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| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2016-02-03 01:57:12 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-02-03 17:28:43 +0100 |
| commit | cb8d68ec16a511f8be7e1028fd8f869ef7c6a1a8 (patch) | |
| tree | bca734285ef34b21cbdc7d3c3873981c41c76d4e /mm/huge_memory.c | |
| parent | thp: make split_queue per-node (diff) | |
| download | linux-cb8d68ec16a511f8be7e1028fd8f869ef7c6a1a8.tar.xz linux-cb8d68ec16a511f8be7e1028fd8f869ef7c6a1a8.zip | |
thp: change deferred_split_count() to return number of THP in queue
I've got meaning of shrinker::count_objects() wrong: it should return
number of potentially freeable objects, which is not necessary correlate
with freeable memory.
Returning 256 per THP in queue is not reasonable:
shrinker::scan_objects() never called with nr_to_scan > 128 in my setup.
Let's return 1 per THP and correct scan_object accordingly.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/huge_memory.c')
| -rw-r--r-- | mm/huge_memory.c | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 253a25e007d7..7aae72114583 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -3465,12 +3465,7 @@ static unsigned long deferred_split_count(struct shrinker *shrink, struct shrink_control *sc) { struct pglist_data *pgdata = NODE_DATA(sc->nid); - /* - * Split a page from split_queue will free up at least one page, - * at most HPAGE_PMD_NR - 1. We don't track exact number. - * Let's use HPAGE_PMD_NR / 2 as ballpark. - */ - return ACCESS_ONCE(pgdata->split_queue_len) * HPAGE_PMD_NR / 2; + return ACCESS_ONCE(pgdata->split_queue_len); } static unsigned long deferred_split_scan(struct shrinker *shrink, @@ -3511,7 +3506,13 @@ static unsigned long deferred_split_scan(struct shrinker *shrink, list_splice_tail(&list, &pgdata->split_queue); spin_unlock_irqrestore(&pgdata->split_queue_lock, flags); - return split * HPAGE_PMD_NR / 2; + /* + * Stop shrinker if we didn't split any page, but the queue is empty. + * This can happen if pages were freed under us. + */ + if (!split && list_empty(&pgdata->split_queue)) + return SHRINK_STOP; + return split; } static struct shrinker deferred_split_shrinker = { |