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From: Stephen Hemminger <shemminger@vyatta.com>
To: Tom Herbert <therbert@google.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>, netdev@vger.kernel.org
Subject: Re: Receive steering and hash and cache misses
Date: Fri, 2 Apr 2010 11:54:39 -0700	[thread overview]
Message-ID: <20100402115439.348575c9@nehalam> (raw)
In-Reply-To: <g2l65634d661004021059z94214a43v82409d15a0fb09b6@mail.gmail.com>

On Fri, 2 Apr 2010 10:59:43 -0700
Tom Herbert <therbert@google.com> wrote:

> On Fri, Apr 2, 2010 at 10:26 AM, Stephen Hemminger
> <shemminger@vyatta.com> wrote:
> >
> > Although Receive Packet Steering can use a hardware generated receive hash
> > the device driver still causes an unnecessary cache miss on the interrupt
> > processing CPU.  The current Ethernet network device driver receive processing
> > has the device driver calling eth_type_trans() which causes a the
> > interrupt CPU to read the received frame header.
> >
> 
> It should be possible to deduce the values set by eth_type_trans from
> the RX descriptor along with the RX hash.  I'll post the patch getting
> rxhash from bnx2x which does this.
> 

On sky2, I get only RSS, Checksum, and length from descriptor info.

  reply	other threads:[~2010-04-02 19:01 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-04-02 17:26 Receive steering and hash and cache misses Stephen Hemminger
2010-04-02 17:59 ` Tom Herbert
2010-04-02 18:54   ` Stephen Hemminger [this message]
2010-04-02 19:36     ` Eric Dumazet
2010-04-02 22:52       ` Stephen Hemminger

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