Commit addd386d authored Apr 24, 2018 by Dariusz Stojaczyk Committed by Jim Harris Apr 25, 2018

doc/virtio: mention 2MB hugepage support



Also updated the CHANGELOG.

Change-Id: I9040505f689aab51fc26ab47d5a10438e35f9fc4
Signed-off-by: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/408830


Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: John Kariuki <John.K.Kariuki@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>

parent 30f369f7

CHANGELOG.md

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		@@ -114,6 +114,12 @@ the Virtio SCSI driver. See the
		[Virtio Block](http://www.spdk.io/doc/bdev.html#bdev_config_virtio_blk) reference for
		more information.

		### Virtio with 2MB hugepages

		Previous 1GB hugepage limitation has now been lifted. A new '-g' command-line option
		enables SPDK Virtio to work with 2MB hugepages.
		See [2MB hugepages](http://www.spdk.io/doc/virtio.html#virtio_2mb) for details.

		## v18.01: Blobstore Thin Provisioning

		### Build System

doc/virtio.md

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		@@ -18,3 +18,16 @@ the overall I/O performance.
		This Virtio library is currently used to implement two bdev modules:
		@ref bdev_config_virtio_scsi and @ref bdev_config_virtio_blk.
		These modules will export generic SPDK block devices usable by any SPDK application.

		# 2MB hugepages {#virtio_2mb}

		vhost-user specification puts a limitation on the number of "memory regions" used (8).
		Each region corresponds to one file descriptor, and DPDK - as SPDK's memory allocator -
		uses one file per hugepage by default. So by default this makes SPDK Virtio practical
		with only 1GB hugepages. To run an SPDK app using Virtio initiator with 2MB hugepages
		it is required to pass '-g' command-line option . This forces DPDK to create a single
		non-physically-contiguous hugetlbfs file for all its memory.

		This functionality requires latest DPDK changes that are officially landing in DPDK
		18.05, but have been also backported to spdk-18.02 branch of our internal DPDK fork
		which is currently used as a default git submodule for SPDK.