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authorRik van Riel <riel@redhat.com>2012-05-29 22:06:18 (GMT)
committerLinus Torvalds <torvalds@linux-foundation.org>2012-05-29 23:22:19 (GMT)
commite709ffd6169ccd259eb5874e853303e91e94e829 (patch)
tree796b56c2507b8581492da73e354d651c9dd7076b /mm/memory.c
parentedad9d2c337d43278a9d5aeb0ed531c2e838f8a6 (diff)
downloadlinux-fsl-qoriq-e709ffd6169ccd259eb5874e853303e91e94e829.tar.xz
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/memory.c')
-rw-r--r--mm/memory.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/memory.c b/mm/memory.c
index e40f675..2bf9e11 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2908,7 +2908,6 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
delayacct_set_flag(DELAYACCT_PF_SWAPIN);
page = lookup_swap_cache(entry);
if (!page) {
- grab_swap_token(mm); /* Contend for token _before_ read-in */
page = swapin_readahead(entry,
GFP_HIGHUSER_MOVABLE, vma, address);
if (!page) {
@@ -2938,6 +2937,7 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
}
locked = lock_page_or_retry(page, mm, flags);
+
delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
if (!locked) {
ret |= VM_FAULT_RETRY;