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-rw-r--r--lib/lockref.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/lib/lockref.c b/lib/lockref.c
index e294ae445c9a..6f9d434c1521 100644
--- a/lib/lockref.c
+++ b/lib/lockref.c
@@ -12,6 +12,14 @@
#endif
/*
+ * Allow architectures to override the default cpu_relax() within CMPXCHG_LOOP.
+ * This is useful for architectures with an expensive cpu_relax().
+ */
+#ifndef arch_mutex_cpu_relax
+# define arch_mutex_cpu_relax() cpu_relax()
+#endif
+
+/*
* Note that the "cmpxchg()" reloads the "old" value for the
* failure case.
*/
@@ -28,7 +36,7 @@
if (likely(old.lock_count == prev.lock_count)) { \
SUCCESS; \
} \
- cpu_relax(); \
+ arch_mutex_cpu_relax(); \
} \
} while (0)
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