X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=HOWTO;h=5bf71252fc12be09121b4c065cd47b0994f0ab29;hp=ca1542d5fdf88b7fa0e6e607ab019a98c5d2d770;hb=d2c87a78b4d73911982b8a691f8c07ff9afc5119;hpb=38f8c3180719acf17554eb330319326958d32e21

diff --git a/HOWTO b/HOWTO
index ca1542d5..5bf71252 100644
--- a/HOWTO
+++ b/HOWTO
@@ -757,7 +757,8 @@ ioengine=str	Defines how the job issues io to the file. The following
 				85% of the CPU. In case of SMP machines,
 				use numjobs=<no_of_cpu> to get desired CPU
 				usage, as the cpuload only loads a single
-				CPU at the desired rate.
+				CPU at the desired rate. A job never finishes
+				unless there is at least one non-cpuio job.
 
 			guasi	The GUASI IO engine is the Generic Userspace
 				Asyncronous Syscall Interface approach
@@ -1174,7 +1175,7 @@ cpus_allowed_policy=str Set the policy of how fio distributes the CPUs
 		one cpu per job. If not enough CPUs are given for the jobs
 		listed, then fio will roundrobin the CPUs in the set.
 
-numa_cpu_nodes=str Set this job running on spcified NUMA nodes' CPUs. The
+numa_cpu_nodes=str Set this job running on specified NUMA nodes' CPUs. The
 		arguments allow comma delimited list of cpu numbers,
 		A-B ranges, or 'all'. Note, to enable numa options support,
 		fio must be built on a system with libnuma-dev(el) installed.
@@ -1294,7 +1295,7 @@ 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.
@@ -1333,6 +1334,8 @@ 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.
@@ -1605,10 +1608,18 @@ 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
@@ -1624,6 +1635,20 @@ 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
@@ -1839,12 +1864,12 @@ that defines them is selected.
 [psyncv2] hipri		Set RWF_HIPRI on IO, indicating to the kernel that
 			it's of higher priority than normal.
 
-[cpu] cpuload=int Attempt to use the specified percentage of CPU cycles.
+[cpuio] cpuload=int Attempt to use the specified percentage of CPU cycles.
 
-[cpu] cpuchunks=int Split the load into cycles of the given time. In
+[cpuio] cpuchunks=int Split the load into cycles of the given time. In
 		microseconds.
 
-[cpu] exit_on_io_done=bool Detect when IO threads are done, then exit.
+[cpuio] exit_on_io_done=bool Detect when IO threads are done, then exit.
 
 [netsplice] hostname=str
 [net] hostname=str The host name or IP address to use for TCP or UDP based IO.