From: Tom Herbert <therbert@google.com>
To: Stephen Hemminger <shemminger@vyatta.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 10:59:43 -0700 [thread overview]
Message-ID: <g2l65634d661004021059z94214a43v82409d15a0fb09b6@mail.gmail.com> (raw)
In-Reply-To: <20100402102650.5bdb5b52@nehalam>
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.
> Is there some way the hardware receive hash value could be used to
> steer to the receive CPU, then have the receive CPU find the Ethernet
> type field (eth_type_trans)?
> --
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next prev parent reply other threads:[~2010-04-02 17:59 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 [this message]
2010-04-02 18:54 ` Stephen Hemminger
2010-04-02 19:36 ` Eric Dumazet
2010-04-02 22:52 ` Stephen Hemminger
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