X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=HOWTO;h=3a02cc69aea4a83860612e3bc3d7d99c6ad9b2b4;hp=f62a517004a1dfff3e049e544299b4a2cccad5bf;hb=f5c3bcf2fd64d2e3e0869346a34e6627f177076f;hpb=25cd4b951d33ca9d42dfeda0937481d156ae1727

diff --git a/HOWTO b/HOWTO
index f62a5170..3a02cc69 100644
--- a/HOWTO
+++ b/HOWTO
@@ -576,6 +576,8 @@ Parameter types
 **float_list**
 	A list of floating point numbers, separated by a ':' character.
 
+With the above in mind, here follows the complete list of fio job parameters.
+
 
 Units
 ~~~~~
@@ -622,9 +624,6 @@ Units
 		Bit based.
 
 
-With the above in mind, here follows the complete list of fio job parameters.
-
-
 Job description
 ~~~~~~~~~~~~~~~
 
@@ -1015,8 +1014,8 @@ I/O type
 
 	``sequential`` is only useful for random I/O, where fio would normally
 	generate a new random offset for every I/O. If you append e.g. 8 to randread,
-	you would get a new random offset for every 8 I/O's. The result would be a
-	seek for only every 8 I/O's, instead of for every I/O. Use ``rw=randread:8``
+	you would get a new random offset for every 8 I/Os. The result would be a
+	seek for only every 8 I/Os, instead of for every I/O. Use ``rw=randread:8``
 	to specify that. As sequential I/O is already sequential, setting
 	``sequential`` for that would not result in any differences.  ``identical``
 	behaves in a similar fashion, except it sends the same offset 8 number of
@@ -1819,6 +1818,11 @@ caveat that when used on the command line, they must come after the
 	Set RWF_HIPRI on I/O, indicating to the kernel that it's of higher priority
 	than normal.
 
+.. option:: hipri_percentage : [pvsync2]
+
+	When hipri is set this determines the probability of a pvsync2 IO being high
+	priority. The default is 100%.
+
 .. option:: cpuload=int : [cpuio]
 
 	Attempt to use the specified percentage of CPU cycles. This is a mandatory
@@ -2590,7 +2594,7 @@ Verification
 
 .. option:: trim_backlog=int
 
-	Verify that trim/discarded blocks are returned as zeros.
+	Trim after this number of blocks are written.
 
 .. option:: trim_backlog_batch=int
 
@@ -2761,7 +2765,8 @@ Measurements and reporting
 .. option:: log_offset=int
 
 	If this is set, the iolog options will include the byte offset for the I/O
-	entry as well as the other data values.
+	entry as well as the other data values. Defaults to 0 meaning that
+	offsets are not present in logs. Also see `Log File Formats`_.
 
 .. option:: log_compression=int
 
@@ -3242,7 +3247,7 @@ numbers denote:
 **ios**
 		Number of I/Os performed by all groups.
 **merge**
-		Number of merges I/O the I/O scheduler.
+		Number of merges performed by the I/O scheduler.
 **ticks**
 		Number of ticks we kept the disk busy.
 **in_queue**
@@ -3278,7 +3283,7 @@ changed for some reason, this number will be incremented by 1 to signify that
 change.
 
 Split up, the format is as follows (comments in brackets denote when a
-field was introduced or whether its specific to some terse version):
+field was introduced or whether it's specific to some terse version):
 
     ::
 
@@ -3531,9 +3536,10 @@ Log File Formats
 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*, *offset*
+    *time* (`msec`), *value*, *data direction*, *block size* (`bytes`),
+    *offset* (`bytes`)
 
-Time for the log entry is always in milliseconds. The *value* logged depends
+*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:
 
     **Latency log**
@@ -3552,16 +3558,17 @@ on the type of log, it will be one of the following:
 	**2**
 		I/O is a TRIM
 
-The *offset* is the offset, in bytes, from the start of the file, for that
-particular I/O. The logging of the offset can be toggled with
-:option:`log_offset`.
+The entry's *block size* is always in bytes. The *offset* is the offset, in bytes,
+from the start of the file, for that particular I/O. The logging of the offset can be
+toggled with :option:`log_offset`.
 
 Fio defaults to logging every individual I/O.  When IOPS are logged for individual
-I/Os the value entry will always be 1.  If windowed logging is enabled through
+I/Os the *value* entry will always be 1. If windowed logging is enabled through
 :option:`log_avg_msec`, fio logs the average values over the specified period of time.
 If windowed logging is enabled and :option:`log_max_value` is set, then fio logs
-maximum values in that window instead of averages.  Since 'data direction' and
-'offset' are per-I/O values, they aren't applicable if windowed logging is enabled.
+maximum values in that window instead of averages. Since *data direction*, *block
+size* and *offset* are per-I/O values, if windowed logging is enabled they
+aren't applicable and will be 0.
 
 Client/Server
 -------------