drm/ttm: rework no_retry handling v2

During eviction we do want to trigger the OOM killer.

Only while doing new allocations we should try to avoid that and
return -ENOMEM to the application.

v2: rename the flag to gfp_retry_mayfail.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/398685/

drivers/gpu/drm/amd/amdgpu/amdgpu_object.c

@@ -516,6 +516,8 @@ static int amdgpu_bo_do_create(struct amdgpu_device *adev,
 	struct ttm_operation_ctx ctx = {
 		.interruptible = (bp->type != ttm_bo_type_kernel),
 		.no_wait_gpu = bp->no_wait_gpu,
+		/* We opt to avoid OOM on system pages allocations */
+		.gfp_retry_mayfail = true,
 		.resv = bp->resv,
 		.flags = bp->type != ttm_bo_type_kernel ?
 			TTM_OPT_FLAG_ALLOW_RES_EVICT : 0

drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c

@@ -1914,9 +1914,6 @@ int amdgpu_ttm_init(struct amdgpu_device *adev)
 	}
 	adev->mman.initialized = true;
 
-	/* We opt to avoid OOM on system pages allocations */
-	adev->mman.bdev.no_retry = true;
-
 	/* Initialize VRAM pool with all of VRAM divided into pages */
 	r = amdgpu_vram_mgr_init(adev);
 	if (r) {

drivers/gpu/drm/ttm/ttm_pool.c

@@ -367,7 +367,7 @@ int ttm_pool_alloc(struct ttm_pool *pool, struct ttm_tt *tt,
 	if (tt->page_flags & TTM_PAGE_FLAG_ZERO_ALLOC)
 		gfp_flags |= __GFP_ZERO;
 
-	if (tt->page_flags & TTM_PAGE_FLAG_NO_RETRY)
+	if (ctx->gfp_retry_mayfail)
 		gfp_flags |= __GFP_RETRY_MAYFAIL;
 
 	if (pool->use_dma32)

drivers/gpu/drm/ttm/ttm_tt.c

@@ -51,9 +51,6 @@ int ttm_tt_create(struct ttm_buffer_object *bo, bool zero_alloc)
 	if (bo->ttm)
 		return 0;
 
-	if (bdev->no_retry)
-		page_flags |= TTM_PAGE_FLAG_NO_RETRY;
-
 	switch (bo->type) {
 	case ttm_bo_type_device:
 		if (zero_alloc)
@@ -211,8 +208,6 @@ int ttm_tt_swapin(struct ttm_tt *ttm)
 
 	swap_space = swap_storage->f_mapping;
 	gfp_mask = mapping_gfp_mask(swap_space);
-	if (ttm->page_flags & TTM_PAGE_FLAG_NO_RETRY)
-		gfp_mask |= __GFP_RETRY_MAYFAIL;
 
 	for (i = 0; i < ttm->num_pages; ++i) {
 		from_page = shmem_read_mapping_page_gfp(swap_space, i,
@@ -260,8 +255,6 @@ int ttm_tt_swapout(struct ttm_bo_device *bdev, struct ttm_tt *ttm)
 
 	swap_space = swap_storage->f_mapping;
 	gfp_mask = mapping_gfp_mask(swap_space);
-	if (ttm->page_flags & TTM_PAGE_FLAG_NO_RETRY)
-		gfp_mask |= __GFP_RETRY_MAYFAIL;
 
 	for (i = 0; i < ttm->num_pages; ++i) {
 		from_page = ttm->pages[i];

include/drm/ttm/ttm_bo_api.h

@@ -195,6 +195,7 @@ struct ttm_bo_kmap_obj {
  *
  * @interruptible: Sleep interruptible if sleeping.
  * @no_wait_gpu: Return immediately if the GPU is busy.
+ * @gfp_retry_mayfail: Set the __GFP_RETRY_MAYFAIL when allocation pages.
  * @resv: Reservation object to allow reserved evictions with.
  * @flags: Including the following flags
  *
@@ -204,6 +205,7 @@ struct ttm_bo_kmap_obj {
 struct ttm_operation_ctx {
 	bool interruptible;
 	bool no_wait_gpu;
+	bool gfp_retry_mayfail;
 	struct dma_resv *resv;
 	uint64_t bytes_moved;
 	uint32_t flags;

include/drm/ttm/ttm_bo_driver.h

@@ -276,7 +276,6 @@ extern struct ttm_bo_global {
  * @dev_mapping: A pointer to the struct address_space representing the
  * device address space.
  * @wq: Work queue structure for the delayed delete workqueue.
- * @no_retry: Don't retry allocation if it fails
  *
  */
 
@@ -314,8 +313,6 @@ struct ttm_bo_device {
 	 */
 
 	struct delayed_work wq;
-
-	bool no_retry;
 };
 
 static inline struct ttm_resource_manager *ttm_manager_type(struct ttm_bo_device *bdev,