Add support for the iomem_align option

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index f323c204d3c67be97e98926ae8efd0ae1d82314d..3107d3a15e6b4488dcd8626264b791d078459d1e 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -704,6 +704,15 @@ mem=str            Fio can use various types of memory as the io unit buffer.
                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.