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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 /include/linux/swap.h
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 'include/linux/swap.h')
-rw-r--r--include/linux/swap.h35
1 files changed, 0 insertions, 35 deletions
diff --git a/include/linux/swap.h b/include/linux/swap.h
index b1fd5c7925fe..bc3073ce95cc 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -355,23 +355,6 @@ extern int reuse_swap_page(struct page *);
extern int try_to_free_swap(struct page *);
struct backing_dev_info;
-/* linux/mm/thrash.c */
-extern struct mm_struct *swap_token_mm;
-extern void grab_swap_token(struct mm_struct *);
-extern void __put_swap_token(struct mm_struct *);
-extern void disable_swap_token(struct mem_cgroup *memcg);
-
-static inline int has_swap_token(struct mm_struct *mm)
-{
- return (mm == swap_token_mm);
-}
-
-static inline void put_swap_token(struct mm_struct *mm)
-{
- if (has_swap_token(mm))
- __put_swap_token(mm);
-}
-
#ifdef CONFIG_CGROUP_MEM_RES_CTLR
extern void
mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout);
@@ -476,24 +459,6 @@ static inline swp_entry_t get_swap_page(void)
return entry;
}
-/* linux/mm/thrash.c */
-static inline void put_swap_token(struct mm_struct *mm)
-{
-}
-
-static inline void grab_swap_token(struct mm_struct *mm)
-{
-}
-
-static inline int has_swap_token(struct mm_struct *mm)
-{
- return 0;
-}
-
-static inline void disable_swap_token(struct mem_cgroup *memcg)
-{
-}
-
static inline void
mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent)
{