.. option:: max_open_zones=int
- A zone of a zoned block device is in the open state when it is partially
- written (i.e. not all sectors of the zone have been written). Zoned
- block devices may have a limit on the total number of zones that can
- be simultaneously in the open state, that is, the number of zones that
- can be written to simultaneously. The :option:`max_open_zones` parameter
- limits the number of zones to which write commands are issued by all fio
- jobs, that is, limits the number of zones that will be in the open
- state. This parameter is relevant only if the :option:`zonemode` =zbd is
- used. The default value is always equal to maximum number of open zones
- of the target zoned block device and a value higher than this limit
- cannot be specified by users unless the option
- :option:`ignore_zone_limits` is specified. When
- :option:`ignore_zone_limits` is specified or the target device has no
- limit on the number of zones that can be in an open state,
- :option:`max_open_zones` can specify 0 to disable any limit on the
- number of zones that can be simultaneously written to by all jobs.
+ When a zone of a zoned block device is partially written (i.e. not all
+ sectors of the zone have been written), the zone is in one of three
+ conditions: 'implicit open', 'explicit open' or 'closed'. Zoned block
+ devices may have a limit called 'max_open_zones' (same name as the
+ parameter) on the total number of zones that can simultaneously be in
+ the 'implicit open' or 'explicit open' conditions. Zoned block devices
+ may have another limit called 'max_active_zones', on the total number of
+ zones that can simultaneously be in the three conditions. The
+ :option:`max_open_zones` parameter limits the number of zones to which
+ write commands are issued by all fio jobs, that is, limits the number of
+ zones that will be in the conditions. When the device has the
+ max_open_zones limit and does not have the max_active_zones limit, the
+ :option:`max_open_zones` parameter limits the number of zones in the two
+ open conditions up to the limit. In this case, fio includes zones in the
+ two open conditions to the write target zones at fio start. When the
+ device has both the max_open_zones and the max_active_zones limits, the
+ :option:`max_open_zones` parameter limits the number of zones in the
+ three conditions up to the limit. In this case, fio includes zones in
+ the three conditions to the write target zones at fio start.
+
+ This parameter is relevant only if the :option:`zonemode` =zbd is used.
+ The default value is always equal to the max_open_zones limit of the
+ target zoned block device and a value higher than this limit cannot be
+ specified by users unless the option :option:`ignore_zone_limits` is
+ specified. When :option:`ignore_zone_limits` is specified or the target
+ device does not have the max_open_zones limit, :option:`max_open_zones`
+ can specify 0 to disable any limit on the number of zones that can be
+ simultaneously written to by all jobs.
.. option:: job_max_open_zones=int
reads and writes. See :manpage:`ionice(1)`. See also the
:option:`prioclass` option.
+.. option:: cmdprio_hint=int[,int] : [io_uring] [libaio]
+
+ Set the I/O priority hint 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 (no hint). A single value applies to reads and
+ writes. Comma-separated values may be specified for reads and writes.
+ See also the :option:`priohint` option.
+
.. option:: cmdprio=int[,int] : [io_uring] [libaio]
Set the I/O priority value to use for I/Os that must be issued with
cmdprio_bssplit=blocksize/percentage:blocksize/percentage
- In this case, each entry will use the priority class and priority
- level defined by the options :option:`cmdprio_class` and
- :option:`cmdprio` respectively.
+ In this case, each entry will use the priority class, priority hint
+ and priority level defined by the options :option:`cmdprio_class`,
+ :option:`cmdprio` and :option:`cmdprio_hint` respectively.
The second accepted format for this option is:
accepted format does not restrict all entries to have the same priority
class and priority level.
- For both formats, only the read and write data directions are supported,
+ The third accepted format for this option is:
+
+ cmdprio_bssplit=blocksize/percentage/class/level/hint:...
+
+ This is an extension of the second accepted format that allows to also
+ specify a priority hint.
+
+ For all formats, only the read and write data directions are supported,
values for trim IOs are ignored. This option is mutually exclusive with
the :option:`cmdprio_percentage` option.
priority setting, see I/O engine specific :option:`cmdprio_percentage`
and :option:`cmdprio_class` options.
+.. option:: priohint=int
+
+ Set the I/O priority hint. This is only applicable to platforms that
+ support I/O priority classes and to devices with features controlled
+ through priority hints, e.g. block devices supporting command duration
+ limits, or CDL. CDL is a way to indicate the desired maximum latency
+ of I/Os so that the device can optimize its internal command scheduling
+ according to the latency limits indicated by the user.
+
+ For per-I/O priority hint setting, see the I/O engine specific
+ :option:`cmdprio_hint` option.
+
.. option:: cpus_allowed=str
Controls the same options as :option:`cpumask`, but accepts a textual
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