fdclone KPI

[John Baldwin]

On Wednesday 09 April 2008 03:29:18 pm Kostik Belousov wrote:
> On Wed, Apr 09, 2008 at 11:25:46AM -0400, John Baldwin wrote:
> > On Wednesday 09 April 2008 12:01:44 am Kostik Belousov wrote:
> > > On Tue, Apr 08, 2008 at 04:09:30PM -0700, Rick Hunnicutt wrote:
> > > > I'm curious if someone can tell me why the fdclone KPI was not 
included in 
> > the 7.0 release?
> > > 
> > > Because it got no
> > > - review;
> > > - interest from the driver authors;
> > > - agreement that this is the way to go.
> > 
> > Oof, where is the patch?  I think it is definitely easier for people to 
use 
> > than devfs cloning when all that is needed is per-instance data.  I would 
use 
> > it in the ipmi(4) driver and the nvidia graphics driver would likely 
prefer 
> > it to devfs cloning as well.
> 
> http://people.freebsd.org/~kib/misc/fdclone.10.patch
> http://people.freebsd.org/~kib/misc/fclone.c
> 
> The patch was developed before the struct file becomes lockless. The link
> above contains the mechanically updated patch, that was given one
> smoke-test run.
> 
> fclone.c is the trivial driver that utilizes the new KPI.

Oh, so this still does devfs style cloning just under the covers.  Hmm, I 
thought you had actually added a new 'void *f_foo' member to struct file.

-- 
John Baldwin