engines/xnvme: add support for picking mem backend

[fio.git] / HOWTO.rst

diff --git a/HOWTO.rst b/HOWTO.rst
index 0fec38a76528145d20001ea369aa29124f986ce4..0a48a453774b574773ef8ea31b63ccb5db1598e6 100644 (file)
--- a/HOWTO.rst
+++ b/HOWTO.rst
@@ -2885,6 +2885,23 @@ with the caveat that when used on the command line, they must come after the
        Sets the subsystem NQN for fabrics. This is for xNVMe to utilize a
        fabrics target with multiple systems.
 
+.. option:: xnvme_mem=str : [xnvme]
+
+       Select the xnvme memory backend. This can take these values.
+
+       **posix**
+               This is the default posix memory backend for linux NVMe driver.
+       **hugepage**
+               Use hugepages, instead of existing posix memory backend. The
+               memory backend uses hugetlbfs. This require users to allocate
+               hugepages, mount hugetlbfs and set an enviornment variable for
+               XNVME_HUGETLB_PATH.
+       **spdk**
+               Uses SPDK's memory allocator.
+       **vfio**
+               Uses libvfn's memory allocator. This also specifies the use
+               of libvfn backend instead of SPDK.
+
 .. option:: xnvme_iovec=int : [xnvme]
 
        If this option is set. xnvme will use vectored read/write commands.