It turns that there is an incompatibility between the Cray PMI
library and the default configuration for building Open MPI (master).
To work around this, we now disable use of aprun for direct launch
of Open MPI jobs except under specific conditions.
The problem is that there are now (on master) packages getting
initialized that do not work properly across a fork operation.
As part of a constructor in the Cray PMI library, a fork operation
is done to simplify use of shared memory between the
processes in a job on the same node. This ends up thoroughly
messing up the Open MPI initialization process in the case
that dlopen support is enabled. The initialization process gets
about half-way through when the PMIX framework is opened and
components are loaded, which triggers the Cray PMI constructor
and hence the fork operation.
There are two workarounds for this:
1) configure Open MPI for Cray XE/XC systems using aprun with the
--disable-dlopen option
2) set the PMI_NO_FORK environment variable in the shell in which
the aprun command is run.
Without taking these measures, a Open MPI job will just hang at
job startup in the first attempt to "thread-shift" the PMIx
fence_nb operation. Additional hangs occur at shutdown if this
problem is worked around, again due to the insertion of a fork
operation halfway through the Open MPI initialization procedure.
This commit detects if the conditions that bring out the hang
situation are present, and if so, prints out a message and
aborts the job launch.
Note on systems using slurm, the PMI_NO_FORK environment variable
is set as part of the srun job launch, hence this issue is avoided
on those systems.
Signed-off-by: Howard Pritchard <howardp@lanl.gov>
PR open-mpi/ompi#2432 introduced a regression where configure
and build with --disable-dlopn caused build failure owing
to unresolved alps lli symbols in the libopal-pal shared library.
This commit fixes this problem.
Signed-off-by: Howard Pritchard <howardp@lanl.gov>
Enhance the cray pmix component to set some OMPI internal
env. variables used to set some key/value pairs
on the MPI_INFO_ENV object. This allows more of the
ompi-tests ibm unit tests to pass when using aprun/srun
direct launch and Cray PMI.
Signed-off-by: Howard Pritchard <howardp@lanl.gov>
Still not completely done as we need a better way of tracking the routed module being used down in the OOB - e.g., when a peer drops connection, we want to remove that route from all conduits that (a) use the OOB and (b) are routed, but we don't want to remove it from an OFI conduit.
- replace MAXHOSTNAMELEN with hardcoded 1024.
unlike Linux, Solaris #define MAXHOSTNAMELEN in <netdb.h>,
so use a hard coded value to keep the test simpl
- stdout cannot be assigned on Solaris, so use freopen instead
(back-ported from upstream commit pmix/master@a63f6e53f4)
this is a convenience macro similar to the PMIX_LIST_FOREACH macro,
that can be used to iterate on all the key/value pairs of a pmix_hash_table_t
(back-ported from upstream commit pmix/master@349971c68c)
theses three pmix components use the same class name,
declare it as static so Open MPI can be built with --disable-dlopen
Thanks Limin Gu for the report
pmix_progress_thread_finalize() invokes libevent event_base_free,
so all libevent stuff cannot be used after.
Hence, pmix_client_globals.myserver must be PMIX_DESTRUCT'ed
before invoking pmix_progress_thread_finalize()
pmix1_value_unload() was added a "key" argument which is unused,
and pmix1_value_unload() was sometimes invoked with two arguments instead of three.
since the "key" argument is unused, simply remove it from the
subroutine prototype and calls.
the LT_* macros do overwrite the enable_dlopen variable,
so it must be tested and saved before invoking LT_INIT.
delay the invokation of the LT_* macros and use the
PMIX_ENABLE_DLOPEN_SUPPORT variable to figure out whether
--disable-dlopen was invoked
and fail with a user friendly message if no method is available:
"sec: native cannot validate_cred on this system"
(back-ported from upstream pmix/master@c474a1fc60)
