Re: [RFC PATCH 0/4] Gang scheduling in CFS

From: Nikunj A Dadhania
Date: Mon Dec 26 2011 - 06:37:22 EST

On Mon, 26 Dec 2011 11:05:01 +0200, Avi Kivity <avi@xxxxxxxxxx> wrote:
> On 12/26/2011 05:14 AM, Nikunj A Dadhania wrote:
> > >
> > > btw you can get an additional speedup by enabling x2apic, for
> > > default_send_IPI_mask_logical().
> > >
> > In the host?
> >
> In the host,
The machine(IBM x3650 M2, Nehalem) does not seem to support x2apic.

I have enabled the following in my config;

[root@krm1 linux-tip]# grep X2APIC .config
[root@krm1 linux-tip]#

And booted the kernel with "apic=verbose" command.

[root@krm1 linux-tip]# dmesg | grep -i x2apic
[root@krm1 linux-tip]#

Does not give anything. I safely assumed that x2apic is not
supported. Is there something to do in the bios to enable this?

> for the guest:
> qemu -cpu ...,+x2apic
I need to try this, i have libvirt setup. Let me dig how to enable this
through xml file.


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