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@linux-foundation.org: fix printk warning]
Link: http://lkml.kernel.org/r/20171021100635.GA8287@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/slab.h b/include/linux/slab.h
index 0c4c579..f37cb93 100644 (file)
--- a/include/linux/slab.h
+++ b/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 --git a/include/linux/types.h b/include/linux/types.h
index 732b52c..c94d59e 100644 (file)
--- a/include/linux/types.h
+++ b/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 --git a/mm/slab.c b/mm/slab.c
index 19b1b9f..7a5e088 100644 (file)
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -252,8 +252,8 @@ static void kmem_cache_node_init(struct kmem_cache_node *parent)
        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 --git a/mm/slub.c b/mm/slub.c
index 482d1da..33957fd 100644 (file)
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -194,9 +194,9 @@ static inline bool kmem_cache_has_cpu_partial(struct kmem_cache *s)
 
 /* 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;
 }