Update HOWTO and man page for thinktime blocks impact on queue depth

[fio.git] / fio.1

diff --git a/fio.1 b/fio.1
index 401d9566632b9ca47944c98e3e81ede8fac982fd..91020b2eeb89a4b5b3d4da3f9ff7f2aa87f668c0 100644 (file)
--- a/fio.1
+++ b/fio.1
@@ -448,6 +448,9 @@ Basic \fIpread\fR\|(2) or \fIpwrite\fR\|(2) I/O.
 Basic \fIreadv\fR\|(2) or \fIwritev\fR\|(2) I/O. Will emulate queuing by
 coalescing adjacents IOs into a single submission.
 .TP
+.B pvsync
+Basic \fIpreadv\fR\|(2) or \fIpwritev\fR\|(2) I/O.
+.TP
 .B libaio
 Linux native asynchronous I/O. This ioengine defines engine specific options.
 .TP
@@ -641,6 +644,15 @@ If you wanted to use zipf with a theta of 1.2, you would use
 random_distribution=zipf:1.2 as the option. If a non-uniform model is used,
 fio will disable use of the random map.
 .TP
+.BI percentage_random \fR=\fPint
+For a random workload, set how big a percentage should be random. This defaults
+to 100%, in which case the workload is fully random. It can be set from
+anywhere from 0 to 100.  Setting it to 0 would make the workload fully
+sequential.
+.TP
+.BI percentage_sequential \fR=\fPint
+See \fBpercentage_random\fR.
+.TP
 .B norandommap
 Normally \fBfio\fR will cover every block of the file when doing random I/O. If
 this parameter is given, a new offset will be chosen without looking at past
@@ -690,7 +702,12 @@ Pretend to spend CPU time for given number of microseconds, sleeping the rest
 of the time specified by \fBthinktime\fR.  Only valid if \fBthinktime\fR is set.
 .TP
 .BI thinktime_blocks \fR=\fPint
-Number of blocks to issue before waiting \fBthinktime\fR microseconds.
+Only valid if thinktime is set - control how many blocks to issue, before
+waiting \fBthinktime\fR microseconds. If not set, defaults to 1 which will
+make fio wait \fBthinktime\fR microseconds after every block. This
+effectively makes any queue depth setting redundant, since no more than 1 IO
+will be queued before we have to complete it and do our thinktime. In other
+words, this setting effectively caps the queue depth if the latter is larger.
 Default: 1.
 .TP
 .BI rate \fR=\fPint