Re: [PATCH v2] tcp: splice as many packets as possible at once

[Roland Dreier]

 > And the arbitrary choice of 9k for jumbo frames was total crap too.
 > It's clear that no hardware designer was involved in the process.
 > They have to stuff 16kB of RAM on a NIC to use only 9. And we need
 > to allocate 3 pages for slightly more than 2. 7.5 kB would have been
 > better in this regard.

9K was not totally arbitrary.  The CRC used for checksumming ethernet
packets has a probability of undetected errors that goes up about
11-thousand something bytes.  So the real limit is ~11000 bytes, and I
believe ~9000 was chosen to be able to carry 8K NFS payloads + all XDR
and transport headers without fragmentation.

 - R.
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