From: Glauber Costa <[email protected]> In very low free kernel memory situations, it may be the case that we have less objects to free than our initial batch size. If this is the case, it is better to shrink those, and open space for the new workload then to keep them and fail the new allocations.
In particular, we are concerned with the direct reclaim case for memcg. Although this same technique can be applied to other situations just as well, we will start conservative and apply it for that case, which is the one that matters the most. Signed-off-by: Glauber Costa <[email protected]> Signed-off-by: Vladimir Davydov <[email protected]> Cc: Dave Chinner <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Mel Gorman <[email protected]> Cc: Rik van Riel <[email protected]> --- mm/vmscan.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 67c1950..95fd2c3 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -281,17 +281,22 @@ shrink_slab_node(struct shrink_control *shrinkctl, struct shrinker *shrinker, nr_pages_scanned, lru_pages, max_pass, delta, total_scan); - while (total_scan >= batch_size) { + while (total_scan > 0) { unsigned long ret; + unsigned long nr_to_scan = min(batch_size, total_scan); - shrinkctl->nr_to_scan = batch_size; + if (!shrinkctl->target_mem_cgroup && + total_scan < batch_size) + break; + + shrinkctl->nr_to_scan = nr_to_scan; ret = shrinker->scan_objects(shrinker, shrinkctl); if (ret == SHRINK_STOP) break; freed += ret; - count_vm_events(SLABS_SCANNED, batch_size); - total_scan -= batch_size; + count_vm_events(SLABS_SCANNED, nr_to_scan); + total_scan -= nr_to_scan; cond_resched(); } -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
