doc: Add release note for mclock scheduler refinements and profiles

Signed-off-by: Sridhar Seshasayee <sseshasa@redhat.com>

diff --git a/doc/releases/pacific.rst b/doc/releases/pacific.rst
index c1eec7acabf90222f245aae346755ecd2463c825..7a890a454a82d6cf9027bf1fbdb2cae97a2c4e1d 100644 (file)
--- a/doc/releases/pacific.rst
+++ b/doc/releases/pacific.rst
@@ -84,4 +84,12 @@ Notable Changes
   is enabled. This helps with the monitor logs on larger clusters, that may get
   many 'osd.X reported immediately failed by osd.Y' messages, and confuse tools.
 
+* The mclock scheduler has been refined. A set of built-in profiles are now available that
+  provide QoS between the internal and external clients of Ceph. To enable the mclock
+  scheduler, set the config option "osd_op_queue" to "mclock_scheduler". The
+  "high_client_ops" profile is enabled by default, and allocates more OSD bandwidth to
+  external client operations than to internal client operations (such as background recovery
+  and scrubs). Other built-in profiles include "high_recovery_ops" and "balanced". These
+  built-in profiles optimize the QoS provided to clients of mclock scheduler.
+