Re: [PATCH] TCP Zero Copy for mmapped files

From: Larry McVoy (lm@bitmover.com)
Date: Thu Jan 02 2003 - 20:01:07 EST


> It might be a bit difficult to convert all applications to
> sendfile. Especially those for which you don't have the
> source code.

And the list of applications which do

        sock = socket(...);
        map = mmap(...);
        write(sock, map, bytes);

are? There are not very many that I know of and if you look carefully
at the bandwidth graphs in LMbench you'll see why. There is a cross
over point where mmap becomes cheaper but it used to be around 16-64K.
I don't know what it is now, I doubt it's moved much. I can check if
you really want.

-- 
---
Larry McVoy            	 lm at bitmover.com           http://www.bitmover.com/lm 
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