From: Felix Kuehling Felix.Kuehling@amd.com
TTM BO accounting is out of sync with how memory is really allocated in ttm[_dma]_tt_alloc_page_directory. This resulted in excessive estimated overhead with many small allocations.
ttm_dma_tt_alloc_page_directory makes a single allocation for three arrays: pages, DMA and CPU addresses. It uses drm_calloc_large, which uses kmalloc internally for allocations smaller than PAGE_SIZE. ttm_round_pot should be a good approximation of its memory usage both above and below PAGE_SIZE.
Signed-off-by: Felix Kuehling Felix.Kuehling@amd.com Reviewed-by: Monk Liu monk.liu@amd.com Reviewed-by: Christian König christian.koenig@amd.com --- drivers/gpu/drm/ttm/ttm_bo.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c index 4cbf265..870a87a 100644 --- a/drivers/gpu/drm/ttm/ttm_bo.c +++ b/drivers/gpu/drm/ttm/ttm_bo.c @@ -1215,7 +1215,7 @@ size_t ttm_bo_acc_size(struct ttm_bo_device *bdev, size_t size = 0;
size += ttm_round_pot(struct_size); - size += PAGE_ALIGN(npages * sizeof(void *)); + size += ttm_round_pot(npages * sizeof(void *)); size += ttm_round_pot(sizeof(struct ttm_tt)); return size; } @@ -1229,8 +1229,7 @@ size_t ttm_bo_dma_acc_size(struct ttm_bo_device *bdev, size_t size = 0;
size += ttm_round_pot(struct_size); - size += PAGE_ALIGN(npages * sizeof(void *)); - size += PAGE_ALIGN(npages * sizeof(dma_addr_t)); + size += ttm_round_pot(npages * (2*sizeof(void *) + sizeof(dma_addr_t))); size += ttm_round_pot(sizeof(struct ttm_dma_tt)); return size; }