In commit:
commit 1e6decf30a
Author: Hugh Dickins <hughd@google.com>
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@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210921142116.3807946-1-matthew.auld@intel.com
6341eb6f39