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. Signed-off-by: Matthew Brost <[email protected]> Reviewed-by: Christian Koenig <[email protected]> Reviewed-by: Andi Shyti <[email protected]> --- This was part of a larger shrinker series in Xe and is unlikely to be merged soon, as it is stuck in review. Send this reviewed, low-hanging TTM patch on its own, as it slightly helps address Xe's shrinker issues. --- 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 278bbe7a11ad..e76c3a5c67bd 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
