Re: 2.6.27rc1 cannot boot more than 8CPUs

Max Krasnyansky
2008-08-06T20:12:14Z

Li Zefan wrote:
> Max Krasnyansky wrote:
>> Jeff Chua wrote:
>>> On Wed, Aug 6, 2008 at 11:54 AM, Max Krasnyansky <maxk@qualcomm.com>
>>> wrote:
>>>
>>>> Are you running 32-bit kernel ?
>>> Yes. But, does it matter?
>> It used to. 64-bit kernel used to handle maxcpus option as documented in
>> the Documentation/cpu-hotplug.txt and 32-bit one was broken.
>> I just looked at the latest code and realized that both are now broken.
>> They ignore cpu id > maxcpus instead of not-booting them.
>>
>
> Yes. I have an x86_64 box with 4 cpus, but yesterday when I booted up with maxcpus=2,
> I didn't see the other 2 cpus.
>
>> I'll send a patch that fixes that tomorrow.
>>
>
> greate :)

I just sent it and CC'ed both of you guys.
[PATCH] Resurect proper handling of maxcpus= kernel option

Jeff, maybe you can try again booting with maxcpus=8 and then bringing
them online one by one to see where/what fails.

Max