Re: [PATCH 09/16] slab: use __GFP_COMP flag for allocating slab pages

From: Joonsoo Kim
Date: Fri Aug 23 2013 - 02:55:37 EST


On Thu, Aug 22, 2013 at 06:00:56PM +0000, Christoph Lameter wrote:
> On Thu, 22 Aug 2013, Joonsoo Kim wrote:
>
> > If we use 'struct page' of first page as 'struct slab', there is no
> > advantage not to use __GFP_COMP. So use __GFP_COMP flag for all the cases.
>
> Ok that brings it in line with SLUB and SLOB.

Yes!

>
> > @@ -2717,17 +2701,8 @@ static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
> > static void slab_map_pages(struct kmem_cache *cache, struct slab *slab,
> > struct page *page)
> > {
> > - int nr_pages;
> > -
> > - nr_pages = 1;
> > - if (likely(!PageCompound(page)))
> > - nr_pages <<= cache->gfporder;
> > -
> > - do {
> > - page->slab_cache = cache;
> > - page->slab_page = slab;
> > - page++;
> > - } while (--nr_pages);
> > + page->slab_cache = cache;
> > + page->slab_page = slab;
> > }
>
> And saves some processing.

Yes!

--
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/