Re: [pushed] Improve gdb.threads/attach-many-short-lived-threads.exp timeout handling

[Pedro Alves <palves@redhat.com>]

On 02/09/2015 09:55 PM, Doug Evans wrote:
> On Fri, Feb 6, 2015 at 4:25 AM, Pedro Alves <palves@redhat.com> wrote:
>> The buildbot shows that this test is still racy, and occasionally
>> fails with time outs on some machines.  I'd like to get major issues
>> with load out of the way.
> 
> Thanks for fixing this.
> 
> btw, how often do you run the testsuite in parallel?
> I see such load related issues all the time that way.

Yeah, I run the testsuite in parallel all the time, with
-j8, on an i7-2620M (2 cores / 4 threads).

The attach-many-short-lived-threads.exp never fails
for me though.  I've now got access to Sergio's build slave,
the one that generates the buildbot test results that show the
racy failures, and when I run that test manually, in a loop, I
never see it fail.  OTOH, through build bot the test fails
very often...  This was last thing last Friday, and I
haven't managed to get back to it yet.  The test seems to
expose more bugs, but the build bot also shows it FAILing in
a very odd way sometimes, like failing to attach the very first
time.

> [e.g., checkpoint.exp, gdb-sigterm.exp, et.al.]

Yeah, checkpoint.exp forks a ton of processes, and sometimes I'll
hit the "ulimit -u (max user processes)" limit when running in parallel.
I bump that "ulimit -u 10000" in the shell that I run tests on,
and then it never fails.

The gdb-sigterm.exp one should be fixed, I hope, since:
  https://sourceware.org/ml/gdb-patches/2015-02/msg00151.html

Thanks,
Pedro Alves