From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx> Subject: slub: remove kmem_cache->reserved The reserved field was only used for embedding an rcu_head in the data structure. With the previous commit, we no longer need it. That lets us remove the 'reserved' argument to a lot of functions. Link: http://lkml.kernel.org/r/20180518194519.3820-16-willy@xxxxxxxxxxxxx Signed-off-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx> Acked-by: Christoph Lameter <cl@xxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: Jérôme Glisse <jglisse@xxxxxxxxxx> Cc: "Kirill A . Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Lai Jiangshan <jiangshanlai@xxxxxxxxx> Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx> Cc: Pekka Enberg <penberg@xxxxxxxxxx> Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/slub_def.h | 1 mm/slub.c | 41 ++++++++++++++++++------------------- 2 files changed, 20 insertions(+), 22 deletions(-) diff -puN include/linux/slub_def.h~slub-remove-kmem_cache-reserved include/linux/slub_def.h --- a/include/linux/slub_def.h~slub-remove-kmem_cache-reserved +++ a/include/linux/slub_def.h @@ -101,7 +101,6 @@ struct kmem_cache { void (*ctor)(void *); unsigned int inuse; /* Offset to metadata */ unsigned int align; /* Alignment */ - unsigned int reserved; /* Reserved bytes at the end of slabs */ unsigned int red_left_pad; /* Left redzone padding size */ const char *name; /* Name (only for display!) */ struct list_head list; /* List of slab caches */ diff -puN mm/slub.c~slub-remove-kmem_cache-reserved mm/slub.c --- a/mm/slub.c~slub-remove-kmem_cache-reserved +++ a/mm/slub.c @@ -316,16 +316,16 @@ static inline unsigned int slab_index(vo return (p - addr) / s->size; } -static inline unsigned int order_objects(unsigned int order, unsigned int size, unsigned int reserved) +static inline unsigned int order_objects(unsigned int order, unsigned int size) { - return (((unsigned int)PAGE_SIZE << order) - reserved) / size; + return ((unsigned int)PAGE_SIZE << order) / size; } static inline struct kmem_cache_order_objects oo_make(unsigned int order, - unsigned int size, unsigned int reserved) + unsigned int size) { struct kmem_cache_order_objects x = { - (order << OO_SHIFT) + order_objects(order, size, reserved) + (order << OO_SHIFT) + order_objects(order, size) }; return x; @@ -832,7 +832,7 @@ static int slab_pad_check(struct kmem_ca return 1; start = page_address(page); - length = (PAGE_SIZE << compound_order(page)) - s->reserved; + length = PAGE_SIZE << compound_order(page); end = start + length; remainder = length % s->size; if (!remainder) @@ -921,7 +921,7 @@ static int check_slab(struct kmem_cache return 0; } - maxobj = order_objects(compound_order(page), s->size, s->reserved); + maxobj = order_objects(compound_order(page), s->size); if (page->objects > maxobj) { slab_err(s, page, "objects %u > max %u", page->objects, maxobj); @@ -971,7 +971,7 @@ static int on_freelist(struct kmem_cache nr++; } - max_objects = order_objects(compound_order(page), s->size, s->reserved); + max_objects = order_objects(compound_order(page), s->size); if (max_objects > MAX_OBJS_PER_PAGE) max_objects = MAX_OBJS_PER_PAGE; @@ -3193,21 +3193,21 @@ static unsigned int slub_min_objects; */ static inline unsigned int slab_order(unsigned int size, unsigned int min_objects, unsigned int max_order, - unsigned int fract_leftover, unsigned int reserved) + unsigned int fract_leftover) { unsigned int min_order = slub_min_order; unsigned int order; - if (order_objects(min_order, size, reserved) > MAX_OBJS_PER_PAGE) + if (order_objects(min_order, size) > MAX_OBJS_PER_PAGE) return get_order(size * MAX_OBJS_PER_PAGE) - 1; - for (order = max(min_order, (unsigned int)get_order(min_objects * size + reserved)); + for (order = max(min_order, (unsigned int)get_order(min_objects * size)); order <= max_order; order++) { unsigned int slab_size = (unsigned int)PAGE_SIZE << order; unsigned int rem; - rem = (slab_size - reserved) % size; + rem = slab_size % size; if (rem <= slab_size / fract_leftover) break; @@ -3216,7 +3216,7 @@ static inline unsigned int slab_order(un return order; } -static inline int calculate_order(unsigned int size, unsigned int reserved) +static inline int calculate_order(unsigned int size) { unsigned int order; unsigned int min_objects; @@ -3233,7 +3233,7 @@ static inline int calculate_order(unsign min_objects = slub_min_objects; if (!min_objects) min_objects = 4 * (fls(nr_cpu_ids) + 1); - max_objects = order_objects(slub_max_order, size, reserved); + max_objects = order_objects(slub_max_order, size); min_objects = min(min_objects, max_objects); while (min_objects > 1) { @@ -3242,7 +3242,7 @@ static inline int calculate_order(unsign fraction = 16; while (fraction >= 4) { order = slab_order(size, min_objects, - slub_max_order, fraction, reserved); + slub_max_order, fraction); if (order <= slub_max_order) return order; fraction /= 2; @@ -3254,14 +3254,14 @@ static inline int calculate_order(unsign * We were unable to place multiple objects in a slab. Now * lets see if we can place a single object there. */ - order = slab_order(size, 1, slub_max_order, 1, reserved); + order = slab_order(size, 1, slub_max_order, 1); if (order <= slub_max_order) return order; /* * Doh this slab cannot be placed using slub_max_order. */ - order = slab_order(size, 1, MAX_ORDER, 1, reserved); + order = slab_order(size, 1, MAX_ORDER, 1); if (order < MAX_ORDER) return order; return -ENOSYS; @@ -3529,7 +3529,7 @@ static int calculate_sizes(struct kmem_c if (forced_order >= 0) order = forced_order; else - order = calculate_order(size, s->reserved); + order = calculate_order(size); if ((int)order < 0) return 0; @@ -3547,8 +3547,8 @@ static int calculate_sizes(struct kmem_c /* * Determine the number of objects per slab */ - s->oo = oo_make(order, size, s->reserved); - s->min = oo_make(get_order(size), size, s->reserved); + s->oo = oo_make(order, size); + s->min = oo_make(get_order(size), size); if (oo_objects(s->oo) > oo_objects(s->max)) s->max = s->oo; @@ -3558,7 +3558,6 @@ static int calculate_sizes(struct kmem_c static int kmem_cache_open(struct kmem_cache *s, slab_flags_t flags) { s->flags = kmem_cache_flags(s->size, flags, s->name, s->ctor); - s->reserved = 0; #ifdef CONFIG_SLAB_FREELIST_HARDENED s->random = get_random_long(); #endif @@ -5077,7 +5076,7 @@ SLAB_ATTR_RO(destroy_by_rcu); static ssize_t reserved_show(struct kmem_cache *s, char *buf) { - return sprintf(buf, "%u\n", s->reserved); + return sprintf(buf, "0\n"); } SLAB_ATTR_RO(reserved); _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
