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Date: Thu, 20 Jun 2013 20:37:55 +0700
From: Eugene Grosbein <eugen@grosbein.net>
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To: "Eggert, Lars" <lars@netapp.com>
Subject: Re: hw.igb.num_queues default
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Cc: "freebsd-net@freebsd.org" <freebsd-net@freebsd.org>,
 Jack Vogel <jfvogel@gmail.com>
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On 20.06.2013 17:34, Eggert, Lars wrote:

> real memory  = 8589934592 (8192 MB)
> avail memory = 8239513600 (7857 MB)

> By default, the igb driver seems to set up one queue per detected CPU. Googling around, people seemed to suggest that limiting the number of queues makes things work better. I can confirm that setting hw.igb.num_queues=2 seems to have fixed the issue. (Two was the first value I tried, maybe other values other than 0 would work, too.)
> 
> In order to uphold POLA, should the igb driver maybe default to a conservative value for hw.igb.num_queues that may not deliver optimal performance, but at least works out of the box?

Or, better, make nmbclusters auto-tuning smarter, if any.
I mean, use more nmbclusters for machines with large amounts of memory.

Eugene Grosbein