[Qemu-devel] Significant slowdown after qemu-kvm-1.2.0

[Qemu-devel] Significant slowdown after qemu-kvm-1.2.0

[jinho hwang]

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Hi Guys,

I am new to kvm development (used to work on Xen). I used qemu-kvm-1.2.0
first, and then due to pci memory size (x64 bit support), I switched from
1.2.0 to qemu-kvm-1.5.0 (same for 1.3.0~). After that, my VM slows down
significantly including booting and execution. Also, sometimes kernel
messages "CPU stuck for x seconds" show in dmesg. I think CPU scheduling
has been changed or should be set up properly, but I have no clue for now.
Can anyone help me to figure out this? I really need some fast VMs as I
used to run with qemu-kvm-1.2.0.

I am currently running ubuntu-12.10_64 in VM, and my configure was

./configure --prefix=/usr --target-list=x86_64-linux-user,x86_64-softmmu

sudo qemu-system-x86_64 -name vm -m 1g -hda /home/jinho/virt/vms/vm1.img
-device e1000,netdev=net0,mac=00:0c:29:f0:bc:33 -netdev tap,id=net0 -vnc
135.207.127.181:1

No particular environmental settings are done.

Thank you,

Jinho

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Re: [Qemu-devel] Significant slowdown after qemu-kvm-1.2.0

[Paolo Bonzini]

Il 01/07/2013 23:51, jinho hwang ha scritto:
> Hi Guys,
> 
> I am new to kvm development (used to work on Xen). I used qemu-kvm-1.2.0
> first, and then due to pci memory size (x64 bit support), I switched
> from 1.2.0 to qemu-kvm-1.5.0 (same for 1.3.0~).

There is no qemu-kvm 1.5.0.  You are using qemu 1.5.0.

> After that, my VM slows
> down significantly including booting and execution. Also, sometimes
> kernel messages "CPU stuck for x seconds" show in dmesg. I think CPU
> scheduling has been changed or should be set up properly, but I have no
> clue for now. Can anyone help me to figure out this? I really need some
> fast VMs as I used to run with qemu-kvm-1.2.0.
> 
> I am currently running ubuntu-12.10_64 in VM, and my configure was
> 
> ./configure --prefix=/usr --target-list=x86_64-linux-user,x86_64-softmmu
> 
> sudo qemu-system-x86_64 -name vm -m 1g -hda /home/jinho/virt/vms/vm1.img
> -device e1000,netdev=net0,mac=00:0c:29:f0:bc:33 -netdev tap,id=net0 -vnc
> 135.207.127.181:1 <http://135.207.127.181:1>

You are not using kvm.  Add --enable-kvm to the command line.

Paolo

[Qemu-devel] Re: Significant slowdown after qemu-kvm-1.2.0

[jinho hwang]

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Hi Paolo,

Thank you for your reply. I tried qemu-1.5.0 with --enable-kvm, but there
is still a big difference between qemu-kvm-1.2.0 and qemu-1.5.0. They both
use the same command line to create VM. Am I missing something in the
command-line?

sudo qemu-system-x86_64 -name vm -m 1g -hda /home/jinho/virt/vms/vm1.img
-device e1000,netdev=net0,mac=00:0c:29:f0:bc:33 -netdev tap,id=net0 -vnc :1

Thank you,

Jinho

On Mon, Jul 1, 2013 at 5:54 PM, Paolo Bonzini <pbonzini@redhat.com> wrote:

> Il 01/07/2013 23:51, jinho hwang ha scritto:
> > Hi Guys,
> >
> > I am new to kvm development (used to work on Xen). I used qemu-kvm-1.2.0
> > first, and then due to pci memory size (x64 bit support), I switched
> > from 1.2.0 to qemu-kvm-1.5.0 (same for 1.3.0~).
>
> There is no qemu-kvm 1.5.0.  You are using qemu 1.5.0.
>
> > After that, my VM slows
> > down significantly including booting and execution. Also, sometimes
> > kernel messages "CPU stuck for x seconds" show in dmesg. I think CPU
> > scheduling has been changed or should be set up properly, but I have no
> > clue for now. Can anyone help me to figure out this? I really need some
> > fast VMs as I used to run with qemu-kvm-1.2.0.
> >
> > I am currently running ubuntu-12.10_64 in VM, and my configure was
> >
> > ./configure --prefix=/usr --target-list=x86_64-linux-user,x86_64-softmmu
> >
> > sudo qemu-system-x86_64 -name vm -m 1g -hda /home/jinho/virt/vms/vm1.img
> > -device e1000,netdev=net0,mac=00:0c:29:f0:bc:33 -netdev tap,id=net0 -vnc
> > 135.207.127.181:1 <http://135.207.127.181:1>
>
> You are not using kvm.  Add --enable-kvm to the command line.
>
> Paolo
>

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Re: [Qemu-devel] Significant slowdown after qemu-kvm-1.2.0

[Andreas Färber]

Hi,

Am 02.07.2013 00:24, schrieb jinho hwang:
> Thank you for your reply. I tried qemu-1.5.0 with --enable-kvm, but
> there is still a big difference between qemu-kvm-1.2.0 and qemu-1.5.0.
> They both use the same command line to create VM. Am I missing something
> in the command-line?
> 
> sudo qemu-system-x86_64 -name vm -m 1g -hda /home/jinho/virt/vms/vm1.img
> -device e1000,netdev=net0,mac=00:0c:29:f0:bc:33 -netdev tap,id=net0 -vnc :1

Yes, you are still missing -enable-kvm on the QEMU command line, or
alternatively the more modern -machine accel=kvm.

Regards,
Andreas

P.S. Please avoid top-posting and HTML on the mailing list.

> On Mon, Jul 1, 2013 at 5:54 PM, Paolo Bonzini <pbonzini@redhat.com
> <mailto:pbonzini@redhat.com>> wrote:
> 
>     Il 01/07/2013 23:51, jinho hwang ha scritto:
>     > Hi Guys,
>     >
>     > I am new to kvm development (used to work on Xen). I used
>     qemu-kvm-1.2.0
>     > first, and then due to pci memory size (x64 bit support), I switched
>     > from 1.2.0 to qemu-kvm-1.5.0 (same for 1.3.0~).
> 
>     There is no qemu-kvm 1.5.0.  You are using qemu 1.5.0.
> 
>     > After that, my VM slows
>     > down significantly including booting and execution. Also, sometimes
>     > kernel messages "CPU stuck for x seconds" show in dmesg. I think CPU
>     > scheduling has been changed or should be set up properly, but I
>     have no
>     > clue for now. Can anyone help me to figure out this? I really need
>     some
>     > fast VMs as I used to run with qemu-kvm-1.2.0.
>     >
>     > I am currently running ubuntu-12.10_64 in VM, and my configure was
>     >
>     > ./configure --prefix=/usr
>     --target-list=x86_64-linux-user,x86_64-softmmu
>     >
>     > sudo qemu-system-x86_64 -name vm -m 1g -hda
>     /home/jinho/virt/vms/vm1.img
>     > -device e1000,netdev=net0,mac=00:0c:29:f0:bc:33 -netdev
>     tap,id=net0 -vnc
>     > 135.207.127.181:1 <http://135.207.127.181:1>
>     <http://135.207.127.181:1>
> 
>     You are not using kvm.  Add --enable-kvm to the command line.
> 
>     Paolo
> 


-- 
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg

Re: [Qemu-devel] Significant slowdown after qemu-kvm-1.2.0

[jinho hwang]

On Mon, Jul 1, 2013 at 7:48 PM, Andreas Färber <afaerber@suse.de> wrote:
>
> Hi,
>
> Am 02.07.2013 00:24, schrieb jinho hwang:
> > Thank you for your reply. I tried qemu-1.5.0 with --enable-kvm, but
> > there is still a big difference between qemu-kvm-1.2.0 and qemu-1.5.0.
> > They both use the same command line to create VM. Am I missing something
> > in the command-line?
> >
> > sudo qemu-system-x86_64 -name vm -m 1g -hda /home/jinho/virt/vms/vm1.img
> > -device e1000,netdev=net0,mac=00:0c:29:f0:bc:33 -netdev tap,id=net0 -vnc :1
>
> Yes, you are still missing -enable-kvm on the QEMU command line, or
> alternatively the more modern -machine accel=kvm.
>
> Regards,
> Andreas
>
> P.S. Please avoid top-posting and HTML on the mailing list.

> > On Mon, Jul 1, 2013 at 5:54 PM, Paolo Bonzini <pbonzini@redhat.com
> > <mailto:pbonzini@redhat.com>> wrote:
> >
> >     Il 01/07/2013 23:51, jinho hwang ha scritto:
> >     > Hi Guys,
> >     >
> >     > I am new to kvm development (used to work on Xen). I used
> >     qemu-kvm-1.2.0
> >     > first, and then due to pci memory size (x64 bit support), I switched
> >     > from 1.2.0 to qemu-kvm-1.5.0 (same for 1.3.0~).
> >
> >     There is no qemu-kvm 1.5.0.  You are using qemu 1.5.0.
> >
> >     > After that, my VM slows
> >     > down significantly including booting and execution. Also, sometimes
> >     > kernel messages "CPU stuck for x seconds" show in dmesg. I think CPU
> >     > scheduling has been changed or should be set up properly, but I
> >     have no
> >     > clue for now. Can anyone help me to figure out this? I really need
> >     some
> >     > fast VMs as I used to run with qemu-kvm-1.2.0.
> >     >
> >     > I am currently running ubuntu-12.10_64 in VM, and my configure was
> >     >
> >     > ./configure --prefix=/usr
> >     --target-list=x86_64-linux-user,x86_64-softmmu
> >     >
> >     > sudo qemu-system-x86_64 -name vm -m 1g -hda
> >     /home/jinho/virt/vms/vm1.img
> >     > -device e1000,netdev=net0,mac=00:0c:29:f0:bc:33 -netdev
> >     tap,id=net0 -vnc
> >     > 135.207.127.181:1 <http://135.207.127.181:1>
> >     <http://135.207.127.181:1>
> >
> >     You are not using kvm.  Add --enable-kvm to the command line.
> >
> >     Paolo
> >
>
>
> --
> SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
> GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg

That works perfect! I only included --enable-kvm to configure, not
qemu-system-x86_64. Now it works very fast. I just registered e-mail
list, and found the qemu development is very active. Very good to be
part of it now. Thanks! - Jinho