maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

Add missing memory barrier for queuing locks 

Otherwise I see hangs in the omp_single_copyprivate test when
compiling in release mode. With the debug assertions, I get a
failure `head > 0 && tail > 0`.

Differential Revision: https://reviews.llvm.org/D40722

llvm-svn: 320150
This commit is contained in:
Jonas Hahnfeld 2017-12-08 15:07:02 +00:00
parent dfa430f694
commit 86c307821c
2 changed files with 2 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
openmp/runtime/src/kmp_lock.cpp
View File

@ -1456,6 +1456,7 @@ int __kmp_release_queuing_lock(kmp_queuing_lock_t *lck, kmp_int32 gtid) {
} }
dequeued = FALSE; dequeued = FALSE;
} else { } else {
KMP_MB();
tail = *tail_id_p; tail = *tail_id_p;
if (head == tail) { /* only one thread on the queue */ if (head == tail) { /* only one thread on the queue */
#ifdef DEBUG_QUEUING_LOCKS #ifdef DEBUG_QUEUING_LOCKS

2
openmp/runtime/test/worksharing/single/omp_single_copyprivate.c
View File

@ -13,7 +13,7 @@ int test_omp_single_copyprivate()
result = 0; result = 0;
nr_iterations = 0; nr_iterations = 0;
#pragma omp parallel #pragma omp parallel num_threads(4)
{ {
int i; int i;
for (i = 0; i < LOOPCOUNT; i++) for (i = 0; i < LOOPCOUNT; i++)