[Click] Re?: Re: Kernel mode with a recent kernel

[Luigi Rizzo]

On Fri, Dec 16, 2011 at 10:54:06PM +0200, Beyers Cronje wrote:
> According to figure 5
> http://info.iet.unipi.it/~luigi/netmap/20110729-rizzo-infocom.pdf  there
> seems to be a significant improvement over netmapcap using native netmap
> (7500kpps vs 9660kpps), so this sounds like a good idea.

in terms of time it is only 20ns per packet :)

Surely every little improvement counts, but probably it is more
useful to extend the libpcap library to attach to individual rings,
so you can run multiple threads in parallel without contention.
It's a trivial change (the ring index can be part of the device
name).

To use efficiently the native API, click should use the buffers
allocated by netmap instead of its own. I guess the in-kernel
click does the same, using sk_buffs instead of allocating memory ?

cheers
luigi

> 
> On Fri, Dec 16, 2011 at 9:08 PM, Eddie Kohler <ekohler at gmail.com> wrote:
> 
> > Luigi,
> >
> > As you know I think this is awesome.
> >
> > Should we start working on a direct linkup between Click and netmap, rather
> > than using libpcap as an intermediate?
> >
> > Eddie
> >
> >
> > On 12/16/2011 10:32 AM, Luigi Rizzo wrote:
> > > On Fri, Dec 16, 2011 at 03:57:00PM +0100, Fabrice Schuler wrote:
> > >> Hi Eddy,
> > >>
> > >> Thanks for your answer.
> > >>
> > >> In a first time, we could probably only use kernel mode without
> > polling, so patchless click could be fine. But on a longer run, I would say
> > that yes, we will need polling mode.
> > >> I will try patchless mode in a first time, and will still try to work
> > to use polling in a second time.
> > >
> > > If you are interested in polling because of performance, you should
> > > really consider using click-userspace with netmap (currently on
> > > FreeBSD, but linux support is really close now)
> > >
> > > http://info.iet.unipi.it/~luigi/netmap/
> > >
> > > In our tests it seems to beat in-kernel click by a factor of 2,
> > > for I/O intensive tasks (where polling makes the difference).
> > >
> > > http://info.iet.unipi.it/~luigi/netmap/20110729-rizzo-infocom.pdf
> > >
> > > cheers
> > > luigi
> > > _______________________________________________
> > > click mailing list
> > > click at amsterdam.lcs.mit.edu
> > > https://amsterdam.lcs.mit.edu/mailman/listinfo/click
> > _______________________________________________
> > click mailing list
> > click at amsterdam.lcs.mit.edu
> > https://amsterdam.lcs.mit.edu/mailman/listinfo/click
> >