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| author | Johannes Weiner <hannes@cmpxchg.org> | 2013-02-22 16:32:15 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-02-23 17:50:09 -0800 |
| commit | 11d16c25bbf7a3b7a43d7472e175cdd52961757d (patch) | |
| tree | 6e87963a0373ac627500baa84ff43164fee46bc7 /mm/vmscan.c | |
| parent | 10316b313cbde4b778c3d1b4b2fe2adbcbe84a48 (diff) | |
| download | lwn-11d16c25bbf7a3b7a43d7472e175cdd52961757d.tar.gz lwn-11d16c25bbf7a3b7a43d7472e175cdd52961757d.zip | |
mm: vmscan: improve comment on low-page cache handling
Fix comment style and elaborate on why anonymous memory is force-scanned
when file cache runs low.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Satoru Moriya <satoru.moriya@hds.com>
Cc: Simon Jeons <simon.jeons@gmail.com>
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.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index 68586c887611..259f8208a388 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1713,13 +1713,15 @@ static void get_scan_count(struct lruvec *lruvec, struct scan_control *sc, file = get_lru_size(lruvec, LRU_ACTIVE_FILE) + get_lru_size(lruvec, LRU_INACTIVE_FILE); + /* + * If it's foreseeable that reclaiming the file cache won't be + * enough to get the zone back into a desirable shape, we have + * to swap. Better start now and leave the - probably heavily + * thrashing - remaining file pages alone. + */ if (global_reclaim(sc)) { - free = zone_page_state(zone, NR_FREE_PAGES); + free = zone_page_state(zone, NR_FREE_PAGES); if (unlikely(file + free <= high_wmark_pages(zone))) { - /* - * If we have very few page cache pages, force-scan - * anon pages. - */ fraction[0] = 1; fraction[1] = 0; denominator = 1; |