Replace this pattern in active_fence_cb():
cmpxchg(*ptr, old, new) == old
... with the simpler and faster:
try_cmpxchg(*ptr, &old, new)
The x86 CMPXCHG instruction returns success in the ZF flag,
so this change saves a compare after the CMPXCHG.
Signed-off-by: Uros Bizjak <[email protected]>
Cc: Jani Nikula <[email protected]>
Cc: Joonas Lahtinen <[email protected]>
Cc: Rodrigo Vivi <[email protected]>
Cc: Tvrtko Ursulin <[email protected]>
Cc: David Airlie <[email protected]>
Cc: Simona Vetter <[email protected]>
---
drivers/gpu/drm/i915/i915_active.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/i915_active.c
b/drivers/gpu/drm/i915/i915_active.c
index 5ec293011d99..35319228bc51 100644
--- a/drivers/gpu/drm/i915/i915_active.c
+++ b/drivers/gpu/drm/i915/i915_active.c
@@ -212,7 +212,7 @@ active_fence_cb(struct dma_fence *fence, struct
dma_fence_cb *cb)
struct i915_active_fence *active =
container_of(cb, typeof(*active), cb);
- return cmpxchg(__active_fence_slot(active), fence, NULL) == fence;
+ return try_cmpxchg(__active_fence_slot(active), &fence, NULL);
}
static void
--
2.46.2
