Messages in this thread | | | Date | Wed, 10 Dec 2014 19:32:25 +0200 | Subject | Re: [PATCH 3/7] slub: Do not use c->page on free | From | Pekka Enberg <> |
| |
On Wed, Dec 10, 2014 at 7:08 PM, Christoph Lameter <cl@linux.com> wrote: >> > +{ >> > + long d = p - page->address; >> > + >> > + return d > 0 && d < (1 << MAX_ORDER) && d < (compound_order(page) << PAGE_SHIFT); >> > +} >> >> Can you elaborate on what this is doing? I don't really understand it. > > Checks if the pointer points to the slab page. Also it tres to avoid > having to call compound_order needlessly. Not sure if that optimization is > worth it.
Aah, it's the (1 << MAX_ORDER) optimization that confused me. Perhaps add a comment there to make it more obvious?
I'm fine with the optimization:
Reviewed-by: Pekka Enberg <penberg@kernel.org>
- Pekka
| |