On Tue, Sep 29, 2026 at 10:42:00PM -0400, Zi Yan wrote: > 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.
Yes indeed :) > > > + vma_is_fixed_mapping(vma)) > > return true; > > > > if (vma == get_gate_vma(vma->vm_mm)) > > LGTM. > > Reviewed-by: Zi Yan <[email protected]> Thanks! > > > -- > Best Regards, > Yan, Zi > -- Cheers, Lorenzo
