Re: [PATCH take3 0/12] Support vector domain on ia64

[Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>]

Hi Eric,

Eric W. Biederman wrote:
> Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> writes:
> 
>> - define NR_IRQS as follow:
>>
>>   Vector domain can provide the number of irqs being proportional to the
>>   number of CPUs theoretically. However, the relation between them is
>>   actually not linear, especially in large system. To avoid the memory
>>   consumption derived from too many irqs, I define NR_IRQS as follows:
>>
>>   #if (NR_VECTORS + 32 * NR_CPUS) < 1024
>>   #define NR_IRQS (NR_VECTORS + 32 * NR_CPUS)
>>   #else
>>   #define NR_IRQS 1024
>>   #endif
> 
> 
> Below is my old patch to address this in a different way.
> Basically this moves the per cpu counter of the number of
> times an irq has happened on an individual cpu out of the
> per cpu area.  Honestly I think this might even have better
> cache performance.

Sorry for my late reply.

I overviewed your patch and the patch looks good to me. It can improve
not only ia64 vector domain but also x86_64 vector domain. I'll consider
testing the patch after rebasing it, and if it'll be OK, including your
idea (or similar one) into my patchset.

BTW, I googled to find the discussion related to your patch, but can't find
it at all. Where did you submit it to?

Thanks,
Yasuaki Ishimatsu