X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=HOWTO;h=5daaef032ceebb3bf5f2d0fc3bc7807258237fb3;hp=a7d6db4d84b6489380f2aff41f3ff6d8fc6b49a8;hb=16e56d250f72e4fec4591d562a5f4d7a16ba1bb8;hpb=769d13b5c5c4948c89311b55bce26cec4196e3d1

diff --git a/HOWTO b/HOWTO
index a7d6db4d..5daaef03 100644
--- a/HOWTO
+++ b/HOWTO
@@ -297,7 +297,7 @@ irange	Integer range with suffix. Allows value range to be given, such
 	1k:4k. If the option allows two sets of ranges, they can be
 	specified with a ',' or '/' delimiter: 1k-4k/8k-32k. Also see
 	int.
-float_list	A list of floating numbers, separated by a ':' character.
+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.
@@ -1214,8 +1214,47 @@ ramp_time=time	If set, fio will run the specified workload for this amount
 		thus it will increase the total runtime if a special timeout
 		or runtime is specified.
 
-invalidate=bool	Invalidate the buffer/page cache parts for this file prior
-		to starting io. Defaults to true.
+steadystate=str:float
+ss=str:float	Define the criterion and limit for assessing steady state
+		performance. The first parameter designates the criterion
+		whereas the second parameter sets the threshold. When the
+		criterion falls below the threshold for the specified duration,
+		the job will stop. For example, iops_slope:0.1% will direct fio
+		to terminate the job when the least squares regression slope
+		falls below 0.1% of the mean IOPS. If group_reporting is
+		enabled this will apply to all jobs in the group. Below is the
+		list of available steady state assessment criteria. All
+		assessments are carried out using only data from the rolling
+		collection window. Threshold limits can be expressed as a fixed
+		value or as a percentage of the mean in the collection window.
+			iops	Collect IOPS data. Stop the job if all
+				individual IOPS measurements are within the
+				specified limit of the mean IOPS (e.g., iops:2
+				means that all individual IOPS values must be
+				within 2 of the mean, whereas iops:0.2% means
+				that all individual IOPS values must be within
+				0.2% of	the mean IOPS to terminate the job).
+			iops_slope
+				Collect IOPS data and calculate the least
+				squares regression slope. Stop the job if the
+				slope falls below the specified limit.
+			bw	Collect bandwidth data. Stop the job if all
+				individual bandwidth measurements are within
+				the specified limit of the mean bandwidth.
+			bw_slope
+				Collect bandwidth data and calculate the least
+				squares regression slope. Stop the job if the
+				slope falls below the specified limit.
+
+steadystate_duration=time
+ss_dur=time	A rolling window of this duration will be used to judge whether
+		steady state has been reached. Data will be collected once per
+		second. The default is 0 which disables steady state detection.
+
+steadystate_ramp_time=time
+ss_ramp=time	Allow the job to run for the specified duration before
+		beginning data collection for checking the steady state job
+		termination criterion. The default is 0.
 
 sync=bool	Use sync io for buffered writes. For the majority of the
 		io engines, this means using O_SYNC.
@@ -1295,7 +1334,7 @@ iopsavgtime=int	Average the calculated IOPS over the given time. Value
 		through 'write_iops_log', then the minimum of this option and
 		'log_avg_msec' will be used.  Default: 500ms.
 
-create_serialize=bool	If true, serialize the file creating for the jobs.
+create_serialize=bool	If true, serialize the file creation for the jobs.
 			This may be handy to avoid interleaving of data
 			files, which may greatly depend on the filesystem
 			used and even the number of processors in the system.
@@ -1334,6 +1373,8 @@ unlink=bool	Unlink the job files when done. Not the default, as repeated
 		runs of that job would then waste time recreating the file
 		set again and again.
 
+unlink_each_loop=bool	Unlink job files after each iteration or loop.
+
 loops=int	Run the specified number of iterations of this job. Used
 		to repeat the same workload a given number of times. Defaults
 		to 1.
@@ -1606,10 +1647,18 @@ write_lat_log=str Same as write_bw_log, except that this option stores io
 		The actual log names will be foo_slat.x.log, foo_clat.x.log,
 		and foo_lat.x.log, where x is the index of the job (1..N,
 		where N is the number of jobs). This helps fio_generate_plot
-		fine the logs automatically. If 'per_job_logs' is false, then
+		find the logs automatically. If 'per_job_logs' is false, then
 		the filename will not include the job index. See 'Log File
 		Formats'.
 
+write_hist_log=str Same as write_lat_log, but writes I/O completion
+		latency histograms. If no filename is given with this option, the
+		default filename of "jobname_clat_hist.x.log" is used, where x is
+		the index of the job (1..N, where N is the number of jobs). Even
+		if the filename is given, fio will still append the type of log.
+		If per_job_logs is false, then the filename will not include the
+		job index. See 'Log File Formats'.
+
 write_iops_log=str Same as write_bw_log, but writes IOPS. If no filename is
 		given with this option, the default filename of
 		"jobname_type.x.log" is used,where x is the index of the job
@@ -1625,6 +1674,20 @@ log_avg_msec=int By default, fio will log an entry in the iops, latency,
 		specified period of time, reducing the resolution of the log.
 		See log_max_value as well. Defaults to 0, logging all entries.
 
+log_hist_msec=int Same as log_avg_msec, but logs entries for completion
+		latency histograms. Computing latency percentiles from averages of
+		intervals using log_avg_msec is innacurate. Setting this option makes
+		fio log histogram entries over the specified period of time, reducing
+		log sizes for high IOPS devices while retaining percentile accuracy.
+		See log_hist_coarseness as well. Defaults to 0, meaning histogram
+		logging is disabled.
+
+log_hist_coarseness=int Integer ranging from 0 to 6, defining the coarseness
+		of the resolution of the histogram logs enabled with log_hist_msec. For
+		each increment in coarseness, fio outputs half as many bins. Defaults to
+		0, for which histogram logs contain 1216 latency bins. See
+		'Log File Formats'.
+
 log_max_value=bool	If log_avg_msec is set, fio logs the average over that
 		window. If you instead want to log the maximum value, set this
 		option to 1. Defaults to 0, meaning that averaged values are