Re: [hybi] Background info: Properties of sendfile()

[Roberto Peon <[e-mail]>]

sendfile() doesn't require sending the entire file.
At some frame size, the overhead due to interleaving sendfile() with write()
should be negligible.
I don't think that sendfile() is a good reason to require total message
length up-front.
I still like having the total-message-length whenever possible-- it does
allow for a quick decision about where to store or process the data.
-=R

On Fri, Aug 6, 2010 at 6:49 AM, Jack Moffitt <[e-mail]> wrote:

> > At least I've seen it. Haproxy happily forwards traffic at 10 Gbps
> > with only 25% of one CPU core on a 2.66 GHz Core2Duo using splice().
> > And some file sharing sites make a big use of it ! Without splice,
> > it hardly achieves 10 Gbps at 100% CPU.
>
> It's not clear how much of the benefit we'd lose with fixed size
> lengths (and therefore mandatory chunking). At this point, it seems
> that kind of data would be valuable.
>
> The tradeoff *seems* to be simple intermediaries versus
> sendfile()/splice() efficiency. If sendfile() is severely affected, it
> may make sense to make the intermediaries life slightly more
> complicated. If not, I think we keep their job simple.
>
> jack.
>