Jit file locking is probably buggy

[Martin Sandve Alnæs]

This could be either in ffc jit or in instant. When running dolfin tests with mpirun, we seem to get deadlocks with all processes using 100% cpu forever on some tests. Making sure the tests are run in serial first seems to solve the problem. I may be wrong and the problem may be somewhere else. But the horrible implementation of file locking that we have is a likely culprit.

[Jan Blechta]

Are you referring to buildbot failures? They happen randomly on precise-i386, mpich and trusty-amd64-py3. The first two are timeouts, deadlocks or segfaults but I wouldn't bother trying fixing it with such an old MPI releases. Py3 buildbot tends to get into infinite recursion (on different places in plot demo) and stack overflow, http://fenicsproject.org:8010/builders/dolfin-master-full-trusty-amd64-py3/builds/665/steps/make%20run_regressiontests/logs/demo.log

[Martin Sandve Alnæs]

Yes, and I think blaming the jit file locking is incorrect here. Johannes pinned the precise-i386 failures down to a small mesh.xml that fails to get partitioned correctly, similar to a previous issue but in a different place:

https://bitbucket.org/fenics-project/dolfin/issue/476/not-all-processes-exit-when-creation-of

[Jan Blechta]

Ok. On mpich buildbot we could blame 2 years old MPICH release but what about Py3 buildbot? Can you test with Py3 locally, Martin?

[Martin Sandve Alnæs]

Removing milestone: 1.6 (automated comment)