X-Git-Url: https://git.kernel.dk/?a=blobdiff_plain;f=fio.1;h=f134e0bf88ca9f958f1e8bdec594f3551e1ceb9d;hb=1e7fa601e884ec37014cfaecab3d4b587f0dd395;hp=a2379f9816c2b0103191ff15338d9180527bf896;hpb=56a1932582ca46e2d23fdc60bb39508797c797f2;p=fio.git

diff --git a/fio.1 b/fio.1
index a2379f98..f134e0bf 100644
--- a/fio.1
+++ b/fio.1
@@ -804,7 +804,11 @@ so. Default: false.
 When running a random write test across an entire drive many more zones will be
 open than in a typical application workload. Hence this command line option
 that allows to limit the number of open zones. The number of open zones is
-defined as the number of zones to which write commands are issued.
+defined as the number of zones to which write commands are issued by all
+threads/processes.
+.TP
+.BI job_max_open_zones \fR=\fPint
+Limit on the number of simultaneously opened zones per single thread/process.
 .TP
 .BI zone_reset_threshold \fR=\fPfloat
 A number between zero and one that indicates the ratio of logical blocks with
@@ -1806,7 +1810,8 @@ 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.
+enabled and `direct=1' option must be used. fio must also be run as the root
+user.
 .TP
 .BI (io_uring)fixedbufs
 If fio is asked to do direct IO, then Linux will map pages for each IO call, and
@@ -1852,6 +1857,22 @@ than normal.
 When hipri is set this determines the probability of a pvsync2 I/O being high
 priority. The default is 100%.
 .TP
+.BI (pvsync2,libaio,io_uring)nowait
+By default if a request cannot be executed immediately (e.g. resource starvation,
+waiting on locks) it is queued and the initiating process will be blocked until
+the required resource becomes free.
+This option sets the RWF_NOWAIT flag (supported from the 4.14 Linux kernel) and
+the call will return instantly with EAGAIN or a partial result rather than waiting.
+
+It is useful to also use \fBignore_error\fR=EAGAIN when using this option.
+Note: glibc 2.27, 2.28 have a bug in syscall wrappers preadv2, pwritev2.
+They return EOPNOTSUP instead of EAGAIN.
+
+For cached I/O, using this option usually means a request operates only with
+cached data. Currently the RWF_NOWAIT flag does not supported for cached write.
+For direct I/O, requests will only succeed if cache invalidation isn't required,
+file blocks are fully allocated and the disk request could be issued immediately.
+.TP
 .BI (cpuio)cpuload \fR=\fPint
 Attempt to use the specified percentage of CPU cycles. This is a mandatory
 option when using cpuio I/O engine.
@@ -2275,6 +2296,11 @@ The percentage of I/Os that must fall within the criteria specified by
 defaults to 100.0, meaning that all I/Os must be equal or below to the value
 set by \fBlatency_target\fR.
 .TP
+.BI latency_run \fR=\fPbool
+Used with \fBlatency_target\fR. If false (default), fio will find the highest
+queue depth that meets \fBlatency_target\fR and exit. If true, fio will continue
+running and try to meet \fBlatency_target\fR by adjusting queue depth.
+.TP
 .BI max_latency \fR=\fPtime
 If set, fio will exit the job with an ETIMEDOUT error if it exceeds this
 maximum latency. When the unit is omitted, the value is interpreted in
@@ -3837,7 +3863,8 @@ Fio supports a variety of log file formats, for logging latencies, bandwidth,
 and IOPS. The logs share a common format, which looks like this:
 .RS
 .P
-time (msec), value, data direction, block size (bytes), offset (bytes)
+time (msec), value, data direction, block size (bytes), offset (bytes),
+command priority
 .RE
 .P
 `Time' for the log entry is always in milliseconds. The `value' logged depends
@@ -3871,6 +3898,9 @@ The entry's `block size' is always in bytes. The `offset' is the position in byt
 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.
+.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
 (\fBlog_max_value\fR is set) `value' seen over the specified period of time