BKM: improve qemu performance - Revision history

Gzhai: /* Enable SMP */

2011-12-06T13:43:14Z

Enable SMP

← Older revision		Revision as of 13:43, 6 December 2011
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	* enable smp configuration in yocto kernel		* enable smp configuration in yocto kernel
	* enable smp option for qemu, like '''-smp 4''' to give 4 vcpu to guest.		* enable smp option for qemu, like '''-smp 4''' to give 4 vcpu to guest.
	~~----~~
	qemu built from yocto may have some bug that only 1 vcpu is truly used by guest(You can use top -d1 inside guest to see only 100% CPU usage). Pls. switch to the qemu in the linux distribution, say ubuntu, as one workaround.		''qemu built from yocto may have some bug that only 1 vcpu is truly used by guest(You can use top -d1 inside guest to see only 100% CPU usage). Pls. switch to the qemu in the linux distribution, say ubuntu, as one workaround.''

	== Add extra disk space ==		== Add extra disk space ==

Gzhai: /* Enable SMP */

2011-12-06T13:41:35Z

Enable SMP

← Older revision		Revision as of 13:41, 6 December 2011
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	* enable smp configuration in yocto kernel		* enable smp configuration in yocto kernel
	* enable smp option for qemu, like '''-smp 4''' to give 4 vcpu to guest.		* enable smp option for qemu, like '''-smp 4''' to give 4 vcpu to guest.
			----
			qemu built from yocto may have some bug that only 1 vcpu is truly used by guest(You can use top -d1 inside guest to see only 100% CPU usage). Pls. switch to the qemu in the linux distribution, say ubuntu, as one workaround.

	== Add extra disk space ==		== Add extra disk space ==

Gzhai at 13:38, 6 December 2011

2011-12-06T13:38:02Z

← Older revision		Revision as of 13:38, 6 December 2011
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	Following is one example		Following is one example
	-net nic,model=virtio,vlan=0 -net tap,vlan=0,ifname=tap0,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown -drive file=/home/source.img,if=virtio -drive file=/home/build.img,if=virtio		-net nic,model=virtio,vlan=0 -net tap,vlan=0,ifname=tap0,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown -drive file=/home/source.img,if=virtio -drive file=/home/build.img,if=virtio

			== Enable VTd to for NIC/Block device ==
			Enable VTd with KVM can directed assign PCI device(like NIC or USB disk) to guest, then achieve almost native performance. Pls. make sure your chipset and bios support VTd.
			Details is to be coming soon:)

Gzhai: /* Enable virtio block and network device */

2011-12-06T13:34:30Z

Enable virtio block and network device

← Older revision		Revision as of 13:34, 6 December 2011
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	+CONFIG_VIRTIO_BLK=y		+CONFIG_VIRTIO_BLK=y
	* change qemu block device parameter from "-hda <your_disk_image" to '''-drive file=<your_disk_image>,if=virtio'''		* change qemu block device parameter from "-hda <your_disk_image" to '''-drive file=<your_disk_image>,if=virtio'''
			* modify qemu NIC parameter: change the -net nic option to include '''model=virtio'''
			Following is one example
			-net nic,model=virtio,vlan=0 -net tap,vlan=0,ifname=tap0,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown -drive file=/home/source.img,if=virtio -drive file=/home/build.img,if=virtio

Gzhai at 13:26, 6 December 2011

2011-12-06T13:26:54Z

← Older revision		Revision as of 13:26, 6 December 2011
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	== Enable virtio block and network device ==		== Enable virtio block and network device ==
	Virtio (block/network) device is a para-virtualized device for kvm guest. It is different from normal emulated hard drive, because it is simply faster.		Virtio (block/network) device is a para-virtualized device for kvm guest. It is different from normal emulated hard drive, because it is simply faster.
	# enable yocto kernel configuration		* enable yocto kernel configuration
	+CONFIG_VIRTIO=y		+CONFIG_VIRTIO=y
	+CONFIG_VIRTIO_PCI=y		+CONFIG_VIRTIO_PCI=y
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	+CONFIG_VIRTIO_NET=y		+CONFIG_VIRTIO_NET=y
	+CONFIG_VIRTIO_BLK=y		+CONFIG_VIRTIO_BLK=y
	# change qemu block device parameter from "-hda <your_disk_image" to '''-drive file=<your_disk_image>,if=virtio'''		* change qemu block device parameter from "-hda <your_disk_image" to '''-drive file=<your_disk_image>,if=virtio'''

Gzhai at 13:24, 6 December 2011

2011-12-06T13:24:44Z

← Older revision		Revision as of 13:24, 6 December 2011
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	== Enable virtio block and network device ==		== Enable virtio block and network device ==
			Virtio (block/network) device is a para-virtualized device for kvm guest. It is different from normal emulated hard drive, because it is simply faster.
			# enable yocto kernel configuration
			+CONFIG_VIRTIO=y
			+CONFIG_VIRTIO_PCI=y
			+CONFIG_VIRTIO_BALLOON=y
			+CONFIG_VIRTIO_RING=y
			+CONFIG_VIRTIO_NET=y
			+CONFIG_VIRTIO_BLK=y
			# change qemu block device parameter from "-hda <your_disk_image" to '''-drive file=<your_disk_image>,if=virtio'''

Gzhai at 13:14, 6 December 2011

2011-12-06T13:14:25Z

← Older revision		Revision as of 13:14, 6 December 2011
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	= improve qemu performance =		[[Link title]]= improve qemu performance =
	Qemu in yocto is emulator, and is slow when running huge task inside. E.g. running yocto build inside qemu. This article illustrate possible performance improvement to accelerate it		Qemu in yocto is emulator, and is slow when running huge task inside. E.g. running yocto build inside qemu. This article illustrate possible performance improvement to accelerate it

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	Sometimes, workload inside qemu requires huge memory. Fail to do this lead performance drop. So pls. add enough memory to qemu via '''-m 2048''' (2G).		Sometimes, workload inside qemu requires huge memory. Fail to do this lead performance drop. So pls. add enough memory to qemu via '''-m 2048''' (2G).

	== ~~enable~~ SMP ==		== Enable SMP ==
	If workload inside qemu is CPU-intensive, you can enable smp:		If workload inside qemu is CPU-intensive, you can enable smp:
	* enable smp configuration in yocto kernel		* enable smp configuration in yocto kernel
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	append this disk image to qemu via '''-hdb'''(need further changes if need virtio block device)		append this disk image to qemu via '''-hdb'''(need further changes if need virtio block device)

			== Create network environment ==
			Default qemu in yocto talk with host via simple 192.168.7.X, you can use bridge to make the guest act as one true machine, E.g download source code from outside. Pls. see http://www.linux-kvm.org/page/Networking#public_bridge for details

			== Enable virtio block and network device ==

Gzhai at 08:31, 6 December 2011

2011-12-06T08:31:45Z

← Older revision		Revision as of 08:31, 6 December 2011
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	== Add extra disk space ==		== Add extra disk space ==
	If workload inside qemu is disk-intensive, it may requires huge disk space. You can set up NFS server or add extra disk image, which is preferred as NFS server introduce extra network workload.		If workload inside qemu is disk-intensive, it may requires huge disk space. You can set up NFS server or add extra disk image, which is preferred as NFS server introduce extra network workload.
			Following steps to create a new disk image(10G) with ext3 file system:
			$ sudo dd if=/dev/zero of=b.img bs=1G count=10
			$ sudo losetup /dev/loop0 b.img
			$ sudo fdisk /dev/loop0
			Then create one new single partition
			$ sudo mkfs.ext3 /dev/loop0
			to create ext3 file system
			$ sudo losetup -d /dev/loop0

			append this disk image to qemu via '''-hdb'''(need further changes if need virtio block device)

Gzhai at 06:44, 6 December 2011

2011-12-06T06:44:01Z

← Older revision		Revision as of 06:44, 6 December 2011
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	== Add extra disk space ==		== Add extra disk space ==
	If workload inside qemu is disk-intensive.		If workload inside qemu is disk-intensive, it may requires huge disk space. You can set up NFS server or add extra disk image, which is preferred as NFS server introduce extra network workload.

Gzhai at 06:01, 6 December 2011

2011-12-06T06:01:36Z

← Older revision		Revision as of 06:01, 6 December 2011
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	* enable smp configuration in yocto kernel		* enable smp configuration in yocto kernel
	* enable smp option for qemu, like '''-smp 4''' to give 4 vcpu to guest.		* enable smp option for qemu, like '''-smp 4''' to give 4 vcpu to guest.

			== Add extra disk space ==
			If workload inside qemu is disk-intensive.