engines/libzbc: enable block backend

[fio.git] / fio.1

diff --git a/fio.1 b/fio.1
index b29ac43759cdd2ac16e4620986ba2ec3aac5f7b5..aa248a3b6da62172a2ee0a27e5b345034ebfe7fd 100644 (file)
--- a/fio.1
+++ b/fio.1
@@ -1132,7 +1132,7 @@ first. This may interfere with a given rate setting, if fio is asked to
 limit reads or writes to a certain rate. If that is the case, then the
 distribution may be skewed. Default: 50.
 .TP
 limit reads or writes to a certain rate. If that is the case, then the
 distribution may be skewed. Default: 50.
 .TP

-.BI random_distribution \fR=\fPstr:float[,str:float][,str:float]
+.BI random_distribution \fR=\fPstr:float[:float][,str:float][,str:float]

 By default, fio will use a completely uniform random distribution when asked
 to perform random I/O. Sometimes it is useful to skew the distribution in
 specific ways, ensuring that some parts of the data is more hot than others.
 By default, fio will use a completely uniform random distribution when asked
 to perform random I/O. Sometimes it is useful to skew the distribution in
 specific ways, ensuring that some parts of the data is more hot than others.


@@ -1168,6 +1168,14 @@ option. If a non\-uniform model is used, fio will disable use of the random
 map. For the \fBnormal\fR distribution, a normal (Gaussian) deviation is
 supplied as a value between 0 and 100.
 .P
 map. For the \fBnormal\fR distribution, a normal (Gaussian) deviation is
 supplied as a value between 0 and 100.
 .P

+The second, optional float is allowed for \fBpareto\fR, \fBzipf\fR and \fBnormal\fR
+distributions. It allows to set base of distribution in non-default place, giving
+more control over most probable outcome. This value is in range [0-1] which maps linearly to
+range of possible random values.
+Defaults are: random for \fBpareto\fR and \fBzipf\fR, and 0.5 for \fBnormal\fR.
+If you wanted to use \fBzipf\fR with a `theta` of 1.2 centered on 1/4 of allowed value range,
+you would use `random_distibution=zipf:1.2:0.25`.
+.P

 For a \fBzoned\fR distribution, fio supports specifying percentages of I/O
 access that should fall within what range of the file or device. For
 example, given a criteria of:
 For a \fBzoned\fR distribution, fio supports specifying percentages of I/O
 access that should fall within what range of the file or device. For
 example, given a criteria of:


@@ -1690,12 +1698,21 @@ This engine defines engine specific options.
 .TP
 .B cpuio
 Doesn't transfer any data, but burns CPU cycles according to the
 .TP
 .B cpuio
 Doesn't transfer any data, but burns CPU cycles according to the

-\fBcpuload\fR and \fBcpuchunks\fR options. Setting
-\fBcpuload\fR\=85 will cause that job to do nothing but burn 85%
-of the CPU. In case of SMP machines, use `numjobs=<nr_of_cpu>'
-to get desired CPU usage, as the cpuload only loads a
-single CPU at the desired rate. A job never finishes unless there is
-at least one non-cpuio job.
+\fBcpuload\fR, \fBcpuchunks\fR and \fBcpumode\fR options.
+A job never finishes unless there is at least one non-cpuio job.
+.RS
+.P
+.PD 0
+\fBcpuload\fR\=85 will cause that job to do nothing but burn 85% of the CPU.
+In case of SMP machines, use \fBnumjobs=<nr_of_cpu>\fR\ to get desired CPU usage,
+as the cpuload only loads a single CPU at the desired rate.
+
+.P
+\fBcpumode\fR\=qsort replace the default noop instructions loop
+by a qsort algorithm to consume more energy.
+
+.P
+.RE

 .TP
 .B rdma
 The RDMA I/O engine supports both RDMA memory semantics
 .TP
 .B rdma
 The RDMA I/O engine supports both RDMA memory semantics


@@ -2097,6 +2114,16 @@ client and the server or in certain loopback configurations.
 Specify stat system call type to measure lookup/getattr performance.
 Default is \fBstat\fR for \fBstat\fR\|(2).
 .TP
 Specify stat system call type to measure lookup/getattr performance.
 Default is \fBstat\fR for \fBstat\fR\|(2).
 .TP

+.BI (sg)hipri
+If this option is set, fio will attempt to use polled IO completions. This
+will have a similar effect as (io_uring)hipri. Only SCSI READ and WRITE
+commands will have the SGV4_FLAG_HIPRI set (not UNMAP (trim) nor VERIFY).
+Older versions of the Linux sg driver that do not support hipri will simply
+ignore this flag and do normal IO. The Linux SCSI Low Level Driver (LLD)
+that "owns" the device also needs to support hipri (also known as iopoll
+and mq_poll). The MegaRAID driver is an example of a SCSI LLD.
+Default: clear (0) which does normal (interrupted based) IO.
+.TP

 .BI (sg)readfua \fR=\fPbool
 With readfua option set to 1, read operations include the force
 unit access (fua) flag. Default: 0.
 .BI (sg)readfua \fR=\fPbool
 With readfua option set to 1, read operations include the force
 unit access (fua) flag. Default: 0.


@@ -2296,6 +2323,12 @@ queue depth setting redundant, since no more than 1 I/O will be queued
 before we have to complete it and do our \fBthinktime\fR. In other words, this
 setting effectively caps the queue depth if the latter is larger.
 .TP
 before we have to complete it and do our \fBthinktime\fR. In other words, this
 setting effectively caps the queue depth if the latter is larger.
 .TP

+.BI thinktime_blocks_type \fR=\fPstr
+Only valid if \fBthinktime\fR is set - control how \fBthinktime_blocks\fR triggers.
+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 rate \fR=\fPint[,int][,int]
 Cap the bandwidth used by this job. The number is in bytes/sec, the normal
 suffix rules apply. Comma-separated values may be specified for reads,
 .BI rate \fR=\fPint[,int][,int]
 Cap the bandwidth used by this job. The number is in bytes/sec, the normal
 suffix rules apply. Comma-separated values may be specified for reads,