this file and verified also that sk_buff is not brought > in indirectly too, thru other headers. > > I went on and removed many other unneeded includes and the end > result is: > > [acme@doppio net-2.6]$ l /tmp/sys_ia32.o.before /tmp/sys_ia32.o.after > -rw-rw-r-- 1 acme acme 185240 2008-02-06 19:19 /tmp/sys_ia32.o.after > -rw-rw-r-- 1 acme acme 248328 2008-02-06 19:00 /tmp/sys_ia32.o.before > > Almost 64KB only on this object file! > > There were no other side effects from this change: > > [acme@doppio net-2.6]$ objcopy -j "text" /tmp/sys_ia32.o.before /tmp/text.before > [acme@doppio net-2.6]$ objcopy -j "text" /tmp/sys_ia32.o.after /tmp/text.after > [acme@doppio net-2.6]$ md5sum /tmp/text.before /tmp/text.after > b7ac9b17942add68494e698e4f965d36 /tmp/text.before > b7ac9b17942add68494e698e4f965d36 /tmp/text.after > > One of the complaints about using tools such as systemtap is > that one has to install the huge kernel-debuginfo package: > > [acme@doppio net-2.6]$ rpm -q --qf "%{size}\n" kernel-rt-debuginfo > 471737710 > 543867594 > [acme@doppio net-2.6]$ > > So I'll try to improve automation to find more of these cases. That'd be grat. > Here goes the first patch, regards. Applied. Thanks, tglx -- 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/