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From: Matthew Hall <mhall@mhcomputing.net>
To: "Martin Drašar" <drasar@ics.muni.cz>
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] Broken RSS hash computation on Intel 82574L
Date: Tue, 1 Sep 2015 07:47:26 -0700	[thread overview]
Message-ID: <20150901144726.GA30421@mhcomputing.net> (raw)
In-Reply-To: <55E5B81E.8010601@ics.muni.cz>

On Tue, Sep 01, 2015 at 04:37:18PM +0200, Martin Drašar wrote:
> Dne 1.9.2015 v 15:45 De Lara Guarch, Pablo napsal(a):
> > 82574L NIC uses em PMD, which does not support more than 1 queue.
> > Therefore RSS is disabled in the NIC and then you cannot have RSS hashes.
> > 
> > Thanks,
> > Pablo
> 
> Hi Pablo,
> 
> that is an interesting information. I read the rationale in em_ethdev.c
> and I was wondering, what would have to be done to enable RSS hash
> computation on that card. I can live with just one RX queue, but hashes
> would help me a lot. The computer which is using those NICs is not that
> powerful and every bit of offloaded computation counts...
> 
> Thanks,
> Martin

RSS calculations are used to direct packets across multiple RX queues. With 
only one RX queue it cannot possibly increase performance by enabling it.

Matthew.

  reply	other threads:[~2015-09-01 14:48 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-08-31 12:15 Martin Drašar
2015-09-01 13:45 ` De Lara Guarch, Pablo
2015-09-01 14:37   ` Martin Drašar
2015-09-01 14:47     ` Matthew Hall [this message]
2015-09-01 14:50       ` Avi Kivity
2015-09-01 15:00         ` Martin Drašar
2015-09-01 15:19       ` Jim Thompson

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