Date: Wed, 02 Oct 1996 20:42:36 +0800 From: Peter Wemm <peter@spinner.dialix.com> To: Doug Rabson <dfr@render.com> Cc: Michael Hancock <michaelh@cet.co.jp>, Doug Rabson <dfr@freefall.freebsd.org>, freebsd-lite2@freefall.freebsd.org Subject: Re: cvs commit: src/sys TODO Message-ID: <199610021242.UAA00649@spinner.DIALix.COM> In-Reply-To: Your message of "Wed, 02 Oct 1996 13:00:33 %2B0100." <Pine.BSF.3.95.961002123950.10204L-100000@minnow.render.com>
next in thread | previous in thread | raw e-mail | index | archive | help
Doug Rabson wrote:
> On Wed, 2 Oct 1996, Michael Hancock wrote:
>
> > On Mon, 30 Sep 1996, Doug Rabson wrote:
> >
> > > dfr 96/09/30 07:20:31
> > >
> > > Branch: sys LITE2
> > > Added: sys TODO
> > > Log:
> > > This is a list of stuff that I think needs to be done before the lite2
> > > filesystem code is merged into -current. Feel free to add/remove/chang
e
> > > tasks.
> >
> > I noticed we're merging in simple_lock().
>
> I think that it would be a good idea to keep the simple_lock stuff since
> it seems to have the promise of multithreading the FS code in a future SMP
> system. It is almost certainly broken in the current tree since it is
> pretty tricky to test on a uniprocessor. There is some DEBUG code in
> kern_lock.c which looks as if it might be useful.
A couple of points:
- Kirk McKusick is reportedly putting some serious time into doing the
VFS's so that they are fully multithreaded, and he's apparently using the
lite2 kern_lock framework. We don't want to rule out the chance of using
his code should it become available and work. (I hear he's doing some
contracting for BSDI, I wonder if the FS work is what he's doing for them?
If so, it may not be available to us).
- I'm scratching my head over the SMP code's locking and am trying out
some experiments. It's looking reasonably promising that we can use the
kern_lock code to do internal kernel locking above the trap/exception/irq
layer, thus breaking the global mutex up. We can provide the raw boolean
locking primatives etc as appropriate. It's not really suitable code to
use it on the raw edge of the kernel entry points, but it looks like it
can be used above that.
In any case, it will certainly be interesting when the lite2 code meets
the smp code. :-)
Cheers,
-Peter
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199610021242.UAA00649>