This is the mail archive of the
gdb-patches@sourceware.org
mailing list for the GDB project.
Re: [PATCH] GDB/testsuite: Bump up `match_max'
- From: Doug Evans <dje at google dot com>
- To: Joel Brobecker <brobecker at adacore dot com>
- Cc: Tom Tromey <tromey at redhat dot com>, "Maciej W. Rozycki" <macro at codesourcery dot com>, gdb-patches <gdb-patches at sourceware dot org>
- Date: Mon, 19 May 2014 14:22:13 -0700
- Subject: Re: [PATCH] GDB/testsuite: Bump up `match_max'
- Authentication-results: sourceware.org; auth=none
- References: <alpine dot DEB dot 1 dot 10 dot 1405172136000 dot 12061 at tp dot orcam dot me dot uk> <87bnutzwbj dot fsf at fleche dot redhat dot com> <20140519142324 dot GB22822 at adacore dot com> <20140519143702 dot GC22822 at adacore dot com>
On Mon, May 19, 2014 at 7:37 AM, Joel Brobecker <brobecker@adacore.com> wrote:
>> > I wonder whether you timed the test suite?
>> > The expect man page says:
>> >
>> > This may be changed with the function match_max. (Note that excessively
>> > large values can slow down the pattern matcher.)
>> >
>> > If it is notably slower then it would be better to rewrite the macro
>> > tests to avoid this need.
>>
>> Funny you would say that! I was reviewing the patch, and decided to
>> do exactly that. Ran into trouble (fresh install), but almost there...
>
> Here are the results. As I hoped, it doesn't seem to introduce
> any noticeable difference (at -j16 on an 8-thread machine).
>
> Before: 1093.79s user 153.20s system 589% cpu 3:31.68 total
> After: 1097.58s user 155.08s system 589% cpu 3:32.39 total
Hi.
fwiw, I did several runs of before/after with the testsuite running
serially and didn't find any statistical difference.
All runs were in the range 14:07s to 14:25s elapsed, and sometimes
with-patch was faster.
Not unexpected I guess - most of the time what's actually in the
buffer is pretty small, much less than the buffer size, so other
factors would (generally) have more of an influence on run time.