[PATCH v2 2/5] drm/ttm: Issue direct reclaim at beneficial_order

Matthew Brost
2026-04-23T05:57:05Z

Triggering kswap at an order higher than beneficial_order makes little
sense, as the driver has already indicated the optimal order at which
reclaim is effective. Similarly, issuing direct reclaim or triggering
kswap at a lower order than beneficial_order is ineffective, since the
driver does not benefit from reclaiming lower-order pages.

As a result, direct reclaim should only be issued with __GFP_NORETRY at
exactly beneficial_order, or as a fallback, direct reclaim without
__GFP_NORETRY at order 0 when failure is not an option.

Cc: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Carlos Santa <carlos.santa@intel.com>
Cc: Christian Koenig <christian.koenig@amd.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: David Airlie <airlied@gmail.com>
Cc: Simona Vetter <simona@ffwll.ch>
CC: dri-devel@lists.freedesktop.org
Cc: Daniel Colascione <dancol@dancol.org>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Christian Koenig <christian.koenig@amd.com>
---
drivers/gpu/drm/ttm/ttm_pool.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_pool.c b/drivers/gpu/drm/ttm/ttm_pool.c
index 26a3689e5fd9..8425dbcc6c68 100644
--- a/drivers/gpu/drm/ttm/ttm_pool.c
+++ b/drivers/gpu/drm/ttm/ttm_pool.c
@@ -165,8 +165,8 @@ static struct page *ttm_pool_alloc_page(struct ttm_pool *pool, gfp_t gfp_flags,
* Do not add latency to the allocation path for allocations orders
* device tolds us do not bring them additional performance gains.
*/
- if (beneficial_order && order > beneficial_order)
- gfp_flags &= ~__GFP_DIRECT_RECLAIM;
+ if (order && beneficial_order && order != beneficial_order)
+ gfp_flags &= ~__GFP_RECLAIM;

if (!ttm_pool_uses_dma_alloc(pool)) {
p = alloc_pages_node(pool->nid, gfp_flags, order);
--
2.34.1