Merge branch 'ci' of https://github.com/sitsofe/fio

[fio.git] / fio.1

diff --git a/fio.1 b/fio.1
index ab978ab3aeb2914ac9d48e2f6cbb5ca2a728132c..14359e609a961eab7a1bce506bdd01a2cc5a67aa 100644 (file)
--- a/fio.1
+++ b/fio.1
@@ -242,37 +242,37 @@ prefixes. To specify power-of-10 decimal values defined in the
 International System of Units (SI):
 .RS
 .P
-ki means kilo (K) or 1000
+Ki means kilo (K) or 1000
 .RE
 .RS
-mi means mega (M) or 1000**2
+Mi means mega (M) or 1000**2
 .RE
 .RS
-gi means giga (G) or 1000**3
+Gi means giga (G) or 1000**3
 .RE
 .RS
-ti means tera (T) or 1000**4
+Ti means tera (T) or 1000**4
 .RE
 .RS
-pi means peta (P) or 1000**5
+Pi means peta (P) or 1000**5
 .RE
 .P
 To specify power-of-2 binary values defined in IEC 80000-13:
 .RS
 .P
-k means kibi (Ki) or 1024
+K means kibi (Ki) or 1024
 .RE
 .RS
-m means mebi (Mi) or 1024**2
+M means mebi (Mi) or 1024**2
 .RE
 .RS
-g means gibi (Gi) or 1024**3
+G means gibi (Gi) or 1024**3
 .RE
 .RS
-t means tebi (Ti) or 1024**4
+T means tebi (Ti) or 1024**4
 .RE
 .RS
-p means pebi (Pi) or 1024**5
+P means pebi (Pi) or 1024**5
 .RE
 .P
 With `kb_base=1024' (the default), the unit prefixes are opposite
@@ -1044,6 +1044,20 @@ we simply do polling.
 Low watermark indicating when to start filling the queue again.  Default:
 \fBiodepth\fR.
 .TP
+.BI serialize_overlap \fR=\fPbool
+Serialize in-flight I/Os that might otherwise cause or suffer from data races.
+When two or more I/Os are submitted simultaneously, there is no guarantee that
+the I/Os will be processed or completed in the submitted order. Further, if
+two or more of those I/Os are writes, any overlapping region between them can
+become indeterminate/undefined on certain storage. These issues can cause
+verification to fail erratically when at least one of the racing I/Os is
+changing data and the overlapping region has a non-zero size. Setting
+\fBserialize_overlap\fR tells fio to avoid provoking this behavior by explicitly
+serializing in-flight I/Os that have a non-zero overlap. Note that setting
+this option can reduce both performance and the \fBiodepth\fR achieved.
+Additionally this option does not work when \fBio_submit_mode\fR is set to
+offload. Default: false.
+.TP
 .BI io_submit_mode \fR=\fPstr
 This option controls how fio submits the IO to the IO engine. The default is
 \fBinline\fR, which means that the fio job threads submit and reap IO directly.