Re: [PATCH] TCP Zero Copy for mmapped files

[Alan Cox]

On Thu, 2003-01-02 at 23:16, David S. Miller wrote:    
>    It depends how predictable your content is. With a 64bit box and a porn
>    server its probably quite tidy
>    
> Let's say you have infinite VM (which is what 64-bit almost is :) then
> the cost is setting up all of these useless VMAs for each and every
> file (which is a 1 time cost, ok), and also the VMA lookup each
> write() call.
> 
> With sendfile() all of this goes straight to the page cache directly
> without a VMA lookup.

With a nasty unpleasant splat the moment you do modification on the
content at all. For static objects sendfile is certainly superior,