Halim, Thanks for creating the ticket. This likely will not be fixed in time for mpich 3.1.2, but I hope to get time to investigate this problem in the 3.1.3 timerframe .... whenever that is scheduled. Michael Blocksome Parallel Environment MPI Middleware Team Lead, TCEM POWER, x86, and Blue Gene HPC Messaging [email protected] From: Halim <[email protected]> To: [email protected] Date: 07/17/2014 02:54 PM Subject: Re: [mpich-discuss] Deadlock when using MPICH 3.1.1 and per-object critical sections on BG/Q Sent by: [email protected] Hi Michael, Thanks. I created a ticket (#2132) on trac.mpich.org to track the problem. Regards, --Halim On 2014年06月26日 17:41, Michael Blocksome wrote:

Halim,

This problem sounds similar to another issue we are debugging related to cancel and multiple endpoints in per-object locking mode. I'll try a few things and post status.

Thanks,

Michael Blocksome Parallel Environment MPI Middleware Team Lead, TCEM POWER, x86, and Blue Gene HPC Messaging [email protected]

From: Halim <[email protected]> To: [email protected], Date: 06/26/2014 02:31 PM Subject: [mpich-discuss] Deadlock when using MPICH 3.1.1 and per-object critical sections on BG/Q Sent by: [email protected]

Hi,

I have a specific issue that arises with MPICH (I use 3.1.1 built with gcc) + MPI_THREAD_MULTIPLE + per-object critical sections on BG/Q.

A deadlock happens in the attached hybrid MPI+OpenMP example code with 2 processes and more than one thread per process.

Debugging shows that one process is stuck in MPI_Allreduce while the other is blocked in MPI_Finalize.

A similar communication pattern happens in my application, but in this case both processes are stuck in MPI_Allreduce.

Note that the problem disappears when removing MPI_Allreduce, or avoiding request cancellation (cancel+wait+test_cancelled). Both Allreduce and cancellation operations can be avoided in this test while ensuring a correct result. But in my application, both operations are necessary.

In addition, using a global critical section (default) results in a correct execution.

My configure line is as follows:

./configure --prefix=/home/aamer/usr --host=powerpc64-bgq-linux --with-device=pamid --with-file-system=gpfs:BGQ --with-file-system=bg+bglockless --with-atomic-primitives --enable-handle-allocation=tls --enable-refcount=lock-free -disable-predefined-refcount --disable-error-checking --without-timing --without-mpit-pvars --enable-fast=O3,ndebug --enable-thread-cs=per-object

I appreciate any advice to solve this issue?

Regards, --Halim [attachment "allred_cancel.c" deleted by Michael Blocksome/Rochester/IBM] _______________________________________________ discuss mailing list [email protected] To manage subscription options or unsubscribe: https://lists.mpich.org/mailman/listinfo/discuss

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