FAILED: patch "[PATCH] drm/ttm: Fix ttm_bo_shrink() infinite LRU walk on backup" failed to apply to 6.18-stable tree

FAILED: patch "[PATCH] drm/ttm: Fix ttm_bo_shrink() infinite LRU walk on backup" failed to apply to 6.18-stable tree

[gregkh]

The patch below does not apply to the 6.18-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y
git checkout FETCH_HEAD
git cherry-pick -x 1d59f36e95f7f7134db0e313c9d787cb0adb2153
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026052056-ideology-finite-c38d@gregkh' --subject-prefix 'PATCH 6.18.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 1d59f36e95f7f7134db0e313c9d787cb0adb2153 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Hellstr=C3=B6m?= <thomas.hellstrom@linux.intel.com>
Date: Mon, 11 May 2026 18:24:43 +0200
Subject: [PATCH] drm/ttm: Fix ttm_bo_shrink() infinite LRU walk on backup
 failure
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Apply the same fix as b2ed01e7ad ("drm/ttm: Fix ttm_bo_swapout()
infinite LRU walk on swapout failure") to the ttm_bo_shrink() path.

Move del_bulk_move from before the backup to after success only,
using ttm_resource_del_bulk_move_unevictable() since the resource
is now unevictable once fully backed up.

Fixes: 70d645deac98 ("drm/ttm: Add helpers for shrinking")
Cc: Christian König <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: Dave Airlie <airlied@redhat.com>
Cc: dri-devel@lists.freedesktop.org
Cc: stable@vger.kernel.org # v6.15+
Assisted-by: GitHub_Copilot:claude-opus-4.6
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patch.msgid.link/20260511162443.24352-1-thomas.hellstrom@linux.intel.com
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>

diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index f83b7d5ec6c6..3e3c201a0222 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -1112,19 +1112,14 @@ long ttm_bo_shrink(struct ttm_operation_ctx *ctx, struct ttm_buffer_object *bo,
 	if (lret < 0)
 		return lret;
 
-	if (bo->bulk_move) {
-		spin_lock(&bdev->lru_lock);
-		ttm_resource_del_bulk_move(bo->resource, bo);
-		spin_unlock(&bdev->lru_lock);
-	}
-
 	lret = ttm_tt_backup(bdev, bo->ttm, (struct ttm_backup_flags)
 			     {.purge = flags.purge,
 			      .writeback = flags.writeback});
 
-	if (lret <= 0 && bo->bulk_move) {
+	if (lret > 0) {
 		spin_lock(&bdev->lru_lock);
-		ttm_resource_add_bulk_move(bo->resource, bo);
+		ttm_resource_del_bulk_move_unevictable(bo->resource, bo);
+		ttm_resource_move_to_lru_tail(bo->resource);
 		spin_unlock(&bdev->lru_lock);
 	}