Re: UVM aobj: Large VM objects.

[YAMAMOTO Takashi <yamt%mwd.biglobe.ne.jp@localhost>]

> On Mon, Mar 06, 2006 at 05:56:22PM +0900, YAMAMOTO Takashi wrote:
> > > On Mon, Mar 06, 2006 at 05:32:48PM +0900, YAMAMOTO Takashi wrote:
> > > > (although i doubt kernel_object really need to cover the entire region,)
> > > > making aobj 64-bit offset clean is a good idea.
> > > > 
> > > > however, i don't think long is appropriate here.
> > > > please introduce a 64-bit "page offset" type.
> > > > "typedef voff_t pgoff_t" should be fine.
> > > 
> > > Won't this make 32-bit ports slower?
> > 
> > which part of code are you talking about?
> 
> The original proposal was to make the u_pages member long. Are you
> proposing to make it a 64-bit type, or did I misunderstand something? And
> aren't 64-bit operations on 32-bit cpus slow?

given that fast path uses 64-bit types already, i don't think it will
have serious impacts.  i asked because i thought you knew the particular
piece of code which can be affected seriously.

YAMAMOTO Takashi