1 files changed, 6 insertions, 0 deletions

diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt
index 4bca2a3d9174..a46c10fcddfc 100644
--- a/Documentation/sysctl/vm.txt
+++ b/Documentation/sysctl/vm.txt
@@ -137,6 +137,7 @@ This is value ORed together of
 1       = Zone reclaim on
 2       = Zone reclaim writes dirty pages out
 4       = Zone reclaim swaps pages
+8       = Also do a global slab reclaim pass
 
 zone_reclaim_mode is set during bootup to 1 if it is determined that pages
 from remote zones will cause a measurable performance reduction. The
@@ -160,6 +161,11 @@ Allowing regular swap effectively restricts allocations to the local
 node unless explicitly overridden by memory policies or cpuset
 configurations.
 
+It may be advisable to allow slab reclaim if the system makes heavy
+use of files and builds up large slab caches. However, the slab
+shrink operation is global, may take a long time and free slabs
+in all nodes of the system.
+
 ================================================================
 
 zone_reclaim_interval: