with the caveat that when used on the command line, they must come after the
\fBioengine\fR that defines them is selected.
.TP
-.BI (io_uring,libaio)cmdprio_percentage \fR=\fPint
-Set the percentage of I/O that will be issued with higher priority by setting
-the priority bit. Non-read I/O is likely unaffected by ``cmdprio_percentage``.
-This option cannot be used with the `prio` or `prioclass` options. For this
-option to set the priority bit properly, NCQ priority must be supported and
-enabled and `direct=1' option must be used. fio must also be run as the root
-user.
+.BI (io_uring,libaio)cmdprio_percentage \fR=\fPint[,int]
+Set the percentage of I/O that will be issued with the highest priority.
+Default: 0. A single value applies to reads and writes. Comma-separated
+values may be specified for reads and writes. This option cannot be used
+with the `prio` or `prioclass` options. For this option to be effective,
+NCQ priority must be supported and enabled, and `direct=1' option must be
+used. fio must also be run as the root user.
+.TP
+.BI (io_uring,libaio)cmdprio_class \fR=\fPint[,int]
+Set the I/O priority class to use for I/Os that must be issued with a
+priority when \fBcmdprio_percentage\fR or \fBcmdprio_bssplit\fR is set.
+If not specified when \fBcmdprio_percentage\fR or \fBcmdprio_bssplit\fR
+is set, this defaults to the highest priority class. A single value applies
+to reads and writes. Comma-separated values may be specified for reads and
+writes. See man \fBionice\fR\|(1). See also the \fBprioclass\fR option.
+.TP
+.BI (io_uring,libaio)cmdprio \fR=\fPint[,int]
+Set the I/O priority value to use for I/Os that must be issued with a
+priority when \fBcmdprio_percentage\fR or \fBcmdprio_bssplit\fR is set.
+If not specified when \fBcmdprio_percentage\fR or \fBcmdprio_bssplit\fR
+is set, this defaults to 0. Linux limits us to a positive value between
+0 and 7, with 0 being the highest. A single value applies to reads and writes.
+Comma-separated values may be specified for reads and writes. See man
+\fBionice\fR\|(1). Refer to an appropriate manpage for other operating systems
+since the meaning of priority may differ. See also the \fBprio\fR option.
+.TP
+.BI (io_uring,libaio)cmdprio_bssplit \fR=\fPstr[,str]
+To get a finer control over I/O priority, this option allows specifying
+the percentage of IOs that must have a priority set depending on the block
+size of the IO. This option is useful only when used together with the option
+\fBbssplit\fR, that is, multiple different block sizes are used for reads and
+writes. The format for this option is the same as the format of the
+\fBbssplit\fR option, with the exception that values for trim IOs are
+ignored. This option is mutually exclusive with the \fBcmdprio_percentage\fR
+option.
.TP
.BI (io_uring)fixedbufs
If fio is asked to do direct IO, then Linux will map pages for each IO call, and
Stall the job for the specified period of time after an I/O has completed before issuing the
next. May be used to simulate processing being done by an application.
When the unit is omitted, the value is interpreted in microseconds. See
-\fBthinktime_blocks\fR and \fBthinktime_spin\fR.
+\fBthinktime_blocks\fR, \fBthinktime_iotime\fR and \fBthinktime_spin\fR.
.TP
.BI thinktime_spin \fR=\fPtime
Only valid if \fBthinktime\fR is set - pretend to spend CPU time doing
The default is `complete', which triggers \fBthinktime\fR when fio completes
\fBthinktime_blocks\fR blocks. If this is set to `issue', then the trigger happens
at the issue side.
+.TP
+.BI thinktime_iotime \fR=\fPtime
+Only valid if \fBthinktime\fR is set - control \fBthinktime\fR interval by time.
+The \fBthinktime\fR stall is repeated after IOs are executed for
+\fBthinktime_iotime\fR. For example, `\-\-thinktime_iotime=9s \-\-thinktime=1s'
+repeat 10-second cycle with IOs for 9 seconds and stall for 1 second. When the
+unit is omitted, \fBthinktime_iotime\fR is interpreted as a number of seconds.
+If this option is used together with \fBthinktime_blocks\fR, the \fBthinktime\fR
+stall is repeated after \fBthinktime_iotime\fR or after \fBthinktime_blocks\fR
+IOs, whichever happens first.
+
.TP
.BI rate \fR=\fPint[,int][,int]
Cap the bandwidth used by this job. The number is in bytes/sec, the normal
between 0 and 7, with 0 being the highest. See man
\fBionice\fR\|(1). Refer to an appropriate manpage for other operating
systems since meaning of priority may differ. For per-command priority
-setting, see the I/O engine specific `cmdprio_percentage` option.
+setting, see the I/O engine specific `cmdprio_percentage` and
+`cmdprio` options.
.TP
.BI prioclass \fR=\fPint
Set the I/O priority class. See man \fBionice\fR\|(1). For per-command
-priority setting, see the I/O engine specific `cmdprio_percentage` option.
+priority setting, see the I/O engine specific `cmdprio_percentage` and
+`cmdprio_class` options.
.TP
.BI cpus_allowed \fR=\fPstr
Controls the same options as \fBcpumask\fR, but accepts a textual
entry as well as the other data values. Defaults to 0 meaning that
offsets are not present in logs. Also see \fBLOG FILE FORMATS\fR section.
.TP
+.BI log_prio \fR=\fPbool
+If this is set, the iolog options will include the I/O priority for the I/O
+entry as well as the other data values. Defaults to 0 meaning that
+I/O priorities are not present in logs. Also see \fBLOG FILE FORMATS\fR section.
+.TP
.BI log_compression \fR=\fPint
If this is set, fio will compress the I/O logs as it goes, to keep the
memory footprint lower. When a log reaches the specified size, that chunk is
from the start of the file for that particular I/O. The logging of the offset can be
toggled with \fBlog_offset\fR.
.P
-`Command priority` is 0 for normal priority and 1 for high priority. This is controlled
-by the ioengine specific \fBcmdprio_percentage\fR.
+If \fBlog_prio\fR is not set, the entry's `Command priority` is 1 for an IO executed
+with the highest RT priority class (\fBprioclass\fR=1 or \fBcmdprio_class\fR=1) and 0
+otherwise. This is controlled by the \fBprioclass\fR option and the ioengine specific
+\fBcmdprio_percentage\fR \fBcmdprio_class\fR options. If \fBlog_prio\fR is set, the
+entry's `Command priority` is the priority set for the IO, as a 16-bits hexadecimal
+number with the lowest 13 bits indicating the priority value (\fBprio\fR and
+\fBcmdprio\fR options) and the highest 3 bits indicating the IO priority class
+(\fBprioclass\fR and \fBcmdprio_class\fR options).
.P
Fio defaults to logging every individual I/O but when windowed logging is set
through \fBlog_avg_msec\fR, either the average (by default) or the maximum
projects / fio.git / blobdiff