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authorJens Axboe <axboe@fb.com>2016-11-28 19:22:47 +0300
committerJens Axboe <axboe@fb.com>2016-11-28 20:27:03 +0300
commit80e091d10e8bf7b801d634ea8870b9e907314424 (patch)
tree05d99a001b158de7e3f6f9eb119f28bb226b8bc2 /Documentation
parentfeffa5cc7b47f38210d4997ceb3fe30881d6c337 (diff)
downloadlinux-80e091d10e8bf7b801d634ea8870b9e907314424.tar.xz
blk-wbt: allow reset of default latency through sysfs
Allow a write of '-1' to reset the default latency target for a given device. This removes knowledge of the different default settings for rotational vs non-rotational from user space. Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/block/queue-sysfs.txt4
1 files changed, 3 insertions, 1 deletions
diff --git a/Documentation/block/queue-sysfs.txt b/Documentation/block/queue-sysfs.txt
index 14235e72a702..51642159aedb 100644
--- 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