Clearing the buffer object bulk move is closely tied to individualizing the resv, since that is when we effectively detach the bo from a vm.
Clearing the bulk move also requires the bo resv, which we have readily locked at individualizing time without clobbering the much wider vm lock. So Clear the buffer object bulk_move at individualizing time, and update the code comments. Signed-off-by: Thomas Hellström <[email protected]> --- drivers/gpu/drm/ttm/ttm_bo.c | 30 ++++++++++++++++++++++-------- 1 file changed, 22 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c index bd5dae4d1624..57cc9f845adc 100644 --- a/drivers/gpu/drm/ttm/ttm_bo.c +++ b/drivers/gpu/drm/ttm/ttm_bo.c @@ -193,20 +193,33 @@ static int ttm_bo_individualize_resv(struct ttm_buffer_object *bo) BUG_ON(!dma_resv_trylock(&bo->base._resv)); r = dma_resv_copy_fences(&bo->base._resv, bo->base.resv); - dma_resv_unlock(&bo->base._resv); - if (r) - return r; - if (bo->type != ttm_bo_type_sg) { - /* This works because the BO is about to be destroyed and nobody - * reference it any more. The only tricky case is the trylock on - * the resv object while holding the lru_lock. + if (!r && bo->type != ttm_bo_type_sg) { + /* + * The TTM bo refcount is now zero and hence nobody will + * therefore try to lock the bo at this point: the LRU + * list lookups will trylock even if the refcount is zero, + * but will only do that under the LRU lock and will + * then immediately back off under the same LRU lock when it + * sees the zero refcount. */ spin_lock(&bo->bdev->lru_lock); bo->base.resv = &bo->base._resv; + + /* Since bulk move is closely tied with the shared resv, + * clear it when we have now individualized, if that was not + * done by the driver already. + */ + if (bo->bulk_move) { + if (bo->resource) + ttm_resource_del_bulk_move(bo->resource, bo); + bo->bulk_move = NULL; + } spin_unlock(&bo->bdev->lru_lock); } + dma_resv_unlock(&bo->base._resv); + return r; } @@ -324,7 +337,6 @@ static void ttm_bo_release(struct kref *kref) int ret; WARN_ON_ONCE(bo->pin_count); - WARN_ON_ONCE(bo->bulk_move); if (!bo->deleted) { ret = ttm_bo_individualize_resv(bo); @@ -337,6 +349,8 @@ static void ttm_bo_release(struct kref *kref) 30 * HZ); } + WARN_ON_ONCE(bo->bulk_move); + if (bo->bdev->funcs->release_notify) bo->bdev->funcs->release_notify(bo); -- 2.39.2
