Merge branch 'master' of ssh://router/data/git/fio

[fio.git] / fio.1

diff --git a/fio.1 b/fio.1
index fc055e4d8cb2dbd1e4b763ffd316aedcba4d667b..32993b61da4bccc9ba633da361bc1e47a68aaa08 100644 (file)
--- a/fio.1
+++ b/fio.1
@@ -512,6 +512,15 @@ the system must have free huge pages allocated.  \fBmmaphuge\fR also needs to
 have hugetlbfs mounted, and \fIfile\fR must point there.
 .RE
 .TP
+.BI iomem_align \fR=\fPint
+This indiciates the memory alignment of the IO memory buffers. Note that the
+given alignment is applied to the first IO unit buffer, if using \fBiodepth\fR
+the alignment of the following buffers are given by the \fBbs\fR used. In
+other words, if using a \fBbs\fR that is a multiple of the page sized in the
+system, all buffers will be aligned to this value. If using a \fBbs\fR that
+is not page aligned, the alignment of subsequent IO memory buffers is the
+sum of the \fBiomem_align\fR and \fBbs\fR used.
+.TP
 .BI hugepage\-size \fR=\fPint
 Defines the size of a huge page.  Must be at least equal to the system setting.
 Should be a multiple of 1MiB. Default: 4MiB.
@@ -535,7 +544,9 @@ If true, the files are not created until they are opened for IO by the job.
 .BI pre_read \fR=\fPbool
 If this is given, files will be pre-read into memory before starting the given
 IO operation. This will also clear the \fR \fBinvalidate\fR flag, since it is
-pointless to pre-read and then drop the cache.
+pointless to pre-read and then drop the cache. This will only work for IO
+engines that are seekable, since they allow you to read the same data
+multiple times. Thus it will not work on eg network or splice IO.
 .TP
 .BI unlink \fR=\fPbool
 Unlink job files when done.  Default: false.