> On Aug 18, 2022, at 15:37, Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx> wrote: > > The pmd_huge() is used to validate if the pmd entry is mapped by a huge > page, also including the case of non-present (migration or hwpoisoned) > pmd entry on arm64 or x86 architectures. That means the pmd_pfn() can > not get the correct pfn number for the non-present pmd entry, which > will cause damon_get_page() to get an incorrect page struct (also > may be NULL by pfn_to_online_page()) to make the access statistics > incorrect. > > Moreover it does not make sense that we still waste time to get the > page of the non-present entry, just treat it as not-accessed and skip it, > that keeps consistent with non-present pte level entry. > > Thus adding a pmd entry present validation to fix above issues. > > Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx> > Reviewed-by: SeongJae Park <sj@xxxxxxxxxx> Reviewed-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> Thanks.
