Subject: Re: [PATCH] Re: Bad network performance over 2Gbps

From: Rick Jones <[email-masked]>
Date: Mon, 21 Apr 2008 09:42:00 -0700

Bodo Eggert wrote:
> Kok, Auke <[email-masked]> wrote:
> 
> 
>>[X86] IRQBALANCE: Mark as BROKEN and disable by default
>>
>>The IRQBALANCE option causes interrupts to bounce all around on SMP systems
>>quickly burying the CPU in migration cost and cache misses. Mainly affected
>>are network interrupts and this results in one CPU pegged in softirqd
>>completely.
> 
> 
> If this is the problem, maybe it would help to only balance the IRQs each
> e.g. ten seconds? Unfortunately I have no SMP system to try it out.

Be it kernel or user space, for consistent benchmark results it needs to 
be able to be turned-off without turning the code.  That leaves me in 
agreement with Stephen that if it must exist, the user space one would 
be preferable.  It can be easily terminated with extreme prejudice.

rick jones