Starting the kdbus discussions

[Greg KH]

On Tue, Jan 14, 2014 at 11:08:11AM +0100, Tim Sander wrote:
> Hi
> > Speed isn't the main benefit, see all of the other comments about why
> > this work was done for those reasons.  But, it will be nice if it is
> > faster.  
> Huh, i thought speed was the main reason for moving into kernel space. 
> The context switches imposed by dbus-deamon really hurt latency.
> Just out of interest: could you point to somewhere what you main design 
> targets were instead?

Please see the LCA talk about kdbus for a description of the primary
design goals and why this was done in the kernel (don't have a link to
it at the moment, should be easy to google for...)

> > I have heard reports of orders-of-magnitude speed increases on
> > some workloads / benchmarks, but as I've never run them, and everyone's
> > processor / system / workload for dbus is different, I encourage others
> > to run their own tests if they really care about dbus performance
> > issues.
> > 
> > Hint, almost no one cares about dbus performance, except people with
> > really underpowered processors abusing dbus for things it was never
> > originally intended to do.
> Does arm11 with 533 Mhz count?

Depends on how bad you are abusing dbus messages in your userspace code :)

thanks,

greg k-h