Wrong
Why do people even bother playing along with him 8)
> addition to a file handle. The TCP stack sends the file data directly from
> the file system cache as a 0-copy send. The user buffers are also sent with
> the file data, and are not copied from user space, but locked into physical
> memory for the duration of the send.
BTW I hope Solaris didnt do that, there is a classic sendfile machine
destroying attack when you use a lot of slow connections to jam a machine
up with locked down pages. Fun for all the family
Similarly most of his other arguments are based on highly theoretical views
of computing. One thing writing a real OS instead of writing about it teaches
people is that 99% of OS theory is complete and utter crud.
Zero copy is a good example. For many things zero copy actually reduces
performance, especially on SMP machines, due to the amount of memory handling
work on the page locking.
That is why many OS's only do sendfile() based zero copy.
Alan
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