Op 07-04-15 om 15:37 schreef Daniel Vetter: > On Tue, Apr 07, 2015 at 11:32:02AM +0200, Maarten Lankhorst wrote: >> Signed-off-by: Maarten Lankhorst <[email protected]> >> --- >> diff --git a/drivers/gpu/drm/i915/i915_drv.h >> b/drivers/gpu/drm/i915/i915_drv.h >> index b13c5526a73b..7aaf8eddf19c 100644 >> --- a/drivers/gpu/drm/i915/i915_drv.h >> +++ b/drivers/gpu/drm/i915/i915_drv.h >> @@ -2146,14 +2146,14 @@ i915_gem_request_unreference(struct >> drm_i915_gem_request *req) >> static inline void >> i915_gem_request_unreference__unlocked(struct drm_i915_gem_request *req) >> { >> - if (req && !atomic_add_unless(&req->ref.refcount, -1, 1)) { >> - struct drm_device *dev = req->ring->dev; >> + struct drm_device *dev; >> + >> + if (!req) >> + return; >> >> - mutex_lock(&dev->struct_mutex); >> - if (likely(atomic_dec_and_test(&req->ref.refcount))) >> - i915_gem_request_free(&req->ref); >> + dev = req->ring->dev; >> + if (kref_put_mutex(&req->ref, i915_gem_request_free, >> &dev->struct_mutex)) >> mutex_unlock(&dev->struct_mutex); > We don't need this conditional unlock here since that's only possible if > you have a weak reference somewhere (i.e. using kref_get_unless_zero). If > the object only has strong references and you're dropping the last one it > can't magically get resurrected somehow. Because we use the same put call for kref_put and kref_put_mutex we do need to unlock struct_mutex here, kref_put_mutex doesn't release the mutex if true, so either the release call needs to do it or the callee.
> And drm_gem_object_unreference_unlocked wants the same patch I think. Indeed it does, but with slightly more lockdep annotation! _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx
