/*
- * linux/mm/slab.h
- * Written by Mark Hemment, 1996.
- * (markhe@nextd.demon.co.uk)
+ * Written by Mark Hemment, 1996 (markhe@nextd.demon.co.uk).
+ *
+ * (C) SGI 2006, Christoph Lameter
+ * Cleaned up and restructured to ease the addition of alternative
+ * implementations of SLAB allocators.
*/
#ifndef _LINUX_SLAB_H
#define _LINUX_SLAB_H
-#if defined(__KERNEL__)
-
-typedef struct kmem_cache kmem_cache_t;
+#include <linux/gfp.h>
+#include <linux/types.h>
-#include <linux/gfp.h>
-#include <linux/init.h>
-#include <linux/types.h>
-#include <asm/page.h> /* kmalloc_sizes.h needs PAGE_SIZE */
-#include <asm/cache.h> /* kmalloc_sizes.h needs L1_CACHE_BYTES */
+/*
+ * Flags to pass to kmem_cache_create().
+ * The ones marked DEBUG are only valid if CONFIG_SLAB_DEBUG is set.
+ */
+#define SLAB_DEBUG_FREE 0x00000100UL /* DEBUG: Perform (expensive) checks on free */
+#define SLAB_RED_ZONE 0x00000400UL /* DEBUG: Red zone objs in a cache */
+#define SLAB_POISON 0x00000800UL /* DEBUG: Poison objects */
+#define SLAB_HWCACHE_ALIGN 0x00002000UL /* Align objs on cache lines */
+#define SLAB_CACHE_DMA 0x00004000UL /* Use GFP_DMA memory */
+#define SLAB_STORE_USER 0x00010000UL /* DEBUG: Store the last owner for bug hunting */
+#define SLAB_PANIC 0x00040000UL /* Panic if kmem_cache_create() fails */
+/*
+ * SLAB_DESTROY_BY_RCU - **WARNING** READ THIS!
+ *
+ * This delays freeing the SLAB page by a grace period, it does _NOT_
+ * delay object freeing. This means that if you do kmem_cache_free()
+ * that memory location is free to be reused at any time. Thus it may
+ * be possible to see another object there in the same RCU grace period.
+ *
+ * This feature only ensures the memory location backing the object
+ * stays valid, the trick to using this is relying on an independent
+ * object validation pass. Something like:
+ *
+ * rcu_read_lock()
+ * again:
+ * obj = lockless_lookup(key);
+ * if (obj) {
+ * if (!try_get_ref(obj)) // might fail for free objects
+ * goto again;
+ *
+ * if (obj->key != key) { // not the object we expected
+ * put_ref(obj);
+ * goto again;
+ * }
+ * }
+ * rcu_read_unlock();
+ *
+ * See also the comment on struct slab_rcu in mm/slab.c.
+ */
+#define SLAB_DESTROY_BY_RCU 0x00080000UL /* Defer freeing slabs to RCU */
+#define SLAB_MEM_SPREAD 0x00100000UL /* Spread some memory over cpuset */
+#define SLAB_TRACE 0x00200000UL /* Trace allocations and frees */
-/* flags for kmem_cache_alloc() */
-#define SLAB_NOFS GFP_NOFS
-#define SLAB_NOIO GFP_NOIO
-#define SLAB_ATOMIC GFP_ATOMIC
-#define SLAB_USER GFP_USER
-#define SLAB_KERNEL GFP_KERNEL
-#define SLAB_DMA GFP_DMA
+/* Flag to prevent checks on free */
+#ifdef CONFIG_DEBUG_OBJECTS
+# define SLAB_DEBUG_OBJECTS 0x00400000UL
+#else
+# define SLAB_DEBUG_OBJECTS 0x00000000UL
+#endif
-#define SLAB_LEVEL_MASK GFP_LEVEL_MASK
+#define SLAB_NOLEAKTRACE 0x00800000UL /* Avoid kmemleak tracing */
-#define SLAB_NO_GROW __GFP_NO_GROW /* don't grow a cache */
+/* Don't track use of uninitialized memory */
+#ifdef CONFIG_KMEMCHECK
+# define SLAB_NOTRACK 0x01000000UL
+#else
+# define SLAB_NOTRACK 0x00000000UL
+#endif
-/* flags to pass to kmem_cache_create().
- * The first 3 are only valid when the allocator as been build
- * SLAB_DEBUG_SUPPORT.
+/* The following flags affect the page allocator grouping pages by mobility */
+#define SLAB_RECLAIM_ACCOUNT 0x00020000UL /* Objects are reclaimable */
+#define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */
+/*
+ * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.
+ *
+ * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault.
+ *
+ * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can.
+ * Both make kfree a no-op.
*/
-#define SLAB_DEBUG_FREE 0x00000100UL /* Peform (expensive) checks on free */
-#define SLAB_DEBUG_INITIAL 0x00000200UL /* Call constructor (as verifier) */
-#define SLAB_RED_ZONE 0x00000400UL /* Red zone objs in a cache */
-#define SLAB_POISON 0x00000800UL /* Poison objects */
-#define SLAB_HWCACHE_ALIGN 0x00002000UL /* align objs on a h/w cache lines */
-#define SLAB_CACHE_DMA 0x00004000UL /* use GFP_DMA memory */
-#define SLAB_MUST_HWCACHE_ALIGN 0x00008000UL /* force alignment */
-#define SLAB_STORE_USER 0x00010000UL /* store the last owner for bug hunting */
-#define SLAB_RECLAIM_ACCOUNT 0x00020000UL /* track pages allocated to indicate
- what is reclaimable later*/
-#define SLAB_PANIC 0x00040000UL /* panic if kmem_cache_create() fails */
-#define SLAB_DESTROY_BY_RCU 0x00080000UL /* defer freeing pages to RCU */
-#define SLAB_MEM_SPREAD 0x00100000UL /* Spread some memory over cpuset */
+#define ZERO_SIZE_PTR ((void *)16)
-/* flags passed to a constructor func */
-#define SLAB_CTOR_CONSTRUCTOR 0x001UL /* if not set, then deconstructor */
-#define SLAB_CTOR_ATOMIC 0x002UL /* tell constructor it can't sleep */
-#define SLAB_CTOR_VERIFY 0x004UL /* tell constructor it's a verify call */
+#define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \
+ (unsigned long)ZERO_SIZE_PTR)
-#ifndef CONFIG_SLOB
+/*
+ * struct kmem_cache related prototypes
+ */
+void __init kmem_cache_init(void);
+int slab_is_available(void);
+
+struct kmem_cache *kmem_cache_create(const char *, size_t, size_t,
+ unsigned long,
+ void (*)(void *));
+void kmem_cache_destroy(struct kmem_cache *);
+int kmem_cache_shrink(struct kmem_cache *);
+void kmem_cache_free(struct kmem_cache *, void *);
+unsigned int kmem_cache_size(struct kmem_cache *);
+const char *kmem_cache_name(struct kmem_cache *);
+int kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr);
-/* prototypes */
-extern void __init kmem_cache_init(void);
+/*
+ * Please use this macro to create slab caches. Simply specify the
+ * name of the structure and maybe some flags that are listed above.
+ *
+ * The alignment of the struct determines object alignment. If you
+ * f.e. add ____cacheline_aligned_in_smp to the struct declaration
+ * then the objects will be properly aligned in SMP configurations.
+ */
+#define KMEM_CACHE(__struct, __flags) kmem_cache_create(#__struct,\
+ sizeof(struct __struct), __alignof__(struct __struct),\
+ (__flags), NULL)
-extern kmem_cache_t *kmem_cache_create(const char *, size_t, size_t, unsigned long,
- void (*)(void *, kmem_cache_t *, unsigned long),
- void (*)(void *, kmem_cache_t *, unsigned long));
-extern int kmem_cache_destroy(kmem_cache_t *);
-extern int kmem_cache_shrink(kmem_cache_t *);
-extern void *kmem_cache_alloc(kmem_cache_t *, gfp_t);
-extern void *kmem_cache_zalloc(struct kmem_cache *, gfp_t);
-extern void kmem_cache_free(kmem_cache_t *, void *);
-extern unsigned int kmem_cache_size(kmem_cache_t *);
-extern const char *kmem_cache_name(kmem_cache_t *);
+/*
+ * The largest kmalloc size supported by the slab allocators is
+ * 32 megabyte (2^25) or the maximum allocatable page order if that is
+ * less than 32 MB.
+ *
+ * WARNING: Its not easy to increase this value since the allocators have
+ * to do various tricks to work around compiler limitations in order to
+ * ensure proper constant folding.
+ */
+#define KMALLOC_SHIFT_HIGH ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \
+ (MAX_ORDER + PAGE_SHIFT - 1) : 25)
+
+#define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_HIGH)
+#define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_HIGH - PAGE_SHIFT)
-/* Size description struct for general caches. */
-struct cache_sizes {
- size_t cs_size;
- kmem_cache_t *cs_cachep;
- kmem_cache_t *cs_dmacachep;
-};
-extern struct cache_sizes malloc_sizes[];
+/*
+ * Common kmalloc functions provided by all allocators
+ */
+void * __must_check __krealloc(const void *, size_t, gfp_t);
+void * __must_check krealloc(const void *, size_t, gfp_t);
+void kfree(const void *);
+void kzfree(const void *);
+size_t ksize(const void *);
-extern void *__kmalloc(size_t, gfp_t);
-#ifndef CONFIG_DEBUG_SLAB
-#define ____kmalloc(size, flags) __kmalloc(size, flags)
+/*
+ * Allocator specific definitions. These are mainly used to establish optimized
+ * ways to convert kmalloc() calls to kmem_cache_alloc() invocations by
+ * selecting the appropriate general cache at compile time.
+ *
+ * Allocators must define at least:
+ *
+ * kmem_cache_alloc()
+ * __kmalloc()
+ * kmalloc()
+ *
+ * Those wishing to support NUMA must also define:
+ *
+ * kmem_cache_alloc_node()
+ * kmalloc_node()
+ *
+ * See each allocator definition file for additional comments and
+ * implementation notes.
+ */
+#ifdef CONFIG_SLUB
+#include <linux/slub_def.h>
+#elif defined(CONFIG_SLOB)
+#include <linux/slob_def.h>
#else
-extern void *__kmalloc_track_caller(size_t, gfp_t, void*);
-#define ____kmalloc(size, flags) \
- __kmalloc_track_caller(size, flags, __builtin_return_address(0))
+#include <linux/slab_def.h>
#endif
/**
- * kmalloc - allocate memory
- * @size: how many bytes of memory are required.
+ * kcalloc - allocate memory for an array. The memory is set to zero.
+ * @n: number of elements.
+ * @size: element size.
* @flags: the type of memory to allocate.
*
- * kmalloc is the normal method of allocating memory
- * in the kernel.
- *
* The @flags argument may be one of:
*
* %GFP_USER - Allocate memory on behalf of user. May sleep.
*
* %GFP_KERNEL - Allocate normal kernel ram. May sleep.
*
- * %GFP_ATOMIC - Allocation will not sleep.
+ * %GFP_ATOMIC - Allocation will not sleep. May use emergency pools.
* For example, use this inside interrupt handlers.
*
* %GFP_HIGHUSER - Allocate pages from high memory.
*
* %GFP_NOFS - Do not make any fs calls while trying to get memory.
*
+ * %GFP_NOWAIT - Allocation will not sleep.
+ *
+ * %GFP_THISNODE - Allocate node-local memory only.
+ *
+ * %GFP_DMA - Allocation suitable for DMA.
+ * Should only be used for kmalloc() caches. Otherwise, use a
+ * slab created with SLAB_DMA.
+ *
* Also it is possible to set different flags by OR'ing
* in one or more of the following additional @flags:
*
* %__GFP_COLD - Request cache-cold pages instead of
* trying to return cache-warm pages.
*
- * %__GFP_DMA - Request memory from the DMA-capable zone.
- *
* %__GFP_HIGH - This allocation has high priority and may use emergency pools.
*
- * %__GFP_HIGHMEM - Allocated memory may be from highmem.
- *
* %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail
* (think twice before using).
*
* %__GFP_NOWARN - If allocation fails, don't issue any warnings.
*
* %__GFP_REPEAT - If allocation fails initially, try once more before failing.
+ *
+ * There are other flags available as well, but these are not intended
+ * for general use, and so are not documented here. For a full list of
+ * potential flags, always refer to linux/gfp.h.
*/
-static inline void *kmalloc(size_t size, gfp_t flags)
+static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
{
- if (__builtin_constant_p(size)) {
- int i = 0;
-#define CACHE(x) \
- if (size <= x) \
- goto found; \
- else \
- i++;
-#include "kmalloc_sizes.h"
-#undef CACHE
- {
- extern void __you_cannot_kmalloc_that_much(void);
- __you_cannot_kmalloc_that_much();
- }
-found:
- return kmem_cache_alloc((flags & GFP_DMA) ?
- malloc_sizes[i].cs_dmacachep :
- malloc_sizes[i].cs_cachep, flags);
- }
- return __kmalloc(size, flags);
+ if (size != 0 && n > ULONG_MAX / size)
+ return NULL;
+ return __kmalloc(n * size, flags | __GFP_ZERO);
}
-extern void *__kzalloc(size_t, gfp_t);
-
+#if !defined(CONFIG_NUMA) && !defined(CONFIG_SLOB)
/**
- * kzalloc - allocate memory. The memory is set to zero.
+ * kmalloc_node - allocate memory from a specific node
* @size: how many bytes of memory are required.
- * @flags: the type of memory to allocate (see kmalloc).
+ * @flags: the type of memory to allocate (see kcalloc).
+ * @node: node to allocate from.
+ *
+ * kmalloc() for non-local nodes, used to allocate from a specific node
+ * if available. Equivalent to kmalloc() in the non-NUMA single-node
+ * case.
*/
-static inline void *kzalloc(size_t size, gfp_t flags)
+static inline void *kmalloc_node(size_t size, gfp_t flags, int node)
{
- if (__builtin_constant_p(size)) {
- int i = 0;
-#define CACHE(x) \
- if (size <= x) \
- goto found; \
- else \
- i++;
-#include "kmalloc_sizes.h"
-#undef CACHE
- {
- extern void __you_cannot_kzalloc_that_much(void);
- __you_cannot_kzalloc_that_much();
- }
-found:
- return kmem_cache_zalloc((flags & GFP_DMA) ?
- malloc_sizes[i].cs_dmacachep :
- malloc_sizes[i].cs_cachep, flags);
- }
- return __kzalloc(size, flags);
+ return kmalloc(size, flags);
}
-/**
- * kcalloc - allocate memory for an array. The memory is set to zero.
- * @n: number of elements.
- * @size: element size.
- * @flags: the type of memory to allocate.
- */
-static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
+static inline void *__kmalloc_node(size_t size, gfp_t flags, int node)
{
- if (n != 0 && size > ULONG_MAX / n)
- return NULL;
- return kzalloc(n * size, flags);
+ return __kmalloc(size, flags);
}
-extern void kfree(const void *);
-extern unsigned int ksize(const void *);
-extern int slab_is_available(void);
+void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
-#ifdef CONFIG_NUMA
-extern void *kmem_cache_alloc_node(kmem_cache_t *, gfp_t flags, int node);
-extern void *__kmalloc_node(size_t size, gfp_t flags, int node);
-
-static inline void *kmalloc_node(size_t size, gfp_t flags, int node)
-{
- if (__builtin_constant_p(size)) {
- int i = 0;
-#define CACHE(x) \
- if (size <= x) \
- goto found; \
- else \
- i++;
-#include "kmalloc_sizes.h"
-#undef CACHE
- {
- extern void __you_cannot_kmalloc_that_much(void);
- __you_cannot_kmalloc_that_much();
- }
-found:
- return kmem_cache_alloc_node((flags & GFP_DMA) ?
- malloc_sizes[i].cs_dmacachep :
- malloc_sizes[i].cs_cachep, flags, node);
- }
- return __kmalloc_node(size, flags, node);
-}
-#else
-static inline void *kmem_cache_alloc_node(kmem_cache_t *cachep, gfp_t flags, int node)
+static inline void *kmem_cache_alloc_node(struct kmem_cache *cachep,
+ gfp_t flags, int node)
{
return kmem_cache_alloc(cachep, flags);
}
-static inline void *kmalloc_node(size_t size, gfp_t flags, int node)
-{
- return kmalloc(size, flags);
-}
-#endif
+#endif /* !CONFIG_NUMA && !CONFIG_SLOB */
+
+/*
+ * kmalloc_track_caller is a special version of kmalloc that records the
+ * calling function of the routine calling it for slab leak tracking instead
+ * of just the calling function (confusing, eh?).
+ * It's useful when the call to kmalloc comes from a widely-used standard
+ * allocator where we care about the real place the memory allocation
+ * request comes from.
+ */
+#if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB)
+extern void *__kmalloc_track_caller(size_t, gfp_t, unsigned long);
+#define kmalloc_track_caller(size, flags) \
+ __kmalloc_track_caller(size, flags, _RET_IP_)
+#else
+#define kmalloc_track_caller(size, flags) \
+ __kmalloc(size, flags)
+#endif /* DEBUG_SLAB */
-extern int FASTCALL(kmem_cache_reap(int));
-extern int FASTCALL(kmem_ptr_validate(kmem_cache_t *cachep, void *ptr));
+#ifdef CONFIG_NUMA
+/*
+ * kmalloc_node_track_caller is a special version of kmalloc_node that
+ * records the calling function of the routine calling it for slab leak
+ * tracking instead of just the calling function (confusing, eh?).
+ * It's useful when the call to kmalloc_node comes from a widely-used
+ * standard allocator where we care about the real place the memory
+ * allocation request comes from.
+ */
+#if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB)
+extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, unsigned long);
+#define kmalloc_node_track_caller(size, flags, node) \
+ __kmalloc_node_track_caller(size, flags, node, \
+ _RET_IP_)
+#else
+#define kmalloc_node_track_caller(size, flags, node) \
+ __kmalloc_node(size, flags, node)
+#endif
-#else /* CONFIG_SLOB */
+#else /* CONFIG_NUMA */
-/* SLOB allocator routines */
+#define kmalloc_node_track_caller(size, flags, node) \
+ kmalloc_track_caller(size, flags)
-void kmem_cache_init(void);
-struct kmem_cache *kmem_cache_create(const char *c, size_t, size_t,
- unsigned long,
- void (*)(void *, struct kmem_cache *, unsigned long),
- void (*)(void *, struct kmem_cache *, unsigned long));
-int kmem_cache_destroy(struct kmem_cache *c);
-void *kmem_cache_alloc(struct kmem_cache *c, gfp_t flags);
-void *kmem_cache_zalloc(struct kmem_cache *, gfp_t);
-void kmem_cache_free(struct kmem_cache *c, void *b);
-const char *kmem_cache_name(struct kmem_cache *);
-void *kmalloc(size_t size, gfp_t flags);
-void *__kzalloc(size_t size, gfp_t flags);
-void kfree(const void *m);
-unsigned int ksize(const void *m);
-unsigned int kmem_cache_size(struct kmem_cache *c);
+#endif /* CONFIG_NUMA */
-static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
+/*
+ * Shortcuts
+ */
+static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags)
{
- return __kzalloc(n * size, flags);
+ return kmem_cache_alloc(k, flags | __GFP_ZERO);
}
-#define kmem_cache_shrink(d) (0)
-#define kmem_cache_reap(a)
-#define kmem_ptr_validate(a, b) (0)
-#define kmem_cache_alloc_node(c, f, n) kmem_cache_alloc(c, f)
-#define kmalloc_node(s, f, n) kmalloc(s, f)
-#define kzalloc(s, f) __kzalloc(s, f)
-#define ____kmalloc kmalloc
-
-#endif /* CONFIG_SLOB */
-
-/* System wide caches */
-extern kmem_cache_t *vm_area_cachep;
-extern kmem_cache_t *names_cachep;
-extern kmem_cache_t *files_cachep;
-extern kmem_cache_t *filp_cachep;
-extern kmem_cache_t *fs_cachep;
-extern kmem_cache_t *sighand_cachep;
-extern kmem_cache_t *bio_cachep;
+/**
+ * kzalloc - allocate memory. The memory is set to zero.
+ * @size: how many bytes of memory are required.
+ * @flags: the type of memory to allocate (see kmalloc).
+ */
+static inline void *kzalloc(size_t size, gfp_t flags)
+{
+ return kmalloc(size, flags | __GFP_ZERO);
+}
-extern atomic_t slab_reclaim_pages;
+/**
+ * kzalloc_node - allocate zeroed memory from a particular memory node.
+ * @size: how many bytes of memory are required.
+ * @flags: the type of memory to allocate (see kmalloc).
+ * @node: memory node from which to allocate
+ */
+static inline void *kzalloc_node(size_t size, gfp_t flags, int node)
+{
+ return kmalloc_node(size, flags | __GFP_ZERO, node);
+}
-#endif /* __KERNEL__ */
+void __init kmem_cache_init_late(void);
#endif /* _LINUX_SLAB_H */
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