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
 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.
 .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
 .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.
 .TP
 .BI unlink \fR=\fPbool
 Unlink job files when done.  Default: false.