[petsc-dev] Is mpich/master:a8a2b30fd21 tested with Petsc?

[Eric Chamberland]

Hi,

this morning, mpich/master with PETSc is 100% working again for us.

Thanks to both commits:

https://github.com/pmodels/mpich/commit/c597c8d79deea220a42751fda0f01ce70764c260

https://github.com/pmodels/mpich/commit/8edabc7373b82dd660019e53d246131765819294

and thanks to everybody who helped:

Satish
Min
Wesley
Ken
Rob
Jed

:)

Eric

On 17/04/18 04:58 PM, Min Si wrote:
> Hi all,
> 
> Thanks for narrowing down the problem. I checked the MPICH code and 
> believe this is a bug in MPICH. I just created a PR to fix it:
> https://github.com/pmodels/mpich/pull/3097
> 
> It should be merged into MPICH master branch soon.
> 
> Thanks,
> Min
> 
> On 2018/04/17 14:10, Eric Chamberland wrote:
>> Hi,
>>
>> are we talking about the "tag" passed to MPI_Isend for example?
>>
>> but does that mean there is something to change for any MPI call which 
>> involves tags usage or is it only a PETSc "bad" tag usage?
>>
>> thanks Satish for your finding!
>>
>> Eric
>>
>> On 16/04/18 11:31 PM, Satish Balay wrote:
>>> On Tue, 13 Mar 2018, Eric Chamberland wrote:
>>>
>>>> Hi,
>>>>
>>>> each night we are testing mpich/master with our petsc-based code.  I 
>>>> don't
>>>> know if PETSc team is doing the same thing with mpich/master? (Maybe 
>>>> it is a
>>>> good idea?)
>>>>
>>>> Everything was fine (except the issue
>>>> https://github.com/pmodels/mpich/issues/2892) up to commit 
>>>> 7b8d64debd, but
>>>> since commit mpich:a8a2b30fd21), I have a segfault on a any parallel 
>>>> nightly
>>>> test.
>>>
>>> I attempted a bisect of the above range of commits - and narrowed 
>>> down to:
>>>
>>>>>>>>>>
>>> db11d4c4a70e39a28be88ed32f00542301699e08 is the first bad commit
>>> <<<<<<<
>>>>>>>>>>>
>>> balay at asterix /home/balay/soft/build/mpich ((db11d4c4a...)|BISECTING)
>>> $ git show db11d4c4a70e39a28be88ed32f00542301699e08
>>> commit db11d4c4a70e39a28be88ed32f00542301699e08 (HEAD, refs/bisect/bad)
>>> Author: Ken Raffenetti <raffenet at mcs.anl.gov>
>>> Date:   Thu Feb 15 11:37:59 2018 -0600
>>>
>>>      init: Fix tag upper limit initialization
>>>           The starting point for this value is equivalent to the 
>>> usable tag bits
>>>      macro. This value should be set before device initialization,
>>>      otherwise devices will assume they have more bits than are actually
>>>      available.
>>>           Signed-off-by: Wesley Bland <wesley.bland at intel.com>
>>>
>>> diff --git a/src/mpi/init/initthread.c b/src/mpi/init/initthread.c
>>> index cbc41f4d5..b31ae2f07 100644
>>> --- a/src/mpi/init/initthread.c
>>> +++ b/src/mpi/init/initthread.c
>>> @@ -403,7 +403,7 @@ int MPIR_Init_thread(int *argc, char ***argv, int 
>>> required, int *provided)
>>>       MPIR_Process.attrs.host = MPI_PROC_NULL;
>>>       MPIR_Process.attrs.io = MPI_PROC_NULL;
>>>       MPIR_Process.attrs.lastusedcode = MPI_ERR_LASTCODE;
>>> -    MPIR_Process.attrs.tag_ub = 0;
>>> +    MPIR_Process.attrs.tag_ub = MPIR_TAG_USABLE_BITS;
>>>       MPIR_Process.attrs.universe = MPIR_UNIVERSE_SIZE_NOT_SET;
>>>       MPIR_Process.attrs.wtime_is_global = 0;
>>>   @@ -531,13 +531,6 @@ int MPIR_Init_thread(int *argc, char ***argv, 
>>> int required, int *provided)
>>>       MPIR_Assert(((unsigned) MPIR_Process.
>>>                    attrs.tag_ub & ((unsigned) 
>>> MPIR_Process.attrs.tag_ub + 1)) == 0);
>>>   -    /* Set aside tag space for tagged collectives and failure 
>>> notification */
>>> -#ifdef HAVE_TAG_ERROR_BITS
>>> -    MPIR_Process.attrs.tag_ub >>= 3;
>>> -#else
>>> -    MPIR_Process.attrs.tag_ub >>= 1;
>>> -#endif
>>> -
>>>       /* Assert: tag_ub is at least the minimum asked for in the MPI 
>>> spec */
>>>       MPIR_Assert(MPIR_Process.attrs.tag_ub >= 32767);
>>> <<<<<<<<<<<<<<<<<
>>>
>>> Reverthing this patch gets mpich-3.3b2 working with petsc
>>>
>>> Satish
>>>