Re: [PATCHv4 37/39] thp: handle write-protect exception to file-backed huge pages

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hillf Danton wrote:
> On Sun, May 12, 2013 at 9:23 AM, Kirill A. Shutemov
> <kirill.shutemov@xxxxxxxxxxxxxxx> 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-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux Ext4 Filesystem]     [Union Filesystem]     [Filesystem Testing]     [Ceph Users]     [Ecryptfs]     [AutoFS]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux Cachefs]     [Reiser Filesystem]     [Linux RAID]     [Samba]     [Device Mapper]     [CEPH Development]
  Powered by Linux