From 22b3e7898ecdf90887a9536fab5b9a6f7a291723 Mon Sep 17 00:00:00 2001 From: Dimitry Andric Date: Wed, 8 May 2024 20:44:28 +0200 Subject: [PATCH] Merge commit 73bb8d9d92f6 from llvm-project (by Jonathan Peyton): [OpenMP] Fix child processes to use affinity_none (#91391) When a child process is forked with OpenMP already initialized, the child process resets its affinity mask and sets proc-bind-var to false so that the entire original affinity mask is used. This patch corrects an issue with the affinity initialization code setting affinity to compact instead of none for this special case of forked children. The test trying to catch this only testing explicit setting of KMP_AFFINITY=none. Add test run for no KMP_AFFINITY setting. Fixes: #91098 This should fix OpenMP processes sometimes getting stuck on a single CPU core. PR: 278845 Reported by: Cassidy B. Larson MFC after: 3 days --- contrib/llvm-project/openmp/runtime/src/kmp_settings.cpp | 2 ++ 1 file changed, 2 insertions(+) diff --git a/contrib/llvm-project/openmp/runtime/src/kmp_settings.cpp b/contrib/llvm-project/openmp/runtime/src/kmp_settings.cpp index ec86ee07472c..58f19ea5b8ab 100644 --- a/contrib/llvm-project/openmp/runtime/src/kmp_settings.cpp +++ b/contrib/llvm-project/openmp/runtime/src/kmp_settings.cpp @@ -6426,6 +6426,8 @@ void __kmp_env_initialize(char const *string) { } if ((__kmp_nested_proc_bind.bind_types[0] != proc_bind_intel) && (__kmp_nested_proc_bind.bind_types[0] != proc_bind_default)) { + if (__kmp_nested_proc_bind.bind_types[0] == proc_bind_false) + __kmp_affinity.type = affinity_none; if (__kmp_affinity.type == affinity_default) { __kmp_affinity.type = affinity_compact; __kmp_affinity.flags.dups = FALSE;