In commit:
commit 1e6decf30af5c5c75445ed6ad4e65a26de578a03
Author: Hugh Dickins <hughd@xxxxxxxxxx>
Date: Thu Sep 2 14:54:43 2021 -0700
shmem: shmem_writepage() split unlikely i915 THP
it looks THP + shmem_writeback was an unexpected combination, and ends up
hitting some BUG_ON, but it also looks like that is now fixed.
While the IGTs did eventually hit this(although not during pre-merge it
seems), it's likely worthwhile adding some explicit coverage for this
scenario in the shrink_thp selftest.
References: https://gitlab.freedesktop.org/drm/intel/-/issues/4166
Signed-off-by: Matthew Auld <matthew.auld@xxxxxxxxx>
Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/gem/selftests/huge_pages.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
index 0827634c842c..8260a533d43f 100644
--- a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
+++ b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
@@ -1589,7 +1589,8 @@ static int igt_shrink_thp(void *arg)
i915_gem_shrink(NULL, i915, -1UL, NULL,
I915_SHRINK_BOUND |
I915_SHRINK_UNBOUND |
- I915_SHRINK_ACTIVE);
+ I915_SHRINK_ACTIVE |
+ I915_SHRINK_WRITEBACK);
if (should_swap == i915_gem_object_has_pages(obj)) {
pr_err("unexpected pages mismatch, should_swap=%s\n",
yesno(should_swap));
--
2.26.3
