Re: [RFC 00/15] x86_64: Optimize percpu accesses

From: Mike Travis
Date: Thu Jul 10 2008 - 20:58:55 EST


H. Peter Anvin wrote:
> Mike Travis wrote:
>>
>> Hmm, that might be the way to go.... At boot up time determine the
>> size of the system in terms of cpu count and memory available and
>> attempt to do the right thing, with startup options to override the
>> internal choices... ?
>>
>> (Surely a system that has a "gazillion ip tunnels" could modify it's
>> kernel start options... ;-)
>>
>> Unfortunately, we can't use a MODULE to support different options unless
>> we change how the kernel starts up (would need to mount the root fs
>> before starting secondary cpus.)
>>
>
> Using a module doesn't make any sense anyway. This is more what the
> kernel command line is for.
>
> -hpa


I was thinking that supporting virtual percpu addresses would take a fair
amount of code that, if living in a MODULE, wouldn't impact small systems.
But it seems to be not worth the effort... ;-)

Thanks,
Mike
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