Hillf Danton wrote: > On Sun, May 12, 2013 at 9:23 AM, Kirill A. Shutemov > <[email protected]> wrote: > > @@ -1120,7 +1119,7 @@ int do_huge_pmd_wp_page(struct mm_struct *mm, struct > > vm_area_struct *vma, > > > > page = pmd_page(orig_pmd); > > VM_BUG_ON(!PageCompound(page) || !PageHead(page)); > > - if (page_mapcount(page) == 1) { > > + if (PageAnon(page) && page_mapcount(page) == 1) { > > Could we avoid copying huge page if > no-one else is using it, no matter anon?
No. The page is still in page cache and can be later accessed later. We could isolate the page from page cache, but I'm not sure whether it's good idea. do_wp_page() does exectly the same for small pages, so let's keep it consistent. -- Kirill A. Shutemov -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
