Priority bit log file format documentation update

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index 9e339bb8d0a608a2f83b141197bd1bbbb503804b..8cf8d6506b219e0f9933813616a7d682218adb24 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -4165,7 +4165,7 @@ Fio supports a variety of log file formats, for logging latencies, bandwidth,
 and IOPS. The logs share a common format, which looks like this:
 
     *time* (`msec`), *value*, *data direction*, *block size* (`bytes`),
-    *offset* (`bytes`)
+    *offset* (`bytes`), *command priority*
 
 *Time* for the log entry is always in milliseconds. The *value* logged depends
 on the type of log, it will be one of the following:
@@ -4190,6 +4190,9 @@ The entry's *block size* is always in bytes. The *offset* is the position in byt
 from the start of the file for that particular I/O. The logging of the offset can be
 toggled with :option:`log_offset`.
 
+*Command priority* is 0 for normal priority and 1 for high priority. This is controlled
+by the ioengine specific :option:`cmdprio_percentage`.
+
 Fio defaults to logging every individual I/O but when windowed logging is set
 through :option:`log_avg_msec`, either the average (by default) or the maximum
 (:option:`log_max_value` is set) *value* seen over the specified period of time