Add support for the iomem_align option
This allows detailed control of the alignment of the IO buffers
that fio uses.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/HOWTO b/HOWTO
index f323c20..3107d3a 100644
--- a/HOWTO
+++ b/HOWTO
@@ -704,6 +704,15 @@
location should point there. So if it's mounted in /huge,
you would use mem=mmaphuge:/huge/somefile.
+iomem_align=int 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 iodepth the alignment of the following buffers
+ are given by the bs used. In other words, if using a bs that is
+ a multiple of the page sized in the system, all buffers will
+ be aligned to this value. If using a bs that is not page
+ aligned, the alignment of subsequent IO memory buffers is the
+ sum of the iomem_align and bs used.
+
hugepage-size=int
Defines the size of a huge page. Must at least be equal
to the system setting, see /proc/meminfo. Defaults to 4MiB.