[Qemu-discuss] SMP: Unable to load the cpu 1 under stress test

[Romain Naour]

Hello,

I'm using -smp option to enable several cpu on the guest.
I noticed that the cpu 1 (cpu 2 in htop) is not used at all by the guest even 
under stress test programme.

Qemu started with:
qemu-system-i386 -cpu n270,check -smp 3 -usbdevice keyboard \
-name qemu-img -drive file=qemu-img.qcow2,media=disk,cache=writeback

On the guest:
$ stress --cpu 8 &
$ htop

htop:
1 [###################100%]
2 [                     0%]
3 [###################100%]

It seems strange that the cpu 1 remains idle.

I'm using qemu 1.5.3
host: debian 7 (32bis)
guest: custom OS (32bis) (buildroot based)


With lastest qemu from git (qemu-1.6.50), the cpu 2 is tuck at 50%

htop:
1 [##############*****100%]
2 [***********         50%]
3 [###################100%]


Another test with kvm enabled (qemu-1.6.50):
qemu-system-i386 -cpu host -enable-kvm -smp 3 -usbdevice keyboard \
-name qemu-img -drive file=qemu-img.qcow2,media=disk,cache=writeback

htop:
1 [###################100%]
2 [                     0%]
3 [###################100%]

Only 2 cpu are used on the host.

There is a known issue with smp option ?

Thanks,
-- 
Romain Naour

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