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

[Andi Shyti <andi.shyti@kernel.org>]

Hi Matt,

On Wed, Apr 22, 2026 at 10:56:53PM -0700, Matthew Brost wrote:
> 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>

Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>

Thanks,
Andi