Re: [PATCH 00/12] Add kdbus implementation

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Thu, Oct 30, 2014 at 12:26:33AM +0100, Jiri Kosina wrote:
> On Thu, 30 Oct 2014, Jiri Kosina wrote:
> 
> > > > It seems to me that most of the highlight features from the cover letter 
> > > > can be "easily" (for certain definition of that word, of course) 
> > > > implemented in userspace (vmsplice(), sending fd through unix socket, user 
> > > > namespaces, UUID management, etc).
> > > 
> > > We have dbus in userspace today, but that requires extra copies of data,
> > 
> > But we can do zero-copy between processess for quite some time already, so 
> > what exactly is the issue here?
> > 
> > > and isn't easy, or even possible, to do some of the application-specific
> > > bus logic that kdbus provides.  
> > 
> > I unfortunately have absolutely no idea what should I imagine here.
> 
> Also, I think I have heard that binder is going out of staging now, right?

Yes, but that needs documentation, which I'm working on at the moment :)

> I admittedly have very limited understanding of both binder and kdbus, but 
> I guess that is the case for many folks. My understanding is that they are 
> providing very similar functionality, so explanation why we need *both* in 
> the kernel would be very interesting as well.

They do very different things, see this writeup I did a while ago about
the differences between them:
	http://kroah.com/log/blog/2014/01/15/kdbus-details/

thanks,

greg k-h