On 03.07.2015 01:54, Grigori Goronzy wrote:
We don't need to call the (expensive) radeon_bo_wait, checking the fences via RCU is much faster. The reservation done by radeon_bo_wait does not save us from any race conditions.
Signed-off-by: Grigori Goronzy greg@chown.ath.cx
Patche #1-#3 are Reviewed-by: Christian König christian.koenig@amd.com
Patch #4 is a nice catch, but as Michel already noted needs more thoughts for a complete fix.
Regards, Christian.
drivers/gpu/drm/radeon/radeon_gem.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/radeon/radeon_gem.c b/drivers/gpu/drm/radeon/radeon_gem.c index ac3c131..7199e19 100644 --- a/drivers/gpu/drm/radeon/radeon_gem.c +++ b/drivers/gpu/drm/radeon/radeon_gem.c @@ -428,7 +428,6 @@ int radeon_gem_mmap_ioctl(struct drm_device *dev, void *data, int radeon_gem_busy_ioctl(struct drm_device *dev, void *data, struct drm_file *filp) {
- struct radeon_device *rdev = dev->dev_private; struct drm_radeon_gem_busy *args = data; struct drm_gem_object *gobj; struct radeon_bo *robj;
@@ -440,10 +439,16 @@ int radeon_gem_busy_ioctl(struct drm_device *dev, void *data, return -ENOENT; } robj = gem_to_radeon_bo(gobj);
- r = radeon_bo_wait(robj, &cur_placement, true);
- r = reservation_object_test_signaled_rcu(robj->tbo.resv, true);
- if (r == 0)
r = -EBUSY;- else
r = 0;- cur_placement = ACCESS_ONCE(robj->tbo.mem.mem_type); args->domain = radeon_mem_type_to_domain(cur_placement); drm_gem_object_unreference_unlocked(gobj);
- r = radeon_gem_handle_lockup(rdev, r); return r; }