Re: [PATCH 2/9] slab: makes clear_obj_pfmemalloc() just return store masked value

From: Christoph Lameter
Date: Fri Feb 14 2014 - 13:27:24 EST


On Fri, 14 Feb 2014, Joonsoo Kim wrote:

> clear_obj_pfmemalloc() takes the pointer to the object pointer as argument
> to store masked value back into this address.
> But this is useless, since we don't use this stored value anymore.
> All we need is just masked value. So makes clear_obj_pfmemalloc()
> just return masked value.

Could this be a bit more compact?

> @@ -215,9 +215,9 @@ static inline void set_obj_pfmemalloc(void **objp)
> return;
> }
>
> -static inline void clear_obj_pfmemalloc(void **objp)
> +static inline void *clear_obj_pfmemalloc(void *objp)
> {
> - *objp = (void *)((unsigned long)*objp & ~SLAB_OBJ_PFMEMALLOC);
> + return (void *)((unsigned long)objp & ~SLAB_OBJ_PFMEMALLOC);
> }

I dont think you need the (void *) cast here.

> /*
> @@ -810,7 +810,7 @@ static void *__ac_get_obj(struct kmem_cache *cachep, struct array_cache *ac,
> struct kmem_cache_node *n;
>
> if (gfp_pfmemalloc_allowed(flags)) {
> - clear_obj_pfmemalloc(&objp);
> + objp = clear_obj_pfmemalloc(objp);
> return objp;
> }

No need for objp. Just "return clear_obj_....


> @@ -833,7 +833,7 @@ static void *__ac_get_obj(struct kmem_cache *cachep, struct array_cache *ac,
> if (!list_empty(&n->slabs_free) && force_refill) {
> struct page *page = virt_to_head_page(objp);
> ClearPageSlabPfmemalloc(page);
> - clear_obj_pfmemalloc(&objp);
> + objp = clear_obj_pfmemalloc(objp);
> recheck_pfmemalloc_active(cachep, ac);
> return objp;

Same here?
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