Update documentation for write_hint

[fio.git] / fio.1

diff --git a/fio.1 b/fio.1
index bc477a2e8cdb3dd0737ffe93079737d97380791f..5da9ecfc7905776057ecd0f80ed29715067b7975 100644 (file)
--- a/fio.1
+++ b/fio.1
@@ -564,10 +564,30 @@ Advise using \fBFADV_RANDOM\fR
 .RE
 .RE
 .TP
 .RE
 .RE
 .TP

-.BI fadvise_stream \fR=\fPint
-Use \fBposix_fadvise\fR\|(2) to advise the kernel what stream ID the
-writes issued belong to. Only supported on Linux. Note, this option
-may change going forward.
+.BI write_hint \fR=\fPstr
+Use \fBfcntl\fR|(2) to advise the kernel what life time to expect from a write.
+Only supported on Linux, as of version 4.13. The values are all relative to
+each other, and no absolute meaning should be associated with them. Accepted
+values are:
+.RS
+.RS
+.TP
+.B none
+No particular life time associated with this file.
+.TP
+.B short
+Data written to this file has a short life time.
+.TP
+.B medium
+Data written to this file has a medium life time.
+.TP
+.B long
+Data written to this file has a long life time.
+.TP
+.B extreme
+Data written to this file has a very long life time.
+.RE
+.RE

 .TP
 .BI size \fR=\fPint
 Total size of I/O for this job.  \fBfio\fR will run until this many bytes have
 .TP
 .BI size \fR=\fPint
 Total size of I/O for this job.  \fBfio\fR will run until this many bytes have