[mvapich-discuss] Segmentation fault at some MPI functions after MPI_Put

[khaled hamidouche]

Dear, Akihiro,

There seems to be something missing in your setup, as we are not able to
reproduce the segfault locally. As I mentioned your test passes locally.
Further using the Flush we see expected numbers even with IPC=1 (Please see
below). Note that OMB gives the possibility to test all
synchronization/window creation configuration you want to evaluate.

Thanks

../install/bin/mpirun_rsh -np 2 ivy1 ivy1 MV2_USE_CUDA=1 MV2_CUDA_IPC=1
MV2_USE_GPUDIRECT_GDRCOPY=0 ./osu_put_latency -w create -s flush D D

# OSU MPI_Put-CUDA Latency Test

# Window creation: MPI_Win_create

# Synchronization: MPI_Win_flush

# Rank 0 Memory on DEVICE (D) and Rank 1 Memory on DEVICE (D)

# Size            Latency (us)

0                         0.11

1                        14.95

2                        14.99

4                        14.92

8                        14.95

16                       14.92

32                       14.89

64                       14.93

128                      14.98

256                      14.91

512                      14.91

1024                     14.99

2048                     15.05

4096                     15.03

8192                     14.96

16384                    14.21

32768                    15.78

65536                    15.58

131072                   15.77

262144                   16.58

524288                   18.74

1048576                  27.03

2097152                  38.37

4194304                  59.76


On Thu, Nov 5, 2015 at 1:14 AM, Akihiro Tabuchi <
tabuchi at hpcs.cs.tsukuba.ac.jp> wrote:

> Dear Khaled,
>
> Thank you for your correspondence.
>
> I inserted a MPI_Win_flush before the MPI_Win_unlock but the program's
> behavior was not changed.
> The segmentation fault occured at the same MPI_Win_free.
>
> Best regards,
> Akihiro Tabuchi
>
>
> On 2015年11月05日 04:11, khaled hamidouche wrote:
>
>> Dear Akihiro,
>>
>> There seems to be some interaction between IPC and MPI_Put, we are
>> taking a look at this and get back to you.
>> But in meantime, can you please  try to use Flush synchronization before
>> the unlock. This should help in fixing the behavior you are seeing.
>>
>> Thanks
>>
>>
>
> --
> Akihiro Tabuchi
> tabuchi at hpcs.cs.tsukuba.ac.jp
>



-- 
 K.H
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