Re: [PATCH] nommu: fix kobjsize() for SLOB and SLUB

Paul Mundt
2008-06-02T07:03:41Z

On Mon, Jun 02, 2008 at 09:58:01AM +0300, Pekka Enberg wrote:
> Hi Paul,
>
> On Mon, Jun 2, 2008 at 9:50 AM, Paul Mundt <lethal@linux-sh.org> wrote:
> > Well, with that modified version of your patch I posted, even if your
> > previous PG_slab patches aren't applied, kobjsize() doesn't behave any
> > worse than it presently does in terms of object size accuracy.
> >
> > In short: PG_slab doesn't get set and ksize() is never called, so we get
> > the same degree of accuracy as the existing implementation, and the
> > oopses get fixed (and the comments are still accurate, too!). So I think
> > it's worth applying. Verified on all of SLUB/SLOB/SLAB.
>
> Agreed. Can you send this to Andrew?
>
> Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
>
Will do!

> On Mon, Jun 2, 2008 at 9:50 AM, Paul Mundt <lethal@linux-sh.org> wrote:
> > As for the call-site question, perhaps I'm misunderstanding your
> > question. alloc_vfsmnt() is the first to call kmem_cache_zalloc() during
> > boot-up on my system, but I'm not sure what relevance this has to
> > anything? Accurately measuring kmem_cache_alloc() and static allocations
> > is going to need quite a bit more of a re-think, but that's out of scope
> > for 2.6.26. Presently I'd rather have my system booting first :-)
>
> David already mentioned some (most?) of the kobjsize() calls can go
> away and I think we should pursue that for 2.6.27.

Ah, the kobjsize() calls is what you were getting at. Yes, getting rid of
those would be a good plan. I'll start looking at that more in-depth once
I've got some of my other 2.6.27 stuff out of the way. That's definitely
one interface that needs to be killed off with extreme prejudice..