Re: [LSF/MM TOPIC ATTEND][RFD] ZUFS - Zero-copy User-mode File System

[Greg KH <gregkh@linuxfoundation.org>]

On Thu, Feb 01, 2018 at 08:59:18PM +0200, Boaz Harrosh wrote:
> > - The fundamental innovation of ZUFS is porting Solaris "doors" to Linux. A
> > "door" is a local RPC mechanism that stays on the same thread to reduce
> > scheduling overhead during calls to services provided by daemons on the local
> > system. Is there interest in building a generic "doors" facility in Linux?
> 
> People said I should look into the Binder project from Google. It is already
> in Kernel, and is used by Android. As I understand they have exactly such
> an object like you describe above. Combined with my thread-array it sounds
> like what I want.

There was a "libdoor" userspace library around a long time ago (I was
the GSoC mentor for it) to enable Solaris apps to be able to use the
"door" api on Linux.  Turns out no one really cared about it as the
number of Solaris-only applications seems to have dropped to almost 0.

And yes, if you want IPC that passes the cpu scheduler to the receiver,
use binder.  It's much faster and all of the old problems that used to
be present with it (scalability, security, etc.) seem to now be resolved
in the later kernel releases.

good luck!

greg k-h