[libfabric-users] CQ permission denied (-EACCES)

[Ezra Kissel]

Great, I will test those changes soon.  Getting some form of 
distributed, threaded test cases in fabtests would be very helpful, I 
think.  I agree the MPI dependence is annoying, needing some general job 
launching and allgather/barrier support instead.  Once I have some free 
cycles again, I might look at integrating some tests myself.

I also have a list of psm issues that have come out of this recent 
debugging... :)

On 02/10/2016 02:30 PM, Jose, Jithin wrote:
> I think the race was because of an unprotected call to get-mr-key. I was able to reproduce it occasionally.
>
> The following patch fixes it, and the test seems to run fine with it; still running in a loop :)
> https://github.com/jithinjosepkl/libfabric/commit/a3a66678cffb376b4cd2bf033ae65fe05df30af0
>
>
> I have also updated the tx_size_left() to check for the CQ availability. All the patches are in https://github.com/jithinjosepkl/libfabric/commits/pr/sockets. Can you give it a try?
>
> Btw, in the application, do you make sure that some other thread is not issuing any TX operations between fi_tx_size_left() and fi_rma* calls? Otherwise, it can still result in -FI_EAGAIN.
>
> - Jithin
>
>
>
>
>
>
> -----Original Message-----
> From: <libfabric-users-bounces at lists.openfabrics.org> on behalf of Ezra Kissel <ezkissel at indiana.edu>
> Date: Wednesday, February 10, 2016 at 8:45 AM
> To: "libfabric-users at lists.openfabrics.org" <libfabric-users at lists.openfabrics.org>
> Subject: [libfabric-users] CQ permission denied (-EACCES)
>
>> Starting a new thread with the issue I was originally trying to debug.
>> We (IU) have libfabric integrated into a task-based runtime system via
>> an intermediate RDMA middleware library and one of our unit tests was
>> often failing with the following error:
>>
>> ALL:ERR: 1 (cq_readerr:53): > local CQ: 13 Permission denied
>> ALL:ERR: 1 (cq_readerr:54): > local CQ: prov_err: Permission denied (-13)
>>
>> Obviously, -EACCES is an appropriate CQ error if the incorrect rkey is
>> specified in an associated RMA op.  I've spent a lot of time debugging
>> this, making sure we are passing the correct rkeys, etc.  I've finally
>> been able to reproduce this issue in a small distributed, threaded test
>> using the sockets provider again, but unfortunately in a
>> non-deterministic way.
>>
>> https://github.com/disprosium8/fi_thread_test/blob/master/fi_rma_thread_mr.c
>>
>> Our unit test that fails causes a lot of memory pressure, and lots of
>> concurrent memory registrations interleaved with RMA ops.  I tried to
>> reproduce this in the above test and it will fail with the CQ error
>> after some number of repeated runs.
>>
>> I get the sense that there's a race condition somewhere, and/or the
>> fi_mr descriptors are getting corrupted.  I can't reproduce the error
>> without the "alloc_thread" running (athreads=0) in the test, and indeed
>> all our other integrated runtime unit tests that have less memory
>> pressure are passing OK.
>>
>> Now that I have a stripped-down test, I can try to more closely trace
>> the root cause but I thought I'd ask for thoughts.
>>
>> - ezra
>> _______________________________________________
>> Libfabric-users mailing list
>> Libfabric-users at lists.openfabrics.org
>> http://lists.openfabrics.org/mailman/listinfo/libfabric-users