Avi Kivity wrote:
On 08/27/2009 11:42 PM, Andrew Theurer wrote:
On Thu, 2009-08-27 at 19:21 +0300, Avi Kivity wrote:
On 08/27/2009 06:41 PM, Gleb Natapov wrote:
Don't call adjust_vmx_controls() two times for the same control.
It restores options that was dropped earlier.
Applied, thanks. Andrew, if you rerun your benchmark atop kvm.git
'next' branch, I believe you will see dramatically better results.
Yes! CPU is much lower:
user nice system irq softirq guest idle iowait
5.81 0.00 9.48 0.08 1.04 21.32 57.86 4.41
previous CPU:
user nice system irq softirq guest idle iowait
5.67 0.00 11.64 0.09 1.05 31.90 46.06 3.59
How does it compare to the other hypervisor now?
My original results for other hypervisor were a little inaccurate. They
mistakenly used 2 vcpu guests. New runs with 1 vcpu guests (as used in
kvm) have slightly lower CPU utilization. Anyway, here's the breakdown:
CPU percent more CPU
kvm-master/qemu-kvm-87: 50.15 78%
kvm-next/qemu-kvm-87: 37.73 34%
new oprofile:
samples % app name symbol name
885444 53.2905 kvm-intel.ko vmx_vcpu_run
guest mode = good
38090 2.2924 qemu-system-x86_64 cpu_physical_memory_rw
34764 2.0923 qemu-system-x86_64 phys_page_find_alloc
14730 0.8865 qemu-system-x86_64 qemu_get_ram_ptr
10814 0.6508 vmlinux-2.6.31-rc5-autokern1 copy_user_generic_string
10871 0.6543 qemu-system-x86_64 virtqueue_get_head
8557 0.5150 qemu-system-x86_64 virtqueue_avail_bytes
7173 0.4317 qemu-system-x86_64 lduw_phys
4122 0.2481 qemu-system-x86_64 ldl_phys
3339 0.2010 qemu-system-x86_64 virtqueue_num_heads
4129 0.2485 libpthread-2.5.so pthread_mutex_lock
virtio and related qemu overhead: 8.2%.
25278 1.5214 vmlinux-2.6.31-rc5-autokern1 native_write_msr_safe
12278 0.7390 vmlinux-2.6.31-rc5-autokern1 native_read_msr_safe
This will be reduced to if we move virtio to kernel context.
Are there plans to move that to kernel for disk, too?
12380 0.7451 vmlinux-2.6.31-rc5-autokern1 native_set_debugreg
3550 0.2137 vmlinux-2.6.31-rc5-autokern1 native_get_debugreg
A lot less than before, but still annoying.
4631 0.2787 vmlinux-2.6.31-rc5-autokern1 mwait_idle
idle=halt may improve this, mwait is slow.
I can try idle-halt on the host. I actually assumed it would be using
that, but I'll check.
Thanks,
-Andrew
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