RE: [net-next 08/11] e1000e: add Receive Packet Steering (RPS) support

On Fri, 2012-01-06 at 17:22 +0000, Allan, Bruce W wrote:

quoted

-----Original Message-----
From: Ben Hutchings [mailto:bhutchings@solarflare.com]
Sent: Tuesday, January 03, 2012 1:05 PM
To: Kirsher, Jeffrey T
Cc: davem@davemloft.net; Allan, Bruce W; netdev@vger.kernel.org;
gospo@redhat.com; sassmann@redhat.com
Subject: Re: [net-next 08/11] e1000e: add Receive Packet Steering (RPS) support

On Tue, 2012-01-03 at 11:19 -0800, Jeff Kirsher wrote:

quoted

From: Bruce Allan <redacted>

Enable RPS by default.  Disallow jumbo frames when both receive checksum
and receive hashing are enabled because the hardware cannot do both IP
payload checksum (enabled when receive checksum is enabled when using
packet split which is used for jumbo frames) and provide RSS hash at the
same time.

[...]

This doesn't seem to have much to do with RPS.  RPS can use a hardware
hash but doesn't require it.

You should also implement the ethtool command to query flow hashing
behaviour (ETHTOOL_GRXFH command, get_rxnfc operation).

Ben.

--
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

Thanks for the feedback Ben.  One question: is the data returned from
an ETHTOOL_GRXFH command with the get_rxnfc operation supposed to be
the default for the device or the current setting?

It's supposed to return the current setting.  There's no way to find out
the default once the behaviour has been changed.

Ben.

-- 
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.