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authorMichal Hocko <mhocko@suse.com>2017-02-22 15:45:55 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-02-22 16:41:30 -0800
commitf0958906cd2bf3730cd7938b8af80a1c23e8ac06 (patch)
tree15d54ac8207f998554d5a35e1273322ae52136ac /mm/vmscan.c
parentbc71226b0690c21bdf50c9c9d08c5dc9ef98764e (diff)
downloadop-kernel-dev-f0958906cd2bf3730cd7938b8af80a1c23e8ac06.zip
op-kernel-dev-f0958906cd2bf3730cd7938b8af80a1c23e8ac06.tar.gz
mm, vmscan: do not count freed pages as PGDEACTIVATE
PGDEACTIVATE represents the number of pages moved from the active list to the inactive list. At least this sounds like the original motivation of the counter. move_active_pages_to_lru, however, counts pages which got freed in the mean time as deactivated as well. This is a very rare event and counting them as deactivation in itself is not harmful but it makes the code more convoluted than necessary - we have to count both all pages and those which are freed which is a bit confusing. After this patch the PGDEACTIVATE should have a slightly more clear semantic and only count those pages which are moved from the active to the inactive list which is a plus. Link: http://lkml.kernel.org/r/20170112211221.17636-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Suggested-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/vmscan.c')
-rw-r--r--mm/vmscan.c4
1 files changed, 1 insertions, 3 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c
index de400d1..277e105 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1878,7 +1878,6 @@ static unsigned move_active_pages_to_lru(struct lruvec *lruvec,
enum lru_list lru)
{
struct pglist_data *pgdat = lruvec_pgdat(lruvec);
- unsigned long pgmoved = 0;
struct page *page;
int nr_pages;
int nr_moved = 0;
@@ -1893,7 +1892,6 @@ static unsigned move_active_pages_to_lru(struct lruvec *lruvec,
nr_pages = hpage_nr_pages(page);
update_lru_size(lruvec, lru, page_zonenum(page), nr_pages);
list_move(&page->lru, &lruvec->lists[lru]);
- pgmoved += nr_pages;
if (put_page_testzero(page)) {
__ClearPageLRU(page);
@@ -1913,7 +1911,7 @@ static unsigned move_active_pages_to_lru(struct lruvec *lruvec,
}
if (!is_active_lru(lru))
- __count_vm_events(PGDEACTIVATE, pgmoved);
+ __count_vm_events(PGDEACTIVATE, nr_moved);
return nr_moved;
}
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