This is the mail archive of the
gdb@sourceware.org
mailing list for the GDB project.
Re: [GDB 7.6/GCC 4.8.0] Slowdown in GDB macro processing for cores?
- From: Doug Evans <dje at google dot com>
- To: psmith at gnu dot org
- Cc: Tom Tromey <tromey at redhat dot com>, Pedro Alves <palves at redhat dot com>, gdb <gdb at sourceware dot org>
- Date: Tue, 28 May 2013 10:40:30 -0700
- Subject: Re: [GDB 7.6/GCC 4.8.0] Slowdown in GDB macro processing for cores?
- References: <1368733335 dot 4101 dot 743 dot camel at pdsdesk> <51960329 dot 2010802 at redhat dot com> <1369248335 dot 7209 dot 151 dot camel at homebase> <1369250399 dot 7209 dot 164 dot camel at homebase> <87wqqqg4e2 dot fsf at fleche dot redhat dot com> <1369264444 dot 7209 dot 184 dot camel at homebase> <CADPb22ROm94M3deompzcxeNK=JDk+0gQRu_b97c2wua6TT5Rpg at mail dot gmail dot com> <1369284101 dot 7209 dot 197 dot camel at homebase> <CADPb22TbD-N6Rcw33NpNc2m-rdzWU19Hg8rLG6Thy6JPGU7B1Q at mail dot gmail dot com> <1369762373 dot 3295 dot 20 dot camel at pdsdesk>
On Tue, May 28, 2013 at 10:32 AM, Paul Smith <psmith@gnu.org> wrote:
> On Tue, 2013-05-28 at 10:10 -0700, Doug Evans wrote:
>> And I can't offhand explain why you *only* see the slowdown with a
>> core file and not with a live executable.
>
> Well, just because we haven't found a way to make it happen with live
> debugging doesn't mean it couldn't :-).
Indeed.
>> I wasn't aware of the problems with the 12/11/16 patch you found.
>> I've submitted a minor improvement - IMO the real fix will involve a
>> lot more effort - gdb's symbol handling is obtuse enough that it's
>> easy to introduce performance regressions or even overlook basic
>> performance problems.
>
> I'll try the latest Git to see if it makes a difference.
I'd be curious for before/after data with this patch:
http://sourceware.org/ml/gdb-patches/2013-05/msg00964.html
I doubt it fixes everything, or even a lot of it.
But data is good.