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authorJ. Bruce Fields <bfields@redhat.com>2012-10-09 22:35:22 (GMT)
committerJ. Bruce Fields <bfields@redhat.com>2012-10-09 22:35:22 (GMT)
commitf474af7051212b4efc8267583fad9c4ebf33ccff (patch)
tree1aa46ebc8065a341f247c2a2d9af2f624ad1d4f8 /include/asm-generic/mutex-xchg.h
parent0d22f68f02c10d5d10ec5712917e5828b001a822 (diff)
parente3dd9a52cb5552c46c2a4ca7ccdfb4dab5c72457 (diff)
downloadlinux-f474af7051212b4efc8267583fad9c4ebf33ccff.tar.xz
nfs: disintegrate UAPI for nfs
This is to complete part of the Userspace API (UAPI) disintegration for which the preparatory patches were pulled recently. After these patches, userspace headers will be segregated into: include/uapi/linux/.../foo.h for the userspace interface stuff, and: include/linux/.../foo.h for the strictly kernel internal stuff. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Diffstat (limited to 'include/asm-generic/mutex-xchg.h')
-rw-r--r--include/asm-generic/mutex-xchg.h11
1 files changed, 9 insertions, 2 deletions
diff --git a/include/asm-generic/mutex-xchg.h b/include/asm-generic/mutex-xchg.h
index 580a6d3..c04e0db 100644
--- a/include/asm-generic/mutex-xchg.h
+++ b/include/asm-generic/mutex-xchg.h
@@ -26,7 +26,13 @@ static inline void
__mutex_fastpath_lock(atomic_t *count, void (*fail_fn)(atomic_t *))
{
if (unlikely(atomic_xchg(count, 0) != 1))
- fail_fn(count);
+ /*
+ * We failed to acquire the lock, so mark it contended
+ * to ensure that any waiting tasks are woken up by the
+ * unlock slow path.
+ */
+ if (likely(atomic_xchg(count, -1) != 1))
+ fail_fn(count);
}
/**
@@ -43,7 +49,8 @@ static inline int
__mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *))
{
if (unlikely(atomic_xchg(count, 0) != 1))
- return fail_fn(count);
+ if (likely(atomic_xchg(count, -1) != 1))
+ return fail_fn(count);
return 0;
}