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| author | Sergey Vojtovich <svoj@mariadb.org> | 2014-08-29 16:02:46 +0400 |
|---|---|---|
| committer | Sergey Vojtovich <svoj@mariadb.org> | 2014-08-29 16:02:46 +0400 |
| commit | 40497577ffd9f85557b15e08ad913f627b2e9530 (patch) | |
| tree | 75b05e459981227e225f0ebcd21288c3b7cf8e7b /storage/xtradb/include/sync0sync.ic | |
| parent | dd25e7f0ad002c79a8d9768f9d824e79800fb88d (diff) | |
| download | mariadb-git-40497577ffd9f85557b15e08ad913f627b2e9530.tar.gz | |
Backport from 10.0:
MDEV-6450 - MariaDB crash on Power8 when built with advance tool
chain
InnoDB mutex_exit() function calls __sync_test_and_set() to release
the lock. According to manual this function is supposed to create
"acquire" memory barrier whereas in fact we need "release" memory
barrier at mutex_exit().
The problem isn't repeatable with gcc because it creates
"acquire-release" memory barrier for __sync_test_and_set().
ATC creates just "acquire" barrier.
Fixed by creating proper barrier at mutex_exit() by using
__sync_lock_release() instead of __sync_test_and_set().
Diffstat (limited to 'storage/xtradb/include/sync0sync.ic')
| -rw-r--r-- | storage/xtradb/include/sync0sync.ic | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/storage/xtradb/include/sync0sync.ic b/storage/xtradb/include/sync0sync.ic index acc389bfad9..de168964221 100644 --- a/storage/xtradb/include/sync0sync.ic +++ b/storage/xtradb/include/sync0sync.ic @@ -109,10 +109,7 @@ mutex_reset_lock_word( mutex_t* mutex) /*!< in: mutex */ { #if defined(HAVE_ATOMIC_BUILTINS) - /* In theory __sync_lock_release should be used to release the lock. - Unfortunately, it does not work properly alone. The workaround is - that more conservative __sync_lock_test_and_set is used instead. */ - os_atomic_test_and_set_byte(&mutex->lock_word, 0); + os_atomic_lock_release_byte(&mutex->lock_word); #else mutex->lock_word = 0; |