From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stephen Hemminger <stephen.hemminger@vyatta.com>
Subject: Re: [PATCH] Re: Bad network performance over 2Gbps
Date: Sat, 19 Apr 2008 12:23:54 -0700
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Cc: Kok@vger.kernel.org, Auke <auke-jan.h.kok@intel.com>,
	Ingo Molnar <mingo@elte.hu>,
	Thomas Gleixner <tglx@linutronix.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Anton Titov <a.titov@host.bg>, Chris Snook <csnook@redhat.com>,
	"H. Willstrand" <h.willstrand@gmail.com>, netdev@vger.kernel.org,
	Jesse Brandeburg <jesse.brandeburg@intel.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Andrew Morton <akpm@linux-foundation.org>
To: 7eggert@gmx.de
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Bodo Eggert wrote:
> Kok, Auke <auke-jan.h.kok@intel.com> 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.
>
>
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>   
The kernel level IRQBALANCE is useless. The userlevel irqbalance does 
the right thing,
it handles multi-core, and network devices, and all the other special cases.
*Don't use kernel level irqbalance*