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

From: Rick Jones
Date: Mon Apr 21 2008 - 12:42:21 EST


Bodo Eggert wrote:
Kok, Auke <auke-jan.h.kok@xxxxxxxxx> 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
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