Re: [PATCH 3/3] slub: add hooks for kmemcheck

[Christoph Lameter <clameter@sgi.com>]

On Sat, 19 Apr 2008, Vegard Nossum wrote:

> index f62caaa..d5505b1 100644
> --- a/include/linux/slab.h
> +++ b/include/linux/slab.h
> @@ -29,6 +29,13 @@
>  #define SLAB_MEM_SPREAD		0x00100000UL	/* Spread some memory over cpuset */
>  #define SLAB_TRACE		0x00200000UL	/* Trace allocations and frees */
>  
> +#ifdef CONFIG_KMEMCHECK
> +/* Don't track use of uninitialized memory */
> +# define SLAB_NOTRACK		0x00400000UL
> +#else
> +# define SLAB_NOTRACK		0
> +#endif
> +

It maybe easier to just avoid the #ifdef. The other debug flags also only 
have a function if certain kernel config options are set.

> +#ifdef CONFIG_KMEMCHECK
> +struct page *kmemcheck_allocate_slab(struct kmem_cache *s,
> +	gfp_t flags, int node, int pages);
> +void kmemcheck_free_slab(struct kmem_cache *s, struct page *page, int pages);
> +
> +void kmemcheck_slab_alloc(struct kmem_cache *s, gfp_t gfpflags, void *object);
> +void kmemcheck_slab_free(struct kmem_cache *s, void *object);
> +#else
> +static inline struct page *kmemcheck_allocate_slab(struct kmem_cache *s,
> +	gfp_t flags, int node, int pages) { return NULL; }
> +static inline void kmemcheck_free_slab(struct kmem_cache *s,
> +	struct page *page, int pages) { }
> +static inline void kmemcheck_slab_alloc(struct kmem_cache *s,
> +	gfp_t gfpflags, void *object) { }
> +static inline void kmemcheck_slab_free(struct kmem_cache *s, void *object) { }
> +#endif /* CONFIG_KMEMCHECK */
> +

Should this not go into some kmemcheck.h file?

>  	}
>  
> +	if (kmemcheck_page_is_tracked(page) && !(s->flags & SLAB_NOTRACK)) {
> +		kmemcheck_free_slab(s, page, pages);
> +		return;
> +	}
> +
> +	__ClearPageSlab(page);
> +

Why is __ClearPageSlab moved?

> @@ -2449,12 +2462,10 @@ static int __init setup_slub_nomerge(char *str)
>  __setup("slub_nomerge", setup_slub_nomerge);
>  
>  static struct kmem_cache *create_kmalloc_cache(struct kmem_cache *s,
> -		const char *name, int size, gfp_t gfp_flags)
> +	const char *name, int size, gfp_t gfp_flags, unsigned int flags)

The second flags parameter is always 0?