From: Alexey Dobriyan <adobriyan@xxxxxxxxx> Subject: slab, slub, slob: convert slab_flags_t to 32-bit struct kmem_cache::flags is "unsigned long" which is unnecessary on 64-bit as no flags are defined in the higher bits. Switch the field to 32-bit and save some space on x86_64 until such flags appear: add/remove: 0/0 grow/shrink: 0/107 up/down: 0/-657 (-657) function old new delta sysfs_slab_add 720 719 -1 ... check_object 699 676 -23 [akpm@xxxxxxxxxxxxxxxxxxxx: fix printk warning] Link: http://lkml.kernel.org/r/20171021100635.GA8287@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx> Acked-by: Pekka Enberg <penberg@xxxxxxxxxx> Cc: Christoph Lameter <cl@xxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/slab.h | 44 ++++++++++++++++++++-------------------- include/linux/types.h | 2 - mm/slab.c | 4 +-- mm/slub.c | 6 ++--- 4 files changed, 28 insertions(+), 28 deletions(-) diff -puN include/linux/slab.h~slab-slub-slob-convert-slab_flags_t-to-32-bit include/linux/slab.h --- a/include/linux/slab.h~slab-slub-slob-convert-slab_flags_t-to-32-bit +++ a/include/linux/slab.h @@ -22,19 +22,19 @@ * The ones marked DEBUG are only valid if CONFIG_DEBUG_SLAB is set. */ /* DEBUG: Perform (expensive) checks on alloc/free */ -#define SLAB_CONSISTENCY_CHECKS ((slab_flags_t __force)0x00000100UL) +#define SLAB_CONSISTENCY_CHECKS ((slab_flags_t __force)0x00000100U) /* DEBUG: Red zone objs in a cache */ -#define SLAB_RED_ZONE ((slab_flags_t __force)0x00000400UL) +#define SLAB_RED_ZONE ((slab_flags_t __force)0x00000400U) /* DEBUG: Poison objects */ -#define SLAB_POISON ((slab_flags_t __force)0x00000800UL) +#define SLAB_POISON ((slab_flags_t __force)0x00000800U) /* Align objs on cache lines */ -#define SLAB_HWCACHE_ALIGN ((slab_flags_t __force)0x00002000UL) +#define SLAB_HWCACHE_ALIGN ((slab_flags_t __force)0x00002000U) /* Use GFP_DMA memory */ -#define SLAB_CACHE_DMA ((slab_flags_t __force)0x00004000UL) +#define SLAB_CACHE_DMA ((slab_flags_t __force)0x00004000U) /* DEBUG: Store the last owner for bug hunting */ -#define SLAB_STORE_USER ((slab_flags_t __force)0x00010000UL) +#define SLAB_STORE_USER ((slab_flags_t __force)0x00010000U) /* Panic if kmem_cache_create() fails */ -#define SLAB_PANIC ((slab_flags_t __force)0x00040000UL) +#define SLAB_PANIC ((slab_flags_t __force)0x00040000U) /* * SLAB_TYPESAFE_BY_RCU - **WARNING** READ THIS! * @@ -73,50 +73,50 @@ * Note that SLAB_TYPESAFE_BY_RCU was originally named SLAB_DESTROY_BY_RCU. */ /* Defer freeing slabs to RCU */ -#define SLAB_TYPESAFE_BY_RCU ((slab_flags_t __force)0x00080000UL) +#define SLAB_TYPESAFE_BY_RCU ((slab_flags_t __force)0x00080000U) /* Spread some memory over cpuset */ -#define SLAB_MEM_SPREAD ((slab_flags_t __force)0x00100000UL) +#define SLAB_MEM_SPREAD ((slab_flags_t __force)0x00100000U) /* Trace allocations and frees */ -#define SLAB_TRACE ((slab_flags_t __force)0x00200000UL) +#define SLAB_TRACE ((slab_flags_t __force)0x00200000U) /* Flag to prevent checks on free */ #ifdef CONFIG_DEBUG_OBJECTS -# define SLAB_DEBUG_OBJECTS ((slab_flags_t __force)0x00400000UL) +# define SLAB_DEBUG_OBJECTS ((slab_flags_t __force)0x00400000U) #else -# define SLAB_DEBUG_OBJECTS ((slab_flags_t __force)0x00000000UL) +# define SLAB_DEBUG_OBJECTS 0 #endif /* Avoid kmemleak tracing */ -#define SLAB_NOLEAKTRACE ((slab_flags_t __force)0x00800000UL) +#define SLAB_NOLEAKTRACE ((slab_flags_t __force)0x00800000U) /* Don't track use of uninitialized memory */ #ifdef CONFIG_KMEMCHECK -# define SLAB_NOTRACK ((slab_flags_t __force)0x01000000UL) +# define SLAB_NOTRACK ((slab_flags_t __force)0x01000000U) #else -# define SLAB_NOTRACK ((slab_flags_t __force)0x00000000UL) +# define SLAB_NOTRACK 0 #endif /* Fault injection mark */ #ifdef CONFIG_FAILSLAB -# define SLAB_FAILSLAB ((slab_flags_t __force)0x02000000UL) +# define SLAB_FAILSLAB ((slab_flags_t __force)0x02000000U) #else -# define SLAB_FAILSLAB ((slab_flags_t __force)0x00000000UL) +# define SLAB_FAILSLAB 0 #endif /* Account to memcg */ #if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB) -# define SLAB_ACCOUNT ((slab_flags_t __force)0x04000000UL) +# define SLAB_ACCOUNT ((slab_flags_t __force)0x04000000U) #else -# define SLAB_ACCOUNT ((slab_flags_t __force)0x00000000UL) +# define SLAB_ACCOUNT 0 #endif #ifdef CONFIG_KASAN -#define SLAB_KASAN ((slab_flags_t __force)0x08000000UL) +#define SLAB_KASAN ((slab_flags_t __force)0x08000000U) #else -#define SLAB_KASAN ((slab_flags_t __force)0x00000000UL) +#define SLAB_KASAN 0 #endif /* The following flags affect the page allocator grouping pages by mobility */ /* Objects are reclaimable */ -#define SLAB_RECLAIM_ACCOUNT ((slab_flags_t __force)0x00020000UL) +#define SLAB_RECLAIM_ACCOUNT ((slab_flags_t __force)0x00020000U) #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */ /* * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests. diff -puN include/linux/types.h~slab-slub-slob-convert-slab_flags_t-to-32-bit include/linux/types.h --- a/include/linux/types.h~slab-slub-slob-convert-slab_flags_t-to-32-bit +++ a/include/linux/types.h @@ -156,7 +156,7 @@ typedef u32 dma_addr_t; #endif typedef unsigned __bitwise gfp_t; -typedef unsigned long __bitwise slab_flags_t; +typedef unsigned __bitwise slab_flags_t; typedef unsigned __bitwise fmode_t; #ifdef CONFIG_PHYS_ADDR_T_64BIT diff -puN mm/slab.c~slab-slub-slob-convert-slab_flags_t-to-32-bit mm/slab.c --- a/mm/slab.c~slab-slub-slob-convert-slab_flags_t-to-32-bit +++ a/mm/slab.c @@ -252,8 +252,8 @@ static void kmem_cache_node_init(struct MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \ } while (0) -#define CFLGS_OBJFREELIST_SLAB ((slab_flags_t __force)0x40000000UL) -#define CFLGS_OFF_SLAB ((slab_flags_t __force)0x80000000UL) +#define CFLGS_OBJFREELIST_SLAB ((slab_flags_t __force)0x40000000U) +#define CFLGS_OFF_SLAB ((slab_flags_t __force)0x80000000U) #define OBJFREELIST_SLAB(x) ((x)->flags & CFLGS_OBJFREELIST_SLAB) #define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB) diff -puN mm/slub.c~slab-slub-slob-convert-slab_flags_t-to-32-bit mm/slub.c --- a/mm/slub.c~slab-slub-slob-convert-slab_flags_t-to-32-bit +++ a/mm/slub.c @@ -194,9 +194,9 @@ static inline bool kmem_cache_has_cpu_pa /* Internal SLUB flags */ /* Poison object */ -#define __OBJECT_POISON ((slab_flags_t __force)0x80000000UL) +#define __OBJECT_POISON ((slab_flags_t __force)0x80000000U) /* Use cmpxchg_double */ -#define __CMPXCHG_DOUBLE ((slab_flags_t __force)0x40000000UL) +#define __CMPXCHG_DOUBLE ((slab_flags_t __force)0x40000000U) /* * Tracking user of a slab. @@ -3657,7 +3657,7 @@ error: if (flags & SLAB_PANIC) panic("Cannot create slab %s size=%lu realsize=%u order=%u offset=%u flags=%lx\n", s->name, (unsigned long)s->size, s->size, - oo_order(s->oo), s->offset, flags); + oo_order(s->oo), s->offset, (unsigned long)flags); return -EINVAL; } _ -- 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
