Re: CVS commit: [yamt-lazymbuf] src/sys/arch/amd64/include

[Joerg Sonnenberger <joerg%britannica.bec.de@localhost>]

On Wed, Jan 23, 2008 at 11:09:23PM +0900, YAMAMOTO Takashi wrote:
> in_cksum is often used for the header portion of a chain.
> ie. not the whole chain.

Current usage:
bridge(4): IP header checksum
ip_fastforward: IP header checksum
igmp_input: full packet, should be switched to the generalised version later.
igmp_sendpkt: partial packet, should be switched as well
tcp4_segment: header only
carp: full packet (one exception, but that should be fixed)
icmp_input: header only
icmp_send: full
ip_input: IP header checksum
ip_mroute: IP header checksum (can be optimised, I think), full in some
other cases
ip_output: IP header sum
tcp_respond: full packet
udp6_output: full packet
ipsec4_encapsulate: header

in4_cksum and in6_cksum seem to be used almost exclusively with the full
header. I haven't checked which of the above are in the input path and
would benefit from lazy mbuf chains. I don't think those in the output
path normally do. So what again was the justification for the added
complexity?

Joerg