[PATCH 2/3] drm/xe: select TRANSPARENT_HUGEPAGE

[Matthew Brost <matthew.brost@intel.com>]

Xe is currently the only TTM driver that drives the TTM shrinker, and
hence the only user of TTM's incremental swap path. That path splits the
pool's higher-order compound folios one page at a time via
folio_split_driver_managed() so individual pages can be backed up to
shmem and freed under memory pressure.

folio_split_driver_managed() is part of the transparent hugepage split
machinery in mm/huge_memory.c, which is only built when
CONFIG_TRANSPARENT_HUGEPAGE is enabled. Select it from DRM_XE so the
split primitive is always available for the driver that needs it, rather
than forcing it on every TTM user.

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: 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: Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: "Liam R. Howlett" <liam@infradead.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Assisted-by: GitHub-Copilot:claude-opus-4.8
---
 drivers/gpu/drm/xe/Kconfig | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/xe/Kconfig b/drivers/gpu/drm/xe/Kconfig
index 4d7dcaff2b91..88a4f3d09d5f 100644
--- a/drivers/gpu/drm/xe/Kconfig
+++ b/drivers/gpu/drm/xe/Kconfig
@@ -11,6 +11,12 @@ config DRM_XE
 	# the shmem_readpage() which depends upon tmpfs
 	select SHMEM
 	select TMPFS
+	# Xe is the only TTM driver that exercises the TTM shrinker's
+	# incremental swap path, which splits the pool's compound folios one
+	# page at a time via folio_split_driver_managed(). That helper lives
+	# in the THP split machinery, so pull it in here rather than for all
+	# TTM users.
+	select TRANSPARENT_HUGEPAGE
 	select DRM_BUDDY
 	select DRM_CLIENT_SELECTION
 	select DRM_KMS_HELPER
-- 
2.34.1