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From: Paul H. Hargrove (PHHargrove_at_[hidden])
Date: 2007-06-11 14:49:19


If Jeff has the resources to run threaded tests against 1.2, *and* to
examine the results, then it might be valuable to have a summary the
known threading issues in 1.2 written down somewhere for the benefit of
those who don't chase the trunk.

-Paul

Graham, Richard L. wrote:
> I would second this - thread safety should be a 1.3 item, unless someone has a lot of spare time.
>
> Rich
>
> -----Original Message-----
> From: devel-bounces_at_[hidden] <devel-bounces_at_[hidden]>
> To: Open MPI Developers <devel_at_[hidden]>
> Sent: Mon Jun 11 10:44:33 2007
> Subject: Re: [OMPI devel] threaded builds
>
>
> On Jun 11, 2007, at 8:25 AM, Jeff Squyres wrote:
>
>
>> I leave it to the thread subgroup to decide... Should we discuss on
>> the call tomorrow?
>>
>> I don't have a strong opinion; I was just testing both because it was
>> easy to do so. If we want to concentrate on the trunk, I can adjust
>> my MTT setup.
>>
>>
>
> I think trying to worry about 1.2 would just be a time sink. We know
> that there are architectural issues with threads in some parts of the
> code. I don't see us re-architecting 1.2 in this regard.
> Seems we should only focus on the trunk.
>
>
> - Galen
>
>
>
>> On Jun 11, 2007, at 10:17 AM, Brian Barrett wrote:
>>
>>
>>> Yes, this is a known issue. I don't know -- are we trying to make
>>> threads work on the 1.2 branch, or just the trunk? I had thought
>>> just the trunk?
>>>
>>> Brian
>>>
>>>
>>> On Jun 11, 2007, at 8:13 AM, Tim Prins wrote:
>>>
>>>
>>>> I had similar problems on the trunk, which was fixed by Brian with
>>>> r14877.
>>>>
>>>> Perhaps 1.2 needs something similar?
>>>>
>>>> Tim
>>>>
>>>> On Monday 11 June 2007 10:08:15 am Jeff Squyres wrote:
>>>>
>>>>> Per the teleconf last week, I have started to revamp the Cisco MTT
>>>>> infrastructure to do simplistic thread testing. Specifically, I'm
>>>>> building the OMPI trunk and v1.2 branches with "--with-threads --
>>>>> enable-mpi-threads".
>>>>>
>>>>> I haven't switched this into my production MTT setup yet, but in
>>>>> the
>>>>> first trial runs, I'm noticing a segv in the test/threads/
>>>>> opal_condition program.
>>>>>
>>>>> It seems that in the thr1 test on the v1.2 branch, when it calls
>>>>> opal_progress() underneath the condition variable wait, at some
>>>>> point
>>>>> in there current_base is getting to be NULL. Hence, the following
>>>>> segv's because the passed in value of "base" is NULL (event.c):
>>>>>
>>>>> int
>>>>> opal_event_base_loop(struct event_base *base, int flags)
>>>>> {
>>>>> const struct opal_eventop *evsel = base->evsel;
>>>>> ...
>>>>>
>>>>> Here's the full call stack:
>>>>>
>>>>> #0 0x0000002a955a020e in opal_event_base_loop (base=0x0, flags=5)
>>>>> at event.c:520
>>>>> #1 0x0000002a955a01f9 in opal_event_loop (flags=5) at event.c:514
>>>>> #2 0x0000002a95599111 in opal_progress () at runtime/
>>>>> opal_progress.c:
>>>>> 259
>>>>> #3 0x00000000004012c8 in opal_condition_wait (c=0x5025a0,
>>>>> m=0x502600)
>>>>> at ../../opal/threads/condition.h:81
>>>>> #4 0x0000000000401146 in thr1_run (obj=0x503110) at
>>>>> opal_condition.c:46
>>>>> #5 0x00000036e290610a in start_thread () from /lib64/tls/
>>>>> libpthread.so.0
>>>>> #6 0x00000036e1ec68c3 in clone () from /lib64/tls/libc.so.6
>>>>> #7 0x0000000000000000 in ?? ()
>>>>>
>>>>> This test seems to work fine on the trunk (at least, it didn't segv
>>>>> in my small number of trail runs).
>>>>>
>>>>> Is this a known problem in the 1.2 branch? Should I skip the
>>>>> thread
>>>>> testing on the 1.2 branch and concentrate on the trunk?
>>>>>
>>>> _______________________________________________
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>>>>
>>> _______________________________________________
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>>>
>> --
>> Jeff Squyres
>> Cisco Systems
>>
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>
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-- 
Paul H. Hargrove                          PHHargrove_at_[hidden]
Future Technologies Group                 
HPC Research Department                   Tel: +1-510-495-2352
Lawrence Berkeley National Laboratory     Fax: +1-510-486-6900