Re: sendfile+zerocopy: fairly sexy (nothing to do with ECN)

[Rick Jones]

> I'll give this a shot later. Can you try with the sendfiled-ttcp?
> http://www.cyberus.ca/~hadi/ttcp-sf.tar.gz

I guess I need to "leverage" some bits for netperf :)

WRT getting data with links that cannot saturate a system, having
something akin to the netperf service demand measure can help. Nothing
terribly fancy - simply a conversion of the CPU utilization and
throughput to a microseconds of CPU to transfer a KB of data. 

As for CKO and avoiding copies and such, if past experience is any guide
(ftp://ftp.cup.hp.com/dist/networking/briefs/copyavoid.ps) you get a
very nice synergistic effect once the last "access" of data is removed.
CKO gets you say 10%, avoiding the copy gets you say 10%, but doing both
at the same time gets you 30%.

rick jones
http://www.netperf.org/
-- 
ftp://ftp.cup.hp.com/dist/networking/misc/rachel/
these opinions are mine, all mine; HP might not want them anyway... :)
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