slab: remove kmem_bufctl_t (16025177) · Commits · 戴 / test

mm/slab.c

+11 −31

Original line number	Diff line number	Diff line
		@@ -163,27 +163,7 @@
		*/
		static bool pfmemalloc_active __read_mostly;

		/*
		* kmem_bufctl_t:
		*
		* Bufctl's are used for linking objs within a slab
		* linked offsets.
		*
		* This implementation relies on "struct page" for locating the cache &
		* slab an object belongs to.
		* This allows the bufctl structure to be small (one int), but limits
		* the number of objects a slab (not a cache) can contain when off-slab
		* bufctls are used. The limit is the size of the largest general cache
		* that does not use off-slab slabs.
		* For 32bit archs with 4 kB pages, is this 56.
		* This is not serious, as it is only for large objects, when it is unwise
		* to have too many per slab.
		* Note: This limit can be raised by introducing a general cache whose size
		* is less than 512 (PAGE_SIZE<<3), but greater than 256.
		*/

		typedef unsigned int kmem_bufctl_t;
		#define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-3)
		#define SLAB_LIMIT (((unsigned int)(~0U))-1)

		/*
		* struct slab
		@@ -197,7 +177,7 @@ struct slab {
		struct list_head list;
		void s_mem; / including colour offset */
		unsigned int inuse; /* num of objs active in slab */
		kmem_bufctl_t free;
		unsigned int free;
		};
		};

		@@ -613,7 +593,7 @@ static inline struct array_cache cpu_cache_get(struct kmem_cache cachep)

		static size_t slab_mgmt_size(size_t nr_objs, size_t align)
		{
		return ALIGN(sizeof(struct slab)+nr_objs*sizeof(kmem_bufctl_t), align);
		return ALIGN(sizeof(struct slab)+nr_objs*sizeof(unsigned int), align);
		}

		/*
		@@ -633,7 +613,7 @@ static void cache_estimate(unsigned long gfporder, size_t buffer_size,
		* slab is used for:
		*
		* - The struct slab
		* - One kmem_bufctl_t for each object
		* - One unsigned int for each object
		* - Padding to respect alignment of @align
		* - @buffer_size bytes for each object
		*
		@@ -658,7 +638,7 @@ static void cache_estimate(unsigned long gfporder, size_t buffer_size,
		* into account.
		*/
		nr_objs = (slab_size - sizeof(struct slab)) /
		(buffer_size + sizeof(kmem_bufctl_t));
		(buffer_size + sizeof(unsigned int));

		/*
		* This calculated number will be either the right
		@@ -2068,7 +2048,7 @@ static size_t calculate_slab_order(struct kmem_cache *cachep,
		* looping condition in cache_grow().
		*/
		offslab_limit = size - sizeof(struct slab);
		offslab_limit /= sizeof(kmem_bufctl_t);
		offslab_limit /= sizeof(unsigned int);

		if (num > offslab_limit)
		break;
		@@ -2309,7 +2289,7 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
		if (!cachep->num)
		return -E2BIG;

		slab_size = ALIGN(cachep->num * sizeof(kmem_bufctl_t)
		slab_size = ALIGN(cachep->num * sizeof(unsigned int)
		+ sizeof(struct slab), cachep->align);

		/*
		@@ -2324,7 +2304,7 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
		if (flags & CFLGS_OFF_SLAB) {
		/* really off slab. No need for manual alignment */
		slab_size =
		cachep->num * sizeof(kmem_bufctl_t) + sizeof(struct slab);
		cachep->num * sizeof(unsigned int) + sizeof(struct slab);

		#ifdef CONFIG_PAGE_POISONING
		/* If we're going to use the generic kernel_map_pages()
		@@ -2603,9 +2583,9 @@ static struct slab alloc_slabmgmt(struct kmem_cache cachep,
		return slabp;
		}

		static inline kmem_bufctl_t slab_bufctl(struct slab slabp)
		static inline unsigned int slab_bufctl(struct slab slabp)
		{
		return (kmem_bufctl_t *) (slabp + 1);
		return (unsigned int *) (slabp + 1);
		}

		static void cache_init_objs(struct kmem_cache *cachep,
		@@ -2684,7 +2664,7 @@ static void slab_put_obj(struct kmem_cache cachep, struct slab slabp,
		{
		unsigned int objnr = obj_to_index(cachep, slabp, objp);
		#if DEBUG
		kmem_bufctl_t i;
		unsigned int i;

		/* Verify that the slab belongs to the intended node */
		WARN_ON(page_to_nid(virt_to_page(objp)) != nodeid);

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