blk-wbt: allow reset of default latency through sysfs

[linux-2.6-block.git] / Documentation / block / queue-sysfs.txt

diff --git a/Documentation/block/queue-sysfs.txt b/Documentation/block/queue-sysfs.txt
index 14235e72a70274bc7fffeb15316cedcb0247431e..51642159aedbbc405d1bb90fa89402c2143f8310 100644 (file)
--- a/Documentation/block/queue-sysfs.txt
+++ b/Documentation/block/queue-sysfs.txt
@@ -188,7 +188,9 @@ wb_lat_usec (RW)
 If the device is registered for writeback throttling, then this file shows
 the target minimum read latency. If this latency is exceeded in a given
 window of time (see wb_window_usec), then the writeback throttling will start
-scaling back writes.
+scaling back writes. Writing a value of '0' to this file disables the
+feature. Writing a value of '-1' to this file resets the value to the
+default setting.
 
 
 Jens Axboe <jens.axboe@oracle.com>, February 2009