On Thu, 18 Aug 2022 15:37:43 +0800 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. > Do we have a Fixes: for this? What are the user-visible runtime effects of the bug? "make the access statistics incorrect" is rather vague. Do we feel that a cc:stable is warranted?
