Problem: Under memory pressure when GTT domain is almost full multihop assert will come up when trying to evict LRU BO from VRAM to SYSTEM.
Fix: Don't assert on multihop error in evict code but rather do a retry as we do in ttm_bo_move_buffer
Signed-off-by: Andrey Grodzovsky andrey.grodzovsky@amd.com --- drivers/gpu/drm/ttm/ttm_bo.c | 63 +++++++++++++++++++----------------- 1 file changed, 34 insertions(+), 29 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c index 45145d02aed2..5a2dc712c632 100644 --- a/drivers/gpu/drm/ttm/ttm_bo.c +++ b/drivers/gpu/drm/ttm/ttm_bo.c @@ -485,6 +485,31 @@ void ttm_bo_unlock_delayed_workqueue(struct ttm_device *bdev, int resched) } EXPORT_SYMBOL(ttm_bo_unlock_delayed_workqueue);
+static int ttm_bo_bounce_temp_buffer(struct ttm_buffer_object *bo, + struct ttm_resource **mem, + struct ttm_operation_ctx *ctx, + struct ttm_place *hop) +{ + struct ttm_placement hop_placement; + struct ttm_resource *hop_mem; + int ret; + + hop_placement.num_placement = hop_placement.num_busy_placement = 1; + hop_placement.placement = hop_placement.busy_placement = hop; + + /* find space in the bounce domain */ + ret = ttm_bo_mem_space(bo, &hop_placement, &hop_mem, ctx); + if (ret) + return ret; + /* move to the bounce domain */ + ret = ttm_bo_handle_move_mem(bo, hop_mem, false, ctx, NULL); + if (ret) { + ttm_resource_free(bo, &hop_mem); + return ret; + } + return 0; +} + static int ttm_bo_evict(struct ttm_buffer_object *bo, struct ttm_operation_ctx *ctx) { @@ -524,12 +549,17 @@ static int ttm_bo_evict(struct ttm_buffer_object *bo, goto out; }
+bounce: ret = ttm_bo_handle_move_mem(bo, evict_mem, true, ctx, &hop); - if (unlikely(ret)) { - WARN(ret == -EMULTIHOP, "Unexpected multihop in eviction - likely driver bug\n"); - if (ret != -ERESTARTSYS) + if (ret == -EMULTIHOP) { + ret = ttm_bo_bounce_temp_buffer(bo, &evict_mem, ctx, &hop); + if (ret) { pr_err("Buffer eviction failed\n"); - ttm_resource_free(bo, &evict_mem); + ttm_resource_free(bo, &evict_mem); + goto out; + } + /* try and move to final place now. */ + goto bounce; } out: return ret; @@ -844,31 +874,6 @@ int ttm_bo_mem_space(struct ttm_buffer_object *bo, } EXPORT_SYMBOL(ttm_bo_mem_space);
-static int ttm_bo_bounce_temp_buffer(struct ttm_buffer_object *bo, - struct ttm_resource **mem, - struct ttm_operation_ctx *ctx, - struct ttm_place *hop) -{ - struct ttm_placement hop_placement; - struct ttm_resource *hop_mem; - int ret; - - hop_placement.num_placement = hop_placement.num_busy_placement = 1; - hop_placement.placement = hop_placement.busy_placement = hop; - - /* find space in the bounce domain */ - ret = ttm_bo_mem_space(bo, &hop_placement, &hop_mem, ctx); - if (ret) - return ret; - /* move to the bounce domain */ - ret = ttm_bo_handle_move_mem(bo, hop_mem, false, ctx, NULL); - if (ret) { - ttm_resource_free(bo, &hop_mem); - return ret; - } - return 0; -} - static int ttm_bo_move_buffer(struct ttm_buffer_object *bo, struct ttm_placement *placement, struct ttm_operation_ctx *ctx)