Commit 84d5d76c authored by Matthew Brost's avatar Matthew Brost
Browse files

drm/ttm: Fix GPU MM stats during pool shrinking 



TTM pool shrinking frees pages by calling __free_pages() directly,
which bypasses updates to NR_GPU_ACTIVE and leaves GPU MM accounting
out of sync.

Introduce a helper, __free_pages_gpu_account(), and use it for all page
frees in ttm_pool.c so GPU MM statistics are updated consistently.

Reported-by: default avatarKenneth Crudup <kenny@panix.com>
Fixes: ae80122f ("drm/ttm: use gpu mm stats to track gpu memory allocations. (v4)")
Cc: Christian Koenig <christian.koenig@amd.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: David Airlie <airlied@gmail.com>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: default avatarMatthew Brost <matthew.brost@intel.com>
Tested-by: default avatarKenneth Crudup <kenny@panix.com>
Reviewed-by: default avatarDave Airlie <airlied@redhat.com>
Link: https://patch.msgid.link/20260502065338.2720646-1-matthew.brost@intel.com
parent 01eb80b7

drivers/gpu/drm/ttm/ttm_pool.c

+12 −6
Original line number Diff line number Diff line
@@ -206,6 +206,14 @@ static struct page *ttm_pool_alloc_page(struct ttm_pool *pool, gfp_t gfp_flags, 
	return NULL;

}



static void __free_pages_gpu_account(struct page *p, unsigned int order,

				     bool reclaim)

{

	mod_lruvec_page_state(p, reclaim ? NR_GPU_RECLAIM : NR_GPU_ACTIVE,

			      -(1 << order));

	__free_pages(p, order);

}



/* Reset the caching and pages of size 1 << order */

static void ttm_pool_free_page(struct ttm_pool *pool, enum ttm_caching caching,

			       unsigned int order, struct page *p, bool reclaim)
@@ -223,9 +231,7 @@ static void ttm_pool_free_page(struct ttm_pool *pool, enum ttm_caching caching, 
#endif



	if (!pool || !ttm_pool_uses_dma_alloc(pool)) {

		mod_lruvec_page_state(p, reclaim ? NR_GPU_RECLAIM : NR_GPU_ACTIVE,

				      -(1 << order));

		__free_pages(p, order);

		__free_pages_gpu_account(p, order, reclaim);

		return;

	}
@@ -606,7 +612,7 @@ static int ttm_pool_restore_commit(struct ttm_pool_tt_restore *restore, 
			 */

			ttm_pool_split_for_swap(restore->pool, p);

			copy_highpage(restore->alloced_page + i, p);

			__free_pages(p, 0);

			__free_pages_gpu_account(p, 0, false);

		}



		restore->restored_pages++;
@@ -1068,7 +1074,7 @@ long ttm_pool_backup(struct ttm_pool *pool, struct ttm_tt *tt, 
			if (flags->purge) {

				shrunken += num_pages;

				page->private = 0;

				__free_pages(page, order);

				__free_pages_gpu_account(page, order, false);

				memset(tt->pages + i, 0,

				       num_pages * sizeof(*tt->pages));

			}
@@ -1109,7 +1115,7 @@ long ttm_pool_backup(struct ttm_pool *pool, struct ttm_tt *tt, 
		}

		handle = shandle;

		tt->pages[i] = ttm_backup_handle_to_page_ptr(handle);

		put_page(page);

		__free_pages_gpu_account(page, 0, false);

		shrunken++;

	}