+ bs size for the job, multiplied by the io depth given. Note
+ that for shmhuge and mmaphuge to work, the system must have
+ free huge pages allocated. This can normally be checked
+ and set by reading/writing /proc/sys/vm/nr_hugepages on a
+ Linux system. Fio assumes a huge page is 4MiB in size. So
+ to calculate the number of huge pages you need for a given
+ job file, add up the io depth of all jobs (normally one unless
+ iodepth= is used) and multiply by the maximum bs set. Then
+ divide that number by the huge page size. You can see the
+ size of the huge pages in /proc/meminfo. If no huge pages
+ are allocated by having a non-zero number in nr_hugepages,
+ using mmaphuge or shmhuge will fail. Also see hugepage-size.
+
+ mmaphuge also needs to have hugetlbfs mounted and the file
+ location should point there. So if it's mounted in /huge,
+ you would use mem=mmaphuge:/huge/somefile.
+
+hugepage-size=siint
+ Defines the size of a huge page. Must at least be equal
+ to the system setting, see /proc/meminfo. Defaults to 4MiB.
+ Should probably always be a multiple of megabytes, so using
+ hugepage-size=Xm is the preferred way to set this to avoid
+ setting a non-pow-2 bad value.