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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-05-09 07:47:14 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-05-09 07:58:48 -0300
commita5cdf7364020a61375af3c8aa23e09181f5c2c6c (patch)
tree6a7aacf0e34c69ae57200ba59eafda251b3e0e80 /kernel/locking
parent394569928e2f17dff4ae367ac700048138e318c7 (diff)
Linux-libre 4.5.3-gnupck-4.5.3-gnu
Diffstat (limited to 'kernel/locking')
-rw-r--r--kernel/locking/mcs_spinlock.h8
1 files changed, 7 insertions, 1 deletions
diff --git a/kernel/locking/mcs_spinlock.h b/kernel/locking/mcs_spinlock.h
index 5b9102a47..c835270f0 100644
--- a/kernel/locking/mcs_spinlock.h
+++ b/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