Re: 256 apic id for amd64

["Siddha, Suresh B" <suresh.b.siddha@intel.com>]

YH, I suggest you root cause the exact issue and if it turns out to
be a platform issue, then we can have a kernel workaround for that specific
platform. As Andi mentioned, we don't have any kernel limitations with
BSP apicid != 0.

On Mon, Jan 10, 2005 at 07:44:37PM +0100, Andi Kleen wrote:
> On Mon, Jan 10, 2005 at 10:32:42AM -0800, Yinghai Lu wrote:
> > Case 1: lift core0/node0 to use 16, and core1/node0 to use 17.....
> > Case 2: core0/node0-->0, core1/node0-->1, core0/node1-->18,
> > core1/node1-->19...
> > Case 3: core0/node0-->0, core1/node0-->17, core0/node1-->18,
> > core1/node1-->19...
> > 
> > Case 1 will make jiffies not happy and it will hang on calibrate_dalay. (
> > jiffies is not changing).
> 
> That's because it needs physical APIC mode to handle CPU IDs >7, and that is
>  not implemented in the flat case. I added it now, but you likely don't need 
> it anyways.

Andi, we don't need physical APIC mode just to handle CPU APIC ID's > 7
when the total number of cpu's in the system is < 8. Right?

thanks,
suresh