Messages in this thread | | | Date | Mon, 15 Dec 2014 17:03:38 +0900 | From | Joonsoo Kim <> | Subject | Re: [PATCH 3/7] slub: Do not use c->page on free |
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On Wed, Dec 10, 2014 at 10:30:20AM -0600, Christoph Lameter wrote: > Avoid using the page struct address on free by just doing an > address comparison. That is easily doable now that the page address > is available in the page struct and we already have the page struct > address of the object to be freed calculated. > > Signed-off-by: Christoph Lameter <cl@linux.com> > > Index: linux/mm/slub.c > =================================================================== > --- linux.orig/mm/slub.c 2014-12-09 12:25:45.770405462 -0600 > +++ linux/mm/slub.c 2014-12-09 12:25:45.766405582 -0600 > @@ -2625,6 +2625,13 @@ slab_empty: > discard_slab(s, page); > } > > +static bool same_slab_page(struct kmem_cache *s, struct page *page, void *p) > +{ > + long d = p - page->address; > + > + return d > 0 && d < (1 << MAX_ORDER) && d < (compound_order(page) << PAGE_SHIFT); > +} > +
Somtimes, compound_order() induces one more cacheline access, because compound_order() access second struct page in order to get order. Is there any way to remove this?
Thanks.
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