Make sure opal_start_thread always spawns pthreads [v5.0.x] #9395
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Users of `opal_start_thread` (btl/tcp, ft, smcuda, progress thread) may spawn threads that may block in functions unaware of argobots or qthreads (e.g., libevent or read(3)). If we spawn an argobot or qthread instead of a pthread the thread executing the argobot or qthread (potentially the main thread) blocks, leading to a deadlock situation. Open MPI expects the semantics of a pthread so we should handle all internal threads as such. Signed-off-by: Joseph Schuchart <[email protected]> (cherry picked from commit e3ca132)
hppritcha
approved these changes
Sep 22, 2021
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Users of
opal_start_thread(btl/tcp, ft, smcuda, progress thread)may spawn threads that may block in functions unaware of argobots
or qthreads (e.g., libevent or read(3)). If we spawn an argobot or
qthread instead of a pthread the thread executing the argobot or
qthread (potentially the main thread) blocks, leading to a deadlock
situation. Open MPI expects the semantics of a pthread so
we should handle all internal threads as such.
Backport of #9326 to v5.0.x
Signed-off-by: Joseph Schuchart [email protected]
(cherry picked from commit e3ca132)