diff options
Diffstat (limited to 'kernel/kernel/locking/mcs_spinlock.h')
| -rw-r--r-- | kernel/kernel/locking/mcs_spinlock.h | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/kernel/kernel/locking/mcs_spinlock.h b/kernel/kernel/locking/mcs_spinlock.h index 5b9102a47..c835270f0 100644 --- a/kernel/kernel/locking/mcs_spinlock.h +++ b/kernel/kernel/locking/mcs_spinlock.h @@ -67,7 +67,13 @@ void mcs_spin_lock(struct mcs_spinlock **lock, struct mcs_spinlock *node) node->locked = 0; node->next = NULL; - prev = xchg_acquire(lock, node); + /* + * We rely on the full barrier with global transitivity implied by the + * below xchg() to order the initialization stores above against any + * observation of @node. And to provide the ACQUIRE ordering associated + * with a LOCK primitive. + */ + prev = xchg(lock, node); if (likely(prev == NULL)) { /* * Lock acquired, don't need to set node->locked to 1. Threads |