On 04/12/2016 05:57 PM, Alex Deucher wrote: > From: Felix Kuehling <Felix.Kuehling@xxxxxxx> > > 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. I think for allocations larger than PAGE_SIZE, ttm_round_pot() will overestimate. You should probably use the smaller of the two. /Thomas > > Signed-off-by: Felix Kuehling <Felix.Kuehling@xxxxxxx> > Reviewed-by: Monk Liu <monk.liu@xxxxxxx> > Reviewed-by: Christian König <christian.koenig@xxxxxxx> > --- > 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; > } _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
