\fBfilesize\fR so that all the accounting still occurs, but no actual I/O will be
done other than creating the file.
.TP
+.B filestat
+Simply do stat() and do no I/O to the file. You need to set 'filesize'
+and 'nrfiles', so that files will be created.
+This engine is to measure file lookup and meta data access.
+.TP
.B libpmem
Read and write using mmap I/O to a file on a filesystem
mounted with DAX on a persistent memory device through the PMDK
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)hipri
-If this option is set, fio will attempt to use polled IO completions. Normal IO
-completions generate interrupts to signal the completion of IO, polled
-completions do not. Hence they are require active reaping by the application.
-The benefits are more efficient IO for high IOPS scenarios, and lower latencies
-for low queue depth IO.
+.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.
.TP
.BI (io_uring)fixedbufs
If fio is asked to do direct IO, then Linux will map pages for each IO call, and
before IO is started. This eliminates the need to map and release for each IO.
This is more efficient, and reduces the IO latency as well.
.TP
+.BI (io_uring)hipri
+If this option is set, fio will attempt to use polled IO completions. Normal IO
+completions generate interrupts to signal the completion of IO, polled
+completions do not. Hence they are require active reaping by the application.
+The benefits are more efficient IO for high IOPS scenarios, and lower latencies
+for low queue depth IO.
+.TP
.BI (io_uring)registerfiles
With this option, fio registers the set of files being used with the kernel.
This avoids the overhead of managing file counts in the kernel, making the
function. This can be useful when multiple paths exist between the
client and the server or in certain loopback configurations.
.TP
+.BI (filestat)stat_type \fR=\fPstr
+Specify stat system call type to measure lookup/getattr performance.
+Default is \fBstat\fR for \fBstat\fR\|(2).
+.TP
.BI (sg)readfua \fR=\fPbool
With readfua option set to 1, read operations include the force
unit access (fua) flag. Default: 0.
Set the I/O priority value of this job. Linux limits us to a positive value
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.
+systems since meaning of priority may differ. For per-command priority
+setting, see I/O engine specific `cmdprio_percentage` and `hipri_percentage`
+options.
.TP
.BI prioclass \fR=\fPint
-Set the I/O priority class. See man \fBionice\fR\|(1).
+Set the I/O priority class. See man \fBionice\fR\|(1). For per-command
+priority setting, see I/O engine specific `cmdprio_percentage` and `hipri_percent`
+options.
.TP
.BI cpus_allowed \fR=\fPstr
Controls the same options as \fBcpumask\fR, but accepts a textual
Disable measurements of throughput/bandwidth numbers. See
\fBdisable_lat\fR.
.TP
+.BI slat_percentiles \fR=\fPbool
+Report submission latency percentiles. Submission latency is not recorded
+for synchronous ioengines.
+.TP
.BI clat_percentiles \fR=\fPbool
-Enable the reporting of percentiles of completion latencies. This option is
-mutually exclusive with \fBlat_percentiles\fR.
+Report completion latency percentiles.
.TP
.BI lat_percentiles \fR=\fPbool
-Enable the reporting of percentiles of I/O latencies. This is similar to
-\fBclat_percentiles\fR, except that this includes the submission latency.
-This option is mutually exclusive with \fBclat_percentiles\fR.
+Report total latency percentiles. Total latency is the sum of submission
+latency and completion latency.
.TP
.BI percentile_list \fR=\fPfloat_list
-Overwrite the default list of percentiles for completion latencies and the
-block error histogram. Each number is a floating number in the range
+Overwrite the default list of percentiles for latencies and the
+block error histogram. Each number is a floating point number in the range
(0,100], and the maximum length of the list is 20. Use ':' to separate the
-numbers, and list the numbers in ascending order. For example,
-`\-\-percentile_list=99.5:99.9' will cause fio to report the values of
-completion latency below which 99.5% and 99.9% of the observed latencies
-fell, respectively.
+numbers. For example, `\-\-percentile_list=99.5:99.9' will cause fio to
+report the latency durations below which 99.5% and 99.9% of the observed
+latencies fell, respectively.
.TP
.BI significant_figures \fR=\fPint
If using \fB\-\-output\-format\fR of `normal', set the significant figures
projects / fio.git / blobdiff