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Diffstat (limited to 'Documentation/block/queue-sysfs.txt')
| -rw-r--r-- | Documentation/block/queue-sysfs.txt | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/Documentation/block/queue-sysfs.txt b/Documentation/block/queue-sysfs.txt index 2a3904030..2847219eb 100644 --- a/Documentation/block/queue-sysfs.txt +++ b/Documentation/block/queue-sysfs.txt @@ -169,5 +169,18 @@ This is the number of bytes the device can write in a single write-same command. A value of '0' means write-same is not supported by this device. +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. + +wb_window_usec (RW) +------------------- +If the device is registered for writeback throttling, then this file shows +the value of the monitoring window in which we'll look at the target +latency. See wb_lat_usec. + Jens Axboe <jens.axboe@oracle.com>, February 2009 |