Re: [PATCH 6/13] maps: Move the page walker code to lib/

[Nick Piggin]

Matt Mackall wrote:
> On Wed, Apr 04, 2007 at 03:50:56PM +1000, Nick Piggin wrote:
>
> > Matt Mackall wrote:
> >
> > > On Wed, Apr 04, 2007 at 01:51:37PM +1000, Nick Piggin wrote:
> > >
> > >
> > > > Matt Mackall wrote:
> > > >
> > > >
> > > > > Move the page walker code to lib/
> > > > >
> > > > > This lets it get shared outside of proc/ and linked in only when
> > > > > needed.
> > > >
> > > > I think it would be better in mm/.
> > >
> > >
> > > I originally was looking at putting it in mm/memory.c and possibly
> >
> > Just put it in its own file in mm/ rather than its own file in lib.
> > lib should be for almost-standalone stuff, IMO (ie. only using basic
> > kernel functionality).
>
>
> Arguably that's what lib/ should be for, but it's currently largely

I disagree. There is code everywhere that exists to provide some
functionality via an API to other parts of the kernel. You don't
think mm/page_alloc.c should go in lib/?

> used to avoid linking in unused code without adding more hair to
> Kconfig. Which is what I'm trying to do here.

Well if you're doing a nice big reorganisation and jumble, then
why would you worry about a few lines in Kconfig?

> > Apart from these users outside mm/, I don't see much point in converting
> > things over. The page table walking API we have now is neat and simple.
> > It takes a few lines of code, but is it a big problem?
>
>
> I don't think it really qualifies as either neat or simple. It may be
> about as neat as walking a heterogenous tree with an inconsistent
> naming scheme can be, but it's still a headache. A maze of twisty
> little passages, all slightly different.

All page table range walking code should be the same.
It is a simple template to use to walk a range of ptes. It is
a headache outside mm/, sure, but not because of its incredible
complexity.

--
SUSE Labs, Novell Inc.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/