Wrap thread_data in thread_segment

[fio.git] / fio.1

diff --git a/fio.1 b/fio.1
index 74509bbd2ea434278a6970c14e71e965cc083cd0..481193254832befdd285394d6424c209b8805989 100644 (file)
--- a/fio.1
+++ b/fio.1
@@ -1462,9 +1462,31 @@ starting I/O if the platform and file type support it. Defaults to true.
 This will be ignored if \fBpre_read\fR is also specified for the
 same job.
 .TP
-.BI sync \fR=\fPbool
-Use synchronous I/O for buffered writes. For the majority of I/O engines,
-this means using O_SYNC. Default: false.
+.BI sync \fR=\fPstr
+Whether, and what type, of synchronous I/O to use for writes.  The allowed
+values are:
+.RS
+.RS
+.TP
+.B none
+Do not use synchronous IO, the default.
+.TP
+.B 0
+Same as \fBnone\fR.
+.TP
+.B sync
+Use synchronous file IO. For the majority of I/O engines,
+this means using O_SYNC.
+.TP
+.B 1
+Same as \fBsync\fR.
+.TP
+.B dsync
+Use synchronous data IO. For the majority of I/O engines,
+this means using O_DSYNC.
+.PD
+.RE
+.RE
 .TP
 .BI iomem \fR=\fPstr "\fR,\fP mem" \fR=\fPstr
 Fio can use various types of memory as the I/O unit buffer. The allowed
@@ -2215,7 +2237,7 @@ has a bit of extra overhead, especially for lower queue depth I/O where it
 can increase latencies. The benefit is that fio can manage submission rates
 independently of the device completion rates. This avoids skewed latency
 reporting if I/O gets backed up on the device side (the coordinated omission
-problem).
+problem). Note that this option cannot reliably be used with async IO engines.
 .SS "I/O rate"
 .TP
 .BI thinktime \fR=\fPtime