From 702adba22433c175e8429a47760f35ca16caf1cd Mon Sep 17 00:00:00 2001 From: Thomas Hellstrom Date: Wed, 17 Nov 2010 12:28:29 +0000 Subject: drm/ttm/radeon/nouveau: Kill the bo lock in favour of a bo device fence_lock The bo lock used only to protect the bo sync object members, and since it is a per bo lock, fencing a buffer list will see a lot of locks and unlocks. Replace it with a per-device lock that protects the sync object members on *all* bos. Reading and setting these members will always be very quick, so the risc of heavy lock contention is microscopic. Note that waiting for sync objects will always take place outside of this lock. The bo device fence lock will eventually be replaced with a seqlock / rcu mechanism so we can determine that a bo is idle under a rcu / read seqlock. However this change will allow us to batch fencing and unreserving of buffers with a minimal amount of locking. Signed-off-by: Thomas Hellstrom Reviewed-by: Jerome Glisse Signed-off-by: Dave Airlie --- drivers/gpu/drm/ttm/ttm_execbuf_util.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'drivers/gpu/drm/ttm/ttm_execbuf_util.c') diff --git a/drivers/gpu/drm/ttm/ttm_execbuf_util.c b/drivers/gpu/drm/ttm/ttm_execbuf_util.c index 7dcc6470e2f5..c3a2100bace6 100644 --- a/drivers/gpu/drm/ttm/ttm_execbuf_util.c +++ b/drivers/gpu/drm/ttm/ttm_execbuf_util.c @@ -203,14 +203,15 @@ void ttm_eu_fence_buffer_objects(struct list_head *list, void *sync_obj) list_for_each_entry(entry, list, head) { struct ttm_buffer_object *bo = entry->bo; - struct ttm_bo_driver *driver = bo->bdev->driver; + struct ttm_bo_device *bdev = bo->bdev; + struct ttm_bo_driver *driver = bdev->driver; void *old_sync_obj; - spin_lock(&bo->lock); + spin_lock(&bdev->fence_lock); old_sync_obj = bo->sync_obj; bo->sync_obj = driver->sync_obj_ref(sync_obj); bo->sync_obj_arg = entry->new_sync_obj_arg; - spin_unlock(&bo->lock); + spin_unlock(&bdev->fence_lock); ttm_bo_unreserve(bo); entry->reserved = false; if (old_sync_obj) -- cgit v1.2.3