[Qemu-devel] Large guest boot hangs the host.

[Qemu-devel] Large guest boot hangs the host.

[Chegu Vinod]

Hello,

I have been noticing host hangs when trying to boot large guests 
(>=40Vcpus) with the current upstream qemu.

Host is running 3.8.2 kernel.
qemu is the latest one from qemu.git.

Example qemu command line listed below... this used to work with a 
slightly older qemu (about 1.5 weeks ago and on the same host with the 
3.8.2 kernel)      'am trying to determine the cause of the host 
hang...but wanted to check to see if anyone
else has seen it...

Thanks
Vinod


----


/usr/local/bin/qemu-system-x86_64 \
-enable-kvm \
-cpu host \
-smp sockets=8,cores=10,threads=1 \
-numa node,nodeid=0,cpus=0-9,mem=64g \
-numa node,nodeid=1,cpus=10-19,mem=64g \
-numa node,nodeid=2,cpus=20-29,mem=64g \
-numa node,nodeid=3,cpus=30-39,mem=64g \
-numa node,nodeid=4,cpus=40-49,mem=64g \
-numa node,nodeid=5,cpus=50-59,mem=64g \
-numa node,nodeid=6,cpus=60-69,mem=64g \
-numa node,nodeid=7,cpus=70-79,mem=64g \
-m 524288 \
-mem-path /dev/hugepages \
-name vm1 \
-chardev 
socket,id=charmonitor,path=/var/lib/libvirt/qemu/vm1.monitor,server,nowait \
-drive 
file=/dev/libvirt_lvm/vm1,if=none,id=drive-virtio-disk0,format=raw,cache=none,aio=native 
\
-device 
virtio-blk-pci,scsi=off,bus=pci.0,addr=0x5,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1 
\
-monitor stdio \
-net nic,model=virtio,macaddr=52:54:00:71:01:01,netdev=nic-0 \
-netdev tap,id=nic-0,ifname=tap0,script=no,downscript=no,vhost=on \
-vnc :4