This is an automated email from the git hooks/post-receive script. It was generated because a ref change was pushed to the repository containing the project "MPICH primary repository". The branch, master has been updated via 4b35902a9704bb6ebdc1767d73d36443ca37fe73 (commit) from 1f532907778162971e6bf51b754b68c95861cd66 (commit) Those revisions listed above that are new to this repository have not appeared on any other notification email; so we list those revisions in full, below. - Log ----------------------------------------------------------------- http://git.mpich.org/mpich.git/commitdiff/4b35902a9704bb6ebdc1767d73d36443ca... commit 4b35902a9704bb6ebdc1767d73d36443ca37fe73 Author: Su Huang <[email protected]> Date: Wed Mar 19 04:27:47 2014 -0400 MPICH test case linked_list_lockall hang in MPI_Win_flush The scenario of the hang is described as follows: Assuming the job runs with 4 tasks, task 0 is in a loop of processing the following RMA operations to fetch the displacement, the loop ends if the displacement is being updated. MPI_Win_get_accumulate( target rank is task 0) MPI_Win_flush(task 0) task 1 and 3 hang in MPI_Win_flush() waiting for a call to MPI_Win_compare_and_swap() to complete. The target rank for this operation is task 0. task 2 hangs in MPI_Win_flush() waiting for a call to MPI_Accumulate() to complete. The target rank for this operation is task 0 as well. Task 0 is busy making MPI_Win_get_accumulate() and MPI_Win_flush() calls to see if the displacement is being updated, the target rank of the operation is task 0 itself which means the operation is local and can be completed without a need of making a PAMI dispatcher call. Meanwhile, the other three tasks issue RMA operations to the target task 0 and wait for the completion of the operations. Because task 0 is in a loop of making local operations, no PAMI dispatcher is called, no progress made for any remote operations which is the root cause of the hang. The fix for the problem is to add a call to PAMI dispatcher in MPI_Win_flush(), the call is made prior to the check of the condition. Current code checks the condition first, if the condition is satisfied, then no PAMI dispatcher is called. The following statement in MPI_Win_flush() MPID_PROGRESS_WAIT_WHILE(sync->total != sync->complete) will be replaced by MPID_PROGRESS_WAIT_DO_WHILE(sync->total != sync->complete) (ibm) D196445 Signed-off-by: Michael Blocksome <[email protected]> diff --git a/src/mpid/pamid/src/onesided/mpid_win_flush.c b/src/mpid/pamid/src/onesided/mpid_win_flush.c index c2e7e29..310d059 100644 --- a/src/mpid/pamid/src/onesided/mpid_win_flush.c +++ b/src/mpid/pamid/src/onesided/mpid_win_flush.c @@ -53,7 +53,7 @@ MPID_Win_flush(int rank, return mpi_errno, "**rmasync"); } sync = &win->mpid.sync; - MPID_PROGRESS_WAIT_WHILE(sync->total != sync->complete); + MPID_PROGRESS_WAIT_DO_WHILE(sync->total != sync->complete); sync->total = 0; sync->started = 0; sync->complete = 0; ----------------------------------------------------------------------- Summary of changes: src/mpid/pamid/src/onesided/mpid_win_flush.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) hooks/post-receive -- MPICH primary repository