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| author | Hugh Dickins <hughd@google.com> | 2013-02-22 16:35:13 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-02-23 17:50:19 -0800 |
| commit | b79bc0a0c79e06cc87e17530e9c1c56c6f297e17 (patch) | |
| tree | 617d8e3b2d8be512373c3351a92630c28248ecee /mm/mempolicy.c | |
| parent | 4146d2d673e8d6abf9b30a5b5dd8cd95f29632eb (diff) | |
| download | blackbird-obmc-linux-b79bc0a0c79e06cc87e17530e9c1c56c6f297e17.tar.gz blackbird-obmc-linux-b79bc0a0c79e06cc87e17530e9c1c56c6f297e17.zip | |
ksm: enable KSM page migration
Migration of KSM pages is now safe: remove the PageKsm restrictions from
mempolicy.c and migrate.c.
But keep PageKsm out of __unmap_and_move()'s anon_vma contortions, which
are irrelevant to KSM: it looks as if that code was preventing hotremove
migration of KSM pages, unless they happened to be in swapcache.
There is some question as to whether enforcing a NUMA mempolicy migration
ought to migrate KSM pages, mapped into entirely unrelated processes; but
moving page_mapcount > 1 is only permitted with MPOL_MF_MOVE_ALL anyway,
and it seems reasonable to assume that you wouldn't set MADV_MERGEABLE on
any area where this is a worry.
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Petr Holasek <pholasek@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Izik Eidus <izik.eidus@ravellosystems.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/mempolicy.c')
| -rw-r--r-- | mm/mempolicy.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 2ae78e255e08..d344c36db63f 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -496,9 +496,8 @@ static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd, /* * vm_normal_page() filters out zero pages, but there might * still be PageReserved pages to skip, perhaps in a VDSO. - * And we cannot move PageKsm pages sensibly or safely yet. */ - if (PageReserved(page) || PageKsm(page)) + if (PageReserved(page)) continue; nid = page_to_nid(page); if (node_isset(nid, *nodes) == !!(flags & MPOL_MF_INVERT)) |
