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Subject: Re: [PATCH] net: mv643xx_eth: Add GRO support
From: Eric Dumazet <eric.dumazet@gmail.com>
To: Willy Tarreau <w@1wt.eu>
Date: Thu, 11 Apr 2013 09:10:44 -0700
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Cc: Andrew Lunn <andrew@lunn.ch>, Jason Cooper <jason@lakedaemon.net>,
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 Soeren Moch <smoch@web.de>, Paul Mackerras <paulus@samba.org>,
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On Thu, 2013-04-11 at 18:02 +0200, Willy Tarreau wrote:

> OK, that makes sense indeed, I didn't think about this case. All
> I remember was that the old call achieved a higher packet rate
> than napi_gro_receive, but it was on an older kernel and I can't
> be more specifics after several months :-/

Its probably true that the GRO handler consumes more cpu for packets
that cant be aggregated in the end.

Thats a trade off, and maybe we could add in the core stack a device
feature to instruct gro handler to do a short cut for packets with no
checksum. Or better a sysctl so that a static_branch can be used.