Option for changing log files to use Unix epoch instead of being

[fio.git] / fio.1

diff --git a/fio.1 b/fio.1
index 0461d90e1f8ba6077fe38507021662f17c5f87ba..8d596fb19105df2e6b3aabcbda171cf462f3157e 100644 (file)
--- a/fio.1
+++ b/fio.1
@@ -656,7 +656,8 @@ and send/receive. This ioengine defines engine specific options.
 .TP
 .B cpuio
 Doesn't transfer any data, but burns CPU cycles according to \fBcpuload\fR and
-\fBcpuchunks\fR parameters.
+\fBcpuchunks\fR parameters. A job never finishes unless there is at least one
+non-cpuio job.
 .TP
 .B guasi
 The GUASI I/O engine is the Generic Userspace Asynchronous Syscall Interface
@@ -1245,6 +1246,9 @@ multiple times. Thus it will not work on eg network or splice IO.
 .BI unlink \fR=\fPbool
 Unlink job files when done.  Default: false.
 .TP
+.BI unlink_each_loop \fR=\fPbool
+Unlink job files after each iteration or loop.  Default: false.
+.TP
 .BI loops \fR=\fPint
 Specifies the number of iterations (runs of the same workload) of this job.
 Default: 1.
@@ -1475,6 +1479,14 @@ N is the number of jobs). Even if the filename is given, fio will still
 append the type of log. If \fBper_job_logs\fR is false, then the filename will
 not include the job index. See the \fBLOG FILE FORMATS\fR section.
 .TP
+.BI write_hist_log \fR=\fPstr
+Same as \fBwrite_lat_log\fR, 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 \fBper_job_logs\fR is false, then the filename will not
+include the job index. See the \fBLOG FILE FORMATS\fR section.
+.TP
 .BI write_iops_log \fR=\fPstr
 Same as \fBwrite_bw_log\fR, 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
@@ -1495,6 +1507,20 @@ If \fBlog_avg_msec\fR 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 logged.
 .TP
+.BI log_hist_msec \fR=\fPint
+Same as \fBlog_avg_msec\fR, but logs entries for completion latency histograms.
+Computing latency percentiles from averages of intervals using \fBlog_avg_msec\fR
+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 \fBlog_hist_coarseness\fR as well. Defaults
+to 0, meaning histogram logging is disabled.
+.TP
+.BI log_hist_coarseness \fR=\fPint
+Integer ranging from 0 to 6, defining the coarseness of the resolution of the
+histogram logs enabled with \fBlog_hist_msec\fR. For each increment in
+coarseness, fio outputs half as many bins. Defaults to 0, for which histogram
+logs contain 1216 latency bins. See the \fBLOG FILE FORMATS\fR section.
+.TP
 .BI log_offset \fR=\fPbool
 If this is set, the iolog options will include the byte offset for the IO
 entry as well as the other data values.
@@ -1520,6 +1546,11 @@ If set, fio will store the log files in a compressed format. They can be
 decompressed with fio, using the \fB\-\-inflate-log\fR command line parameter.
 The files will be stored with a \fB\.fz\fR suffix.
 .TP
+.BI log_unix_epoch \fR=\fPbool
+If set, fio will log Unix timestamps to the log files produced by enabling
+\fBwrite_type_log\fR for each log type, instead of the default zero-based
+timestamps.
+.TP
 .BI block_error_percentiles \fR=\fPbool
 If set, record errors in trim block-sized units from writes and trims and output
 a histogram of how many trims it took to get to errors, and what kind of error
@@ -1694,13 +1725,13 @@ Some parameters are only valid when a specific ioengine is in use. These are
 used identically to normal parameters, with the caveat that when used on the
 command line, they must come after the ioengine.
 .TP
-.BI (cpu)cpuload \fR=\fPint
+.BI (cpuio)cpuload \fR=\fPint
 Attempt to use the specified percentage of CPU cycles.
 .TP
-.BI (cpu)cpuchunks \fR=\fPint
+.BI (cpuio)cpuchunks \fR=\fPint
 Split the load into cycles of the given time. In microseconds.
 .TP
-.BI (cpu)exit_on_io_done \fR=\fPbool
+.BI (cpuio)exit_on_io_done \fR=\fPbool
 Detect when IO threads are done, then exit.
 .TP
 .BI (libaio)userspace_reap
@@ -2301,6 +2332,13 @@ they aren't applicable if windowed logging is enabled. If windowed logging
 is enabled and \fBlog_max_value\fR is set, then fio logs maximum values in
 that window instead of averages.
 
+For histogram logging the logs look like this:
+
+.B time (msec), data direction, block-size, bin 0, bin 1, ..., bin 1215
+
+Where 'bin i' gives the frequency of IO requests with a latency falling in
+the i-th bin. See \fBlog_hist_coarseness\fR for logging fewer bins.
+
 .RE
 
 .SH CLIENT / SERVER