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 :option:`prio` or :option:`prioclass` options. For this option
- to be effective, NCQ priority must be supported and enabled, and `direct=1'
+ values may be specified for reads and writes. 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.
+.. option:: cmdprio_class=int[,int] : [io_uring] [libaio]
+
+ Set the I/O priority class to use for I/Os that must be issued with
+ a priority when :option:`cmdprio_percentage` or
+ :option:`cmdprio_bssplit` is set. If not specified when
+ :option:`cmdprio_percentage` or :option:`cmdprio_bssplit` 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 :manpage:`ionice(1)`. See also the
+ :option:`prioclass` option.
+
+.. option:: cmdprio=int[,int] : [io_uring] [libaio]
+
+ Set the I/O priority value to use for I/Os that must be issued with
+ a priority when :option:`cmdprio_percentage` or
+ :option:`cmdprio_bssplit` is set. If not specified when
+ :option:`cmdprio_percentage` or :option:`cmdprio_bssplit` 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 :manpage:`ionice(1)`.
+ Refer to an appropriate manpage for other operating systems since
+ meaning of priority may differ. See also the :option:`prio` option.
+
+.. option:: cmdprio_bssplit=str[,str] : [io_uring] [libaio]
+ 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:`bssplit` option, 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
+ :option:`bssplit` option, with the exception that values for
+ trim IOs are ignored. This option is mutually exclusive with the
+ :option:`cmdprio_percentage` option.
+
.. option:: fixedbufs : [io_uring]
If fio is asked to do direct IO, then Linux will map pages for each
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
- :option:`thinktime_blocks` and :option:`thinktime_spin`.
+ :option:`thinktime_blocks`, :option:`thinktime_iotime` and :option:`thinktime_spin`.
.. option:: thinktime_spin=time
:option:`thinktime_blocks` blocks. If this is set to `issue`, then the trigger happens
at the issue side.
+.. option:: thinktime_iotime=time
+
+ Only valid if :option:`thinktime` is set - control :option:`thinktime`
+ interval by time. The :option:`thinktime` stall is repeated after IOs
+ are executed for :option:`thinktime_iotime`. 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,
+ :option:`thinktime_iotime` is interpreted as a number of seconds. If
+ this option is used together with :option:`thinktime_blocks`, the
+ :option:`thinktime` stall is repeated after :option:`thinktime_iotime`
+ or after :option:`thinktime_blocks` IOs, whichever happens first.
+
.. option:: rate=int[,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
:manpage:`ionice(1)`. Refer to an appropriate manpage for other operating
systems since meaning of priority may differ. For per-command priority
- setting, see I/O engine specific `cmdprio_percentage` option.
+ setting, see I/O engine specific :option:`cmdprio_percentage` and
+ :option:`cmdprio` options.
.. option:: prioclass=int
Set the I/O priority class. See man :manpage:`ionice(1)`. For per-command
- priority setting, see I/O engine specific `cmdprio_percentage` option.
+ priority setting, see I/O engine specific :option:`cmdprio_percentage`
+ and :option:`cmdprio_class` options.
.. option:: cpus_allowed=str
:option:`write_bw_log` for details about the filename format and `Log
File Formats`_ for how data is structured within the file.
+.. option:: log_entries=int
+
+ By default, fio will log an entry in the iops, latency, or bw log for
+ every I/O that completes. The initial number of I/O log entries is 1024.
+ When the log entries are all used, new log entries are dynamically
+ allocated. This dynamic log entry allocation may negatively impact
+ time-related statistics such as I/O tail latencies (e.g. 99.9th percentile
+ completion latency). This option allows specifying a larger initial
+ number of log entries to avoid run-time allocations of new log entries,
+ resulting in more precise time-related I/O statistics.
+ Also see :option:`log_avg_msec`. Defaults to 1024.
+
.. option:: log_avg_msec=int
By default, fio will log an entry in the iops, latency, or bw log for every
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