[petsc-users] [petsc-maint] petsc ksp solver hangs

[Matthew Knepley]

What we want to see is the stack trace.

  Thanks

     Matt

On Sat, Sep 28, 2019, 06:33 Michael Wick via petsc-maint <
petsc-maint at mcs.anl.gov> wrote:

> I attached a debugger to my run. The code just hangs without throwing an
> error message, interestingly. I uses 72 processors. I turned on the ksp
> monitor. And I can see it hangs either at the beginning or the end of KSP
> iteration. I also uses valgrind to debug my code on my local machine, which
> does not detect any issue. I uses fgmres + fieldsplit, which is really a
> standard option.
>
> Do you have any suggestions to do?
>
> On Fri, Sep 27, 2019 at 8:17 PM Zhang, Junchao <jczhang at mcs.anl.gov>
> wrote:
>
>> How many MPI ranks did you use? If it is done on your desktop, you can
>> just attach a debugger to a MPI process to see what is going on.
>>
>> --Junchao Zhang
>>
>>
>> On Fri, Sep 27, 2019 at 4:24 PM Michael Wick via petsc-maint <
>> petsc-maint at mcs.anl.gov> wrote:
>>
>>> Hi PETSc:
>>>
>>> I have been experiencing a code stagnation at certain KSP iterations.
>>> This happens rather randomly, which means the code may stop at the middle
>>> of a KSP solve and hangs there.
>>>
>>> I have used valgrind and detect nothing. I just wonder if you have any
>>> suggestions.
>>>
>>> Thanks!!!
>>> M
>>>
>>
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