[PATCH] VM: rate limit early reclaim

When early zone reclaim is turned on the LRU is scanned more frequently when a
zone is low on memory.  This limits when the zone reclaim can be called by
skipping the scan if another thread (either via kswapd or sync reclaim) is
already reclaiming from the zone.

Signed-off-by: Martin Hicks <mort@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index dfc2452ccb10..18fed8b67943 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -149,6 +149,8 @@ struct zone {
          * as it fails a watermark_ok() in __alloc_pages?
          */
         int                     reclaim_pages;
+        /* A count of how many reclaimers are scanning this zone */
+        atomic_t                reclaim_in_progress;
 
         /*
          * prev_priority holds the scanning priority for this zone.  It is