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authorRik van Riel <riel@redhat.com>2012-05-29 15:06:18 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-05-29 16:22:19 -0700
commite709ffd6169ccd259eb5874e853303e91e94e829 (patch)
tree796b56c2507b8581492da73e354d651c9dd7076b /mm/rmap.c
parentedad9d2c337d43278a9d5aeb0ed531c2e838f8a6 (diff)
mm: remove swap token code
The swap token code no longer fits in with the current VM model. It does not play well with cgroups or the better NUMA placement code in development, since we have only one swap token globally. It also has the potential to mess with scalability of the system, by increasing the number of non-reclaimable pages on the active and inactive anon LRU lists. Last but not least, the swap token code has been broken for a year without complaints, as reported by Konstantin Khlebnikov. This suggests we no longer have much use for it. The days of sub-1G memory systems with heavy use of swap are over. If we ever need thrashing reducing code in the future, we will have to implement something that does scale. Signed-off-by: Rik van Riel <riel@redhat.com> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Hugh Dickins <hughd@google.com> Acked-by: Bob Picco <bpicco@meloft.net> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/rmap.c')
-rw-r--r--mm/rmap.c6
1 files changed, 0 insertions, 6 deletions
diff --git a/mm/rmap.c b/mm/rmap.c
index 5b5ad584ffb..0f3b7cda2a2 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -755,12 +755,6 @@ int page_referenced_one(struct page *page, struct vm_area_struct *vma,
pte_unmap_unlock(pte, ptl);
}
- /* Pretend the page is referenced if the task has the
- swap token and is in the middle of a page fault. */
- if (mm != current->mm && has_swap_token(mm) &&
- rwsem_is_locked(&mm->mmap_sem))
- referenced++;
-
(*mapcount)--;
if (referenced)