A fixed or non-mm-managed mapping is one which sets VMA_PFNMAP_BIT, VMA_MIXEDMAP_BIT or VMA_DONTEXPAND_BIT, which is precisely what VMA_SPECIAL_FLAGS tests for other than VMA_IO_BIT, which is safe to drop as mm-managed mappings may not set it.
Using these predicates rather than VMA_SPECIAL_FLAGS makes the check self-documenting and helps eliminate the confusion around 'special' flags. No functional change intended. Reviewed-by: Zi Yan <[email protected]> Acked-by: David Hildenbrand (Arm) <[email protected]> Signed-off-by: Lorenzo Stoakes (ARM) <[email protected]> --- mm/vmscan.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 3b318efa2916..7adffe8182b3 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -4418,8 +4418,8 @@ bool lru_gen_look_around(struct page_vma_mapped_walk *pvmw, unsigned int nr) if (spin_is_contended(pvmw->ptl)) return true; - /* exclude special VMAs containing anon pages from COW */ - if (vma->vm_flags & VM_SPECIAL) + /* exclude fixed and non-mm-managed VMAs containing anon pages from COW */ + if (!vma_is_mm_managed(vma) || vma_is_fixed_mapping(vma)) return true; /* avoid taking the LRU lock under the PTL when possible */ -- 2.55.0
