Merge commit 5300a6731e98 from llvm-project (by Jonathan Peyton):
[OpenMP] Fix re-locking hang found in issue 86684 (#88539) This was initially reported here (including stacktraces): https://stackoverflow.com/questions/78183545/does-compiling-imagick-with-openmp-enabled-in-freebsd-13-2-cause-sched-yield If `__kmp_register_library_startup()` detects that another instance of the library is present, `__kmp_is_address_mapped()` is eventually called. which uses `kmpc_alloc()` to allocate memory. This function calls `__kmp_entry_thread()` to access the thread-local memory pool, which is a bad idea during initialization. This macro internally calls `__kmp_get_global_thread_id_reg()` which sets the bootstrap lock at the beginning (before calling `__kmp_register_library_startup()`). The fix is to use `KMP_INTERNAL_MALLOC()`/`KMP_INTERNAL_FREE()` instead of `kmpc_malloc()`/`kmpc_free()`. `KMP_INTERNAL_MALLOC` and `KMP_INTERNAL_FREE` do not use any bootstrap locks. They just translate to `malloc()`/`free()` and are meant to be used during library initialization before other library-specific allocators have been initialized. Fixes: #86684
This should fix OpenMP processes sometimes getting locked with 100% CPU
usage, endlessly calling sched_yield(2).
PR: 278845
Reported by: Cassidy B. Larson <cbl@cbl.us>
MFC after: 3 days