On 23/09/2021 08:55, Christian König wrote:
This makes the function much simpler since the complex
retry logic is now handled else where.
Please mention the increased cost versus the old implementation (two
atomics per fence when walking vs no atomics).
Regards,
Tvrtko
Signed-off-by: Christian König <christian.koenig@xxxxxxx>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
---
drivers/gpu/drm/i915/gem/i915_gem_busy.c | 35 ++++++++++--------------
1 file changed, 14 insertions(+), 21 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_busy.c b/drivers/gpu/drm/i915/gem/i915_gem_busy.c
index 6234e17259c1..dc72b36dae54 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_busy.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_busy.c
@@ -82,8 +82,8 @@ i915_gem_busy_ioctl(struct drm_device *dev, void *data,
{
struct drm_i915_gem_busy *args = data;
struct drm_i915_gem_object *obj;
- struct dma_resv_list *list;
- unsigned int seq;
+ struct dma_resv_iter cursor;
+ struct dma_fence *fence;
int err;
err = -ENOENT;
@@ -109,27 +109,20 @@ i915_gem_busy_ioctl(struct drm_device *dev, void *data,
* to report the overall busyness. This is what the wait-ioctl does.
*
*/
-retry:
- seq = raw_read_seqcount(&obj->base.resv->seq);
-
- /* Translate the exclusive fence to the READ *and* WRITE engine */
- args->busy = busy_check_writer(dma_resv_excl_fence(obj->base.resv));
-
- /* Translate shared fences to READ set of engines */
- list = dma_resv_shared_list(obj->base.resv);
- if (list) {
- unsigned int shared_count = list->shared_count, i;
-
- for (i = 0; i < shared_count; ++i) {
- struct dma_fence *fence =
- rcu_dereference(list->shared[i]);
-
+ args->busy = 0;
+ dma_resv_iter_begin(&cursor, obj->base.resv, true);
+ dma_resv_for_each_fence_unlocked(&cursor, fence) {
+ if (dma_resv_iter_is_restarted(&cursor))
+ args->busy = 0;
+
+ if (dma_resv_iter_is_exclusive(&cursor))
+ /* Translate the exclusive fence to the READ *and* WRITE engine */
+ args->busy |= busy_check_writer(fence);
+ else
+ /* Translate shared fences to READ set of engines */
args->busy |= busy_check_reader(fence);
- }
}
-
- if (args->busy && read_seqcount_retry(&obj->base.resv->seq, seq))
- goto retry;
+ dma_resv_iter_end(&cursor);
err = 0;
out:
