| From | "Kirill A. Shutemov" <> | Subject | Re: [PATCHv3, RFC 32/34] thp: handle write-protect exception to file-backed huge pages | Date | Fri, 26 Apr 2013 18:31:04 +0300 (EEST) |
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Dave Hansen wrote: > > + if (!PageAnon(page)) { > > + add_mm_counter(mm, MM_FILEPAGES, -HPAGE_PMD_NR); > > + add_mm_counter(mm, MM_ANONPAGES, HPAGE_PMD_NR); > > + } > > This seems like a bit of a hack. Shouldn't we have just been accounting > to MM_FILEPAGES in the first place?
No, it's not.
It handles MAP_PRIVATE file mappings. The page was read first and accounted to MM_FILEPAGES and then COW'ed by anon page here, so we have to adjust counters. do_wp_page() has similar code.
-- Kirill A. Shutemov
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