Messages in this thread Patch in this message | | | Date | Mon, 2 Dec 2019 11:03:15 +0300 | From | "Kirill A. Shutemov" <> | Subject | Re: [PATCH 1/2] mm/page_vma_mapped: use PMD_SIZE instead of calculating it |
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On Thu, Nov 28, 2019 at 09:22:26PM +0000, Wei Yang wrote: > On Thu, Nov 28, 2019 at 11:32:55AM +0300, Kirill A. Shutemov wrote: > >On Thu, Nov 28, 2019 at 09:03:20AM +0800, Wei Yang wrote: > >> At this point, we are sure page is PageTransHuge, which means > >> hpage_nr_pages is HPAGE_PMD_NR. > >> > >> This is safe to use PMD_SIZE instead of calculating it. > >> > >> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com> > >> --- > >> mm/page_vma_mapped.c | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c > >> index eff4b4520c8d..76e03650a3ab 100644 > >> --- a/mm/page_vma_mapped.c > >> +++ b/mm/page_vma_mapped.c > >> @@ -223,7 +223,7 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw) > >> if (pvmw->address >= pvmw->vma->vm_end || > >> pvmw->address >= > >> __vma_address(pvmw->page, pvmw->vma) + > >> - hpage_nr_pages(pvmw->page) * PAGE_SIZE) > >> + PMD_SIZE) > >> return not_found(pvmw); > >> /* Did we cross page table boundary? */ > >> if (pvmw->address % PMD_SIZE == 0) { > > > >It is dubious cleanup. Maybe page_size(pvmw->page) instead? It will not > >break if we ever get PUD THP pages. > > > > Thanks for your comment. > > I took a look into the code again and found I may miss something. > > I found we support PUD THP pages, whilc hpage_nr_pages() just return > HPAGE_PMD_NR on PageTransHuge. Why this is not possible to return PUD number?
We only support PUD THP for DAX. Means, we don't have struct page for it.
-- Kirill A. Shutemov
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