Re: [Qemu-devel] Windows slow boot

[Michael Tokarev]

On 16.08.2012 14:47, Richard Davies wrote:

> http://marc.info/?l=qemu-devel&m=134304194329745
> 
> 
> We have been experiencing this problem for a while now too, using qemu-kvm
> (currently at 1.1.1).
> 
> Unfortunately, hv_relaxed doesn't seem to fix it. The following command line
> produces the issue:
> 
> qemu-kvm -nodefaults -m 4096 -smp 8 -cpu host,hv_relaxed -vga cirrus 
> -usbdevice tablet -vnc :99 -monitor stdio -hda test.img

Just one question: did you try explicitly using hugepages?
For that,
 - reserve some amount of hugepages (echo something > 
/proc/sys/vm/nr_hugepages),
 - mount hugetlbfs to somewhere, like, /dev/hugetlbfs
 - use -mem-path=/dev/hugetlbfs qemu option

This may also reduce your lock contention.  Sure, hugepages have
some minus sides too, but I think it is worth to try anyway -
for a single VM or for whole lot of VMs (for that you'll have
to reserve much more memory after host boot).

/mjt