Re: SLUB: The unqueued Slab allocator

David Miller
2007-02-22T08:58:26Z

From: Christoph Lameter <clameter@sgi.com>
Date: Wed, 21 Feb 2007 23:00:30 -0800 (PST)

> +#ifdef CONFIG_ZONE_DMA
> +static struct kmem_cache *kmalloc_caches_dma[KMALLOC_NR_CACHES];
> +#endif

Therefore.

> +static struct kmem_cache *get_slab(size_t size, gfp_t flags)
> +{
...
> + s = kmalloc_caches_dma[index];
> + if (s)
> + return s;
> +
> + /* Dynamically create dma cache */
> + x = kmalloc(sizeof(struct kmem_cache), flags & ~(__GFP_DMA));
> +
> + if (!x)
> + panic("Unable to allocate memory for dma cache\n");
> +
> +#ifdef KMALLOC_EXTRA
> + if (index <= KMALLOC_SHIFT_HIGH - KMALLOC_SHIFT_LOW)
> +#endif
> + realsize = 1 << index;
> +#ifdef KMALLOC_EXTRA
> + else if (index == KMALLOC_EXTRAS)
> + realsize = 96;
> + else
> + realsize = 192;
> +#endif
> +
> + s = create_kmalloc_cache(x, "kmalloc_dma", realsize);
> + kmalloc_caches_dma[index] = s;
> + return s;
> +}

All of that logic needs to be protected by CONFIG_ZONE_DMA too.

I noticed this due to a build failure on sparc64 with this patch.