Re: pmap_extract(9) (was Re: xmd(4) (Re: XIP))

[Masao Uebayashi <uebayasi%tombi.co.jp@localhost>]

On Fri, Nov 05, 2010 at 05:36:53PM +0000, Eduardo Horvath wrote:
> On Fri, 5 Nov 2010, Masao Uebayashi wrote:
> 
> > On Mon, Nov 01, 2010 at 03:52:11PM -0700, Matt Thomas wrote:
> 
> > > Indeed.  Also consider that pmap's are designed to have to have
> > > fast V->P translations, using that instead of UVM makes a lot of
> > > sense.
> > 
> > How does locking works?
> > 
> > My understanding is page tables (per-process) are protected by
> > struct vm_map (per-process).  (Or moving toward it.)
> 
> No, once again this is MD.  For instance sparc64 uses compare and swap 
> instructions to manipulate page tables for lockless synchronization.

I don't like "it's MD, period" attitude.  That solves nothing.