cvs commit: src/sys/vm vm_fault.c

[Alan Cox]

On Sat, Aug 21, 2004 at 06:59:39PM -0400, Brian Fundakowski Feldman wrote:
> On Sat, Aug 21, 2004 at 07:20:21PM +0000, Alan Cox wrote:
> > alc         2004-08-21 19:20:21 UTC
> > 
> >   FreeBSD src repository
> > 
> >   Modified files:
> >     sys/vm               vm_fault.c 
> >   Log:
> >   Further reduce the use of Giant by vm_fault(): Giant is held only when
> >   manipulating a vnode, e.g., calling vput().  This reduces contention for
> >   Giant during many copy-on-write faults, resulting in some additional
> >   speedup on SMPs.
> >   
> >   Note: debug_mpsafevm must be enabled for this optimization to take effect.
> 
> This is very broken.  See included first attempt at fixing it without
> regard for actually trying to reimplement debug.mpsafenet for vnodes.
> 

Can you please explain what is broken?

Alan