Re: [PATCH] Make slab use alloc_pages directly

[Manfred Spraul]

Matthew Wilcox wrote:

> __get_free_pages() calls alloc_pages, finds the page_address() and
> throws away the struct page *.  Slab then calls virt_to_page to get it
> back again.  Much more efficient for slab to call alloc_pages itself,
> as well as making the NUMA and non-NUMA cases more similarr to each other.
>
> Signed-off-by: Matthew Wilcox <matthew@xxxxxx>
>
>  
Signed-off-by: Manfred Spraul <manfred@xxxxxxxxxxxxxxxx>

> Index: linux-2.6/mm/slab.c
> ===================================================================
> RCS file: /var/cvs/linux-2.6/mm/slab.c,v
> retrieving revision 1.29
> diff -u -p -r1.29 slab.c
> --- linux-2.6/mm/slab.c	12 Jan 2005 20:18:07 -0000	1.29
> +++ linux-2.6/mm/slab.c	24 Jan 2005 16:47:02 -0000
> @@ -894,16 +894,13 @@ static void *kmem_getpages(kmem_cache_t 
>
> 	flags |= cachep->gfpflags;
> 	if (likely(nodeid == -1)) {
> -		addr = (void*)__get_free_pages(flags, cachep->gfporder);
> -		if (!addr)
> -			return NULL;
> -		page = virt_to_page(addr);
> +		page = alloc_pages(flags, cachep->gfporder);
> 	} else {
> 		page = alloc_pages_node(nodeid, flags, cachep->gfporder);
> -		if (!page)
> -			return NULL;
> -		addr = page_address(page);
> 	}
> +	if (!page)
> +		return NULL;
> +	addr = page_address(page);
>
> 	i = (1 << cachep->gfporder);
> 	if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
>
>  

-
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/