Subject: Re: Early SPECWeb99 results on 2.5.33 with TSO on e1000

From: David Woodhouse <[email-masked]>
Date: Tue, 17 Sep 2002 00:03:19 +0100

[email-masked] said:
> >   Er, surely the same goes for sys_sendfile? Why have a new system
> >   call rather than just swapping the 'in' and 'out' fds?

> There is an assumption that one is a linear stream of output (in this
> case a socket) and the other one is a page cache based file.

That's an implementation detail and it's not clear we should be exposing it 
to the user. It's not entirely insane to contemplate socket->socket or 
file->file sendfile either -- would we invent new system calls for those 
too? File descriptors are file descriptors.

> It would be nice to extend sys_sendfile to work properly in both ways
> in a manner that Linus would accept, want to work on that? 

Yeah -- I'll add it to the TODO list. Scheduled for some time in 2007 :)

More seriously though, I'd hope that whoever implemented what you call 
'sys_receivefile' would solve this issue, as 'sys_receivefile' isn't really 
useful as anything more than a handy nomenclature for describing the 
process in question.

--
dwmw2