1 files changed, 6 insertions, 0 deletions

diff --git a/Documentation/cpusets.txt b/Documentation/cpusets.txt
index 159e2a0c3e80..842f0d1ab216 100644
--- a/Documentation/cpusets.txt
+++ b/Documentation/cpusets.txt
@@ -217,6 +217,12 @@ exclusive cpuset.  Also, the use of a Linux virtual file system (vfs)
 to represent the cpuset hierarchy provides for a familiar permission
 and name space for cpusets, with a minimum of additional kernel code.
 
+The cpus and mems files in the root (top_cpuset) cpuset are
+read-only.  The cpus file automatically tracks the value of
+cpu_online_map using a CPU hotplug notifier, and the mems file
+automatically tracks the value of node_online_map using the
+cpuset_track_online_nodes() hook.
+
 
 1.4 What are exclusive cpusets ?
 --------------------------------