[petsc-dev] Possible bugs when using TS with ViennaCL

[Karl Rupp]

Hey,

>> For the sake of completeness of this thread:
>>
>> Mani's build included
>> --with-threadcomm --with-pthreadclasses --with-openmp
>> which seems the be the cause of the problem. Without these flags,  the
>> problem disappears and results are correct. If I remember correctly,
>> this is a more fundamental problem in threadcomm rather than specific to
>> the ViennaCL bindings, yet we clearly need to fix it.
>
> [repost from petsc-maint]
>
> Evidently threads are a liability right now.  Do you know what caused
> this behavior so we can avoid it in the future?

Unfortunately I don't know what exactly is causing the problem. My best 
guess is that one of the sys-calls inside threadcomm is in conflict with 
the internals of the OpenCL runtime. I'll see whether I can reproduce 
this on my machine, then I can incrementally disable parts of threadcomm 
until I found the cause.

Best regards,
Karli