Re: Dropping NETIF_F_SG since no checksum feature.

• To: "Michael S. Tsirkin" <[email protected]>
• Subject: Re: Dropping NETIF_F_SG since no checksum feature.
• From: Roland Dreier <[email protected]>
• Date: Tue, 10 Oct 2006 20:33:46 -0700
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• Cc: Stephen Hemminger <[email protected]>, Linux Kernel Mailing List <[email protected]>, [email protected], [email protected], Roland Dreier <[email protected]>, "David S. Miller" <[email protected]>
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• In-reply-to: <[email protected]> (Michael S. Tsirkin's message of "Wed, 11 Oct 2006 02:26:56 +0200")
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    Michael> My guess was, an extra pass over data is likely to be
    Michael> expensive - dirtying the cache if nothing else. But I do
    Michael> plan to measure that, and see.

I don't get it -- where's the extra pass?  If you can't compute the
checksum on the NIC then you have to compute sometime it on the CPU
before passing the data to the NIC.

 - R.
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    • From: "Michael S. Tsirkin" <[email protected]>

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