From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 23631 invoked by alias); 1 Jul 2008 12:13:33 -0000 Received: (qmail 23618 invoked by uid 22791); 1 Jul 2008 12:13:32 -0000 X-Spam-Status: No, hits=-1.9 required=5.0 tests=AWL,BAYES_00,SPF_HELO_PASS,SPF_SOFTFAIL X-Spam-Check-By: sourceware.org Received: from www.church-of-our-saviour.org (HELO thunker.thunk.org) (69.25.196.31) by sourceware.org (qpsmtpd/0.31) with ESMTP; Tue, 01 Jul 2008 12:13:15 +0000 Received: from root (helo=closure.thunk.org) by thunker.thunk.org with local-esmtp (Exim 4.50 #1 (Debian)) id 1KDeix-00085r-U6; Tue, 01 Jul 2008 08:12:44 -0400 Received: from tytso by closure.thunk.org with local (Exim 4.69) (envelope-from ) id 1KDeix-0007Fj-67; Tue, 01 Jul 2008 08:12:43 -0400 Date: Tue, 01 Jul 2008 12:13:00 -0000 From: Theodore Tso To: Sam Ravnborg Cc: Roland McGrath , ksummit-2008-discuss@lists.linux-foundation.org, systemtap@sources.redhat.com Bcc: tytso@mit.edu Subject: Re: [Ksummit-2008-discuss] DTrace Message-ID: <20080701121243.GE22717@mit.edu> References: <20080630010423.GA7068@redhat.com> <20080630181959.GA7988@mit.edu> <20080630192533.GE21660@redhat.com> <20080630201031.GF7988@mit.edu> <20080630204219.GA6631@redhat.com> <20080701024140.GB28143@mit.edu> <20080701070746.C6DAD15420E@magilla.localdomain> <20080701101507.GB22717@mit.edu> <20080701110517.GB6914@uranus.ravnborg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080701110517.GB6914@uranus.ravnborg.org> User-Agent: Mutt/1.5.17+20080114 (2008-01-14) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: tytso@mit.edu X-SA-Exim-Scanned: No (on thunker.thunk.org); SAEximRunCond expanded to false Mailing-List: contact systemtap-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: systemtap-owner@sourceware.org X-SW-Source: 2008-q3/txt/msg00011.txt.bz2 On Tue, Jul 01, 2008 at 01:05:17PM +0200, Sam Ravnborg wrote: > On Tue, Jul 01, 2008 at 06:15:07AM -0400, Theodore Tso wrote: > > > > I've pulled apart RHEL's rpm macro magic before, and it's not a > > pleasant wading through all of the files; maybe we can teach the > > native kernel build infrastructure how to create debuginfo files so > > that each distribution doesn't have to re-invent the wheel from > > scratch, but rather can reuse common infrastructure in Kbuild.... > > What is needed to create debuginfo files? > Seems like a simple thing to integrate in kbuild > if this is per file or per module. Well, the simple/stupdiest thing we can do is simply have an alternate target which installs the modules in $(INSTALL_MOD_PATH)/usr/lib/debug/$(KERNELRELEASE) ... while ignoring the INSTALL_MOD_STRIP option. You may recall that that I submitted the patch to add INSTALL_MOD_STRIP (commit ac031f26e); this was from an earlier attempt of mine to use kdump/systemtap. RHEL's rpm macro magic does some additional objcopy's which I'll have to try to ease out to strip out the text segments and only leave the debug information in debuginfo files, which helps slim them down a little. > > If it is for the kernel as a whole things gets a bit more complex. > It would be nice to do this for the base kernel as well (a vmlinux with strip --strip-debug applied takes only 6 megs in /boot on my system, but a vmlinux with full debugging information takes 66 megs; so moving the unstripped vmlinux out of /boot to /usr/lib/debug would be quite helpful for people who created their /boot partition not allowing for the rather dramatic increase in size needed for kernels built with debugging information.) - Ted