On Thu Sep 17, 2026 at 12:22 PM EDT, Lorenzo Stoakes (ARM) wrote: > It is now an invariant that VMA_IO_BIT is not set except by kernel-owned > mappings, so each existing VMA_SPECIAL_FLAGS test need only test for > VMA_DONTEXPAND_BIT, VMA_PFNMAP_BIT and VMA_MIXEDMAP_BIT. > > This is precisely a test for a kernel-owned or fixed mapping. > > Update a number of callsites which already explicitly handle hugetlb > mappings. > > vma_supports_mlock() and ksm_compatible() also explicitly bail on droppable > mappings - detecting kernel-owned, fixed or droppable mappings is handled > by vma_is_persistent(), so in these cases use this predicate. > > should_skip_vma() tests for locked, kernel-owned or fixed memory (having > already excluded hugetlb mappings) so simply test for those there. > > No functional change intended. > > Signed-off-by: Lorenzo Stoakes (ARM) <[email protected]> > --- > mm/internal.h | 4 +--- > mm/ksm.c | 4 +--- > mm/vmscan.c | 3 ++- > 3 files changed, 4 insertions(+), 7 deletions(-) >
<snip> > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 12ed3388ee41..09ff20c3df5b 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -3477,7 +3477,8 @@ static int should_skip_vma(unsigned long start, > unsigned long end, struct mm_wal > if (!vma_has_recency(vma)) > return true; > > - if (vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) > + if (vma_test(vma, VMA_LOCKED_BIT) || vma_is_kernel_owned(vma) || At this point, mmap_lock is held, there is no mlock WIP, so VMA_LOCKED_BIT is enough. > + vma_is_fixed_mapping(vma)) > return true; > > if (vma == get_gate_vma(vma->vm_mm)) LGTM. Reviewed-by: Zi Yan <[email protected]> -- Best Regards, Yan, Zi
