Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/mm/slab.c b/mm/slab.c
new file mode 100644
index 0000000..ec660d8
--- /dev/null
+++ b/mm/slab.c
@@ -0,0 +1,3060 @@
+/*
+ * linux/mm/slab.c
+ * Written by Mark Hemment, 1996/97.
+ * (markhe@nextd.demon.co.uk)
+ *
+ * kmem_cache_destroy() + some cleanup - 1999 Andrea Arcangeli
+ *
+ * Major cleanup, different bufctl logic, per-cpu arrays
+ * (c) 2000 Manfred Spraul
+ *
+ * Cleanup, make the head arrays unconditional, preparation for NUMA
+ * (c) 2002 Manfred Spraul
+ *
+ * An implementation of the Slab Allocator as described in outline in;
+ * UNIX Internals: The New Frontiers by Uresh Vahalia
+ * Pub: Prentice Hall ISBN 0-13-101908-2
+ * or with a little more detail in;
+ * The Slab Allocator: An Object-Caching Kernel Memory Allocator
+ * Jeff Bonwick (Sun Microsystems).
+ * Presented at: USENIX Summer 1994 Technical Conference
+ *
+ * The memory is organized in caches, one cache for each object type.
+ * (e.g. inode_cache, dentry_cache, buffer_head, vm_area_struct)
+ * Each cache consists out of many slabs (they are small (usually one
+ * page long) and always contiguous), and each slab contains multiple
+ * initialized objects.
+ *
+ * This means, that your constructor is used only for newly allocated
+ * slabs and you must pass objects with the same intializations to
+ * kmem_cache_free.
+ *
+ * Each cache can only support one memory type (GFP_DMA, GFP_HIGHMEM,
+ * normal). If you need a special memory type, then must create a new
+ * cache for that memory type.
+ *
+ * In order to reduce fragmentation, the slabs are sorted in 3 groups:
+ * full slabs with 0 free objects
+ * partial slabs
+ * empty slabs with no allocated objects
+ *
+ * If partial slabs exist, then new allocations come from these slabs,
+ * otherwise from empty slabs or new slabs are allocated.
+ *
+ * kmem_cache_destroy() CAN CRASH if you try to allocate from the cache
+ * during kmem_cache_destroy(). The caller must prevent concurrent allocs.
+ *
+ * Each cache has a short per-cpu head array, most allocs
+ * and frees go into that array, and if that array overflows, then 1/2
+ * of the entries in the array are given back into the global cache.
+ * The head array is strictly LIFO and should improve the cache hit rates.
+ * On SMP, it additionally reduces the spinlock operations.
+ *
+ * The c_cpuarray may not be read with enabled local interrupts -
+ * it's changed with a smp_call_function().
+ *
+ * SMP synchronization:
+ * constructors and destructors are called without any locking.
+ * Several members in kmem_cache_t and struct slab never change, they
+ * are accessed without any locking.
+ * The per-cpu arrays are never accessed from the wrong cpu, no locking,
+ * and local interrupts are disabled so slab code is preempt-safe.
+ * The non-constant members are protected with a per-cache irq spinlock.
+ *
+ * Many thanks to Mark Hemment, who wrote another per-cpu slab patch
+ * in 2000 - many ideas in the current implementation are derived from
+ * his patch.
+ *
+ * Further notes from the original documentation:
+ *
+ * 11 April '97. Started multi-threading - markhe
+ * The global cache-chain is protected by the semaphore 'cache_chain_sem'.
+ * The sem is only needed when accessing/extending the cache-chain, which
+ * can never happen inside an interrupt (kmem_cache_create(),
+ * kmem_cache_shrink() and kmem_cache_reap()).
+ *
+ * At present, each engine can be growing a cache. This should be blocked.
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/cache.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/compiler.h>
+#include <linux/seq_file.h>
+#include <linux/notifier.h>
+#include <linux/kallsyms.h>
+#include <linux/cpu.h>
+#include <linux/sysctl.h>
+#include <linux/module.h>
+#include <linux/rcupdate.h>
+
+#include <asm/uaccess.h>
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
+#include <asm/page.h>
+
+/*
+ * DEBUG - 1 for kmem_cache_create() to honour; SLAB_DEBUG_INITIAL,
+ * SLAB_RED_ZONE & SLAB_POISON.
+ * 0 for faster, smaller code (especially in the critical paths).
+ *
+ * STATS - 1 to collect stats for /proc/slabinfo.
+ * 0 for faster, smaller code (especially in the critical paths).
+ *
+ * FORCED_DEBUG - 1 enables SLAB_RED_ZONE and SLAB_POISON (if possible)
+ */
+
+#ifdef CONFIG_DEBUG_SLAB
+#define DEBUG 1
+#define STATS 1
+#define FORCED_DEBUG 1
+#else
+#define DEBUG 0
+#define STATS 0
+#define FORCED_DEBUG 0
+#endif
+
+
+/* Shouldn't this be in a header file somewhere? */
+#define BYTES_PER_WORD sizeof(void *)
+
+#ifndef cache_line_size
+#define cache_line_size() L1_CACHE_BYTES
+#endif
+
+#ifndef ARCH_KMALLOC_MINALIGN
+/*
+ * Enforce a minimum alignment for the kmalloc caches.
+ * Usually, the kmalloc caches are cache_line_size() aligned, except when
+ * DEBUG and FORCED_DEBUG are enabled, then they are BYTES_PER_WORD aligned.
+ * Some archs want to perform DMA into kmalloc caches and need a guaranteed
+ * alignment larger than BYTES_PER_WORD. ARCH_KMALLOC_MINALIGN allows that.
+ * Note that this flag disables some debug features.
+ */
+#define ARCH_KMALLOC_MINALIGN 0
+#endif
+
+#ifndef ARCH_SLAB_MINALIGN
+/*
+ * Enforce a minimum alignment for all caches.
+ * Intended for archs that get misalignment faults even for BYTES_PER_WORD
+ * aligned buffers. Includes ARCH_KMALLOC_MINALIGN.
+ * If possible: Do not enable this flag for CONFIG_DEBUG_SLAB, it disables
+ * some debug features.
+ */
+#define ARCH_SLAB_MINALIGN 0
+#endif
+
+#ifndef ARCH_KMALLOC_FLAGS
+#define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN
+#endif
+
+/* Legal flag mask for kmem_cache_create(). */
+#if DEBUG
+# define CREATE_MASK (SLAB_DEBUG_INITIAL | SLAB_RED_ZONE | \
+ SLAB_POISON | SLAB_HWCACHE_ALIGN | \
+ SLAB_NO_REAP | SLAB_CACHE_DMA | \
+ SLAB_MUST_HWCACHE_ALIGN | SLAB_STORE_USER | \
+ SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
+ SLAB_DESTROY_BY_RCU)
+#else
+# define CREATE_MASK (SLAB_HWCACHE_ALIGN | SLAB_NO_REAP | \
+ SLAB_CACHE_DMA | SLAB_MUST_HWCACHE_ALIGN | \
+ SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
+ SLAB_DESTROY_BY_RCU)
+#endif
+
+/*
+ * 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.
+ */
+
+#define BUFCTL_END (((kmem_bufctl_t)(~0U))-0)
+#define BUFCTL_FREE (((kmem_bufctl_t)(~0U))-1)
+#define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-2)
+
+/* Max number of objs-per-slab for caches which use off-slab slabs.
+ * Needed to avoid a possible looping condition in cache_grow().
+ */
+static unsigned long offslab_limit;
+
+/*
+ * struct slab
+ *
+ * Manages the objs in a slab. Placed either at the beginning of mem allocated
+ * for a slab, or allocated from an general cache.
+ * Slabs are chained into three list: fully used, partial, fully free slabs.
+ */
+struct slab {
+ struct list_head list;
+ unsigned long colouroff;
+ void *s_mem; /* including colour offset */
+ unsigned int inuse; /* num of objs active in slab */
+ kmem_bufctl_t free;
+};
+
+/*
+ * struct slab_rcu
+ *
+ * slab_destroy on a SLAB_DESTROY_BY_RCU cache uses this structure to
+ * arrange for kmem_freepages to be called via RCU. This is useful if
+ * we need to approach a kernel structure obliquely, from its address
+ * obtained without the usual locking. We can lock the structure to
+ * stabilize it and check it's still at the given address, only if we
+ * can be sure that the memory has not been meanwhile reused for some
+ * other kind of object (which our subsystem's lock might corrupt).
+ *
+ * rcu_read_lock before reading the address, then rcu_read_unlock after
+ * taking the spinlock within the structure expected at that address.
+ *
+ * We assume struct slab_rcu can overlay struct slab when destroying.
+ */
+struct slab_rcu {
+ struct rcu_head head;
+ kmem_cache_t *cachep;
+ void *addr;
+};
+
+/*
+ * struct array_cache
+ *
+ * Per cpu structures
+ * Purpose:
+ * - LIFO ordering, to hand out cache-warm objects from _alloc
+ * - reduce the number of linked list operations
+ * - reduce spinlock operations
+ *
+ * The limit is stored in the per-cpu structure to reduce the data cache
+ * footprint.
+ *
+ */
+struct array_cache {
+ unsigned int avail;
+ unsigned int limit;
+ unsigned int batchcount;
+ unsigned int touched;
+};
+
+/* bootstrap: The caches do not work without cpuarrays anymore,
+ * but the cpuarrays are allocated from the generic caches...
+ */
+#define BOOT_CPUCACHE_ENTRIES 1
+struct arraycache_init {
+ struct array_cache cache;
+ void * entries[BOOT_CPUCACHE_ENTRIES];
+};
+
+/*
+ * The slab lists of all objects.
+ * Hopefully reduce the internal fragmentation
+ * NUMA: The spinlock could be moved from the kmem_cache_t
+ * into this structure, too. Figure out what causes
+ * fewer cross-node spinlock operations.
+ */
+struct kmem_list3 {
+ struct list_head slabs_partial; /* partial list first, better asm code */
+ struct list_head slabs_full;
+ struct list_head slabs_free;
+ unsigned long free_objects;
+ int free_touched;
+ unsigned long next_reap;
+ struct array_cache *shared;
+};
+
+#define LIST3_INIT(parent) \
+ { \
+ .slabs_full = LIST_HEAD_INIT(parent.slabs_full), \
+ .slabs_partial = LIST_HEAD_INIT(parent.slabs_partial), \
+ .slabs_free = LIST_HEAD_INIT(parent.slabs_free) \
+ }
+#define list3_data(cachep) \
+ (&(cachep)->lists)
+
+/* NUMA: per-node */
+#define list3_data_ptr(cachep, ptr) \
+ list3_data(cachep)
+
+/*
+ * kmem_cache_t
+ *
+ * manages a cache.
+ */
+
+struct kmem_cache_s {
+/* 1) per-cpu data, touched during every alloc/free */
+ struct array_cache *array[NR_CPUS];
+ unsigned int batchcount;
+ unsigned int limit;
+/* 2) touched by every alloc & free from the backend */
+ struct kmem_list3 lists;
+ /* NUMA: kmem_3list_t *nodelists[MAX_NUMNODES] */
+ unsigned int objsize;
+ unsigned int flags; /* constant flags */
+ unsigned int num; /* # of objs per slab */
+ unsigned int free_limit; /* upper limit of objects in the lists */
+ spinlock_t spinlock;
+
+/* 3) cache_grow/shrink */
+ /* order of pgs per slab (2^n) */
+ unsigned int gfporder;
+
+ /* force GFP flags, e.g. GFP_DMA */
+ unsigned int gfpflags;
+
+ size_t colour; /* cache colouring range */
+ unsigned int colour_off; /* colour offset */
+ unsigned int colour_next; /* cache colouring */
+ kmem_cache_t *slabp_cache;
+ unsigned int slab_size;
+ unsigned int dflags; /* dynamic flags */
+
+ /* constructor func */
+ void (*ctor)(void *, kmem_cache_t *, unsigned long);
+
+ /* de-constructor func */
+ void (*dtor)(void *, kmem_cache_t *, unsigned long);
+
+/* 4) cache creation/removal */
+ const char *name;
+ struct list_head next;
+
+/* 5) statistics */
+#if STATS
+ unsigned long num_active;
+ unsigned long num_allocations;
+ unsigned long high_mark;
+ unsigned long grown;
+ unsigned long reaped;
+ unsigned long errors;
+ unsigned long max_freeable;
+ unsigned long node_allocs;
+ atomic_t allochit;
+ atomic_t allocmiss;
+ atomic_t freehit;
+ atomic_t freemiss;
+#endif
+#if DEBUG
+ int dbghead;
+ int reallen;
+#endif
+};
+
+#define CFLGS_OFF_SLAB (0x80000000UL)
+#define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB)
+
+#define BATCHREFILL_LIMIT 16
+/* Optimization question: fewer reaps means less
+ * probability for unnessary cpucache drain/refill cycles.
+ *
+ * OTHO the cpuarrays can contain lots of objects,
+ * which could lock up otherwise freeable slabs.
+ */
+#define REAPTIMEOUT_CPUC (2*HZ)
+#define REAPTIMEOUT_LIST3 (4*HZ)
+
+#if STATS
+#define STATS_INC_ACTIVE(x) ((x)->num_active++)
+#define STATS_DEC_ACTIVE(x) ((x)->num_active--)
+#define STATS_INC_ALLOCED(x) ((x)->num_allocations++)
+#define STATS_INC_GROWN(x) ((x)->grown++)
+#define STATS_INC_REAPED(x) ((x)->reaped++)
+#define STATS_SET_HIGH(x) do { if ((x)->num_active > (x)->high_mark) \
+ (x)->high_mark = (x)->num_active; \
+ } while (0)
+#define STATS_INC_ERR(x) ((x)->errors++)
+#define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++)
+#define STATS_SET_FREEABLE(x, i) \
+ do { if ((x)->max_freeable < i) \
+ (x)->max_freeable = i; \
+ } while (0)
+
+#define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit)
+#define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss)
+#define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit)
+#define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss)
+#else
+#define STATS_INC_ACTIVE(x) do { } while (0)
+#define STATS_DEC_ACTIVE(x) do { } while (0)
+#define STATS_INC_ALLOCED(x) do { } while (0)
+#define STATS_INC_GROWN(x) do { } while (0)
+#define STATS_INC_REAPED(x) do { } while (0)
+#define STATS_SET_HIGH(x) do { } while (0)
+#define STATS_INC_ERR(x) do { } while (0)
+#define STATS_INC_NODEALLOCS(x) do { } while (0)
+#define STATS_SET_FREEABLE(x, i) \
+ do { } while (0)
+
+#define STATS_INC_ALLOCHIT(x) do { } while (0)
+#define STATS_INC_ALLOCMISS(x) do { } while (0)
+#define STATS_INC_FREEHIT(x) do { } while (0)
+#define STATS_INC_FREEMISS(x) do { } while (0)
+#endif
+
+#if DEBUG
+/* Magic nums for obj red zoning.
+ * Placed in the first word before and the first word after an obj.
+ */
+#define RED_INACTIVE 0x5A2CF071UL /* when obj is inactive */
+#define RED_ACTIVE 0x170FC2A5UL /* when obj is active */
+
+/* ...and for poisoning */
+#define POISON_INUSE 0x5a /* for use-uninitialised poisoning */
+#define POISON_FREE 0x6b /* for use-after-free poisoning */
+#define POISON_END 0xa5 /* end-byte of poisoning */
+
+/* memory layout of objects:
+ * 0 : objp
+ * 0 .. cachep->dbghead - BYTES_PER_WORD - 1: padding. This ensures that
+ * the end of an object is aligned with the end of the real
+ * allocation. Catches writes behind the end of the allocation.
+ * cachep->dbghead - BYTES_PER_WORD .. cachep->dbghead - 1:
+ * redzone word.
+ * cachep->dbghead: The real object.
+ * cachep->objsize - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long]
+ * cachep->objsize - 1* BYTES_PER_WORD: last caller address [BYTES_PER_WORD long]
+ */
+static int obj_dbghead(kmem_cache_t *cachep)
+{
+ return cachep->dbghead;
+}
+
+static int obj_reallen(kmem_cache_t *cachep)
+{
+ return cachep->reallen;
+}
+
+static unsigned long *dbg_redzone1(kmem_cache_t *cachep, void *objp)
+{
+ BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
+ return (unsigned long*) (objp+obj_dbghead(cachep)-BYTES_PER_WORD);
+}
+
+static unsigned long *dbg_redzone2(kmem_cache_t *cachep, void *objp)
+{
+ BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
+ if (cachep->flags & SLAB_STORE_USER)
+ return (unsigned long*) (objp+cachep->objsize-2*BYTES_PER_WORD);
+ return (unsigned long*) (objp+cachep->objsize-BYTES_PER_WORD);
+}
+
+static void **dbg_userword(kmem_cache_t *cachep, void *objp)
+{
+ BUG_ON(!(cachep->flags & SLAB_STORE_USER));
+ return (void**)(objp+cachep->objsize-BYTES_PER_WORD);
+}
+
+#else
+
+#define obj_dbghead(x) 0
+#define obj_reallen(cachep) (cachep->objsize)
+#define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long *)NULL;})
+#define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long *)NULL;})
+#define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;})
+
+#endif
+
+/*
+ * Maximum size of an obj (in 2^order pages)
+ * and absolute limit for the gfp order.
+ */
+#if defined(CONFIG_LARGE_ALLOCS)
+#define MAX_OBJ_ORDER 13 /* up to 32Mb */
+#define MAX_GFP_ORDER 13 /* up to 32Mb */
+#elif defined(CONFIG_MMU)
+#define MAX_OBJ_ORDER 5 /* 32 pages */
+#define MAX_GFP_ORDER 5 /* 32 pages */
+#else
+#define MAX_OBJ_ORDER 8 /* up to 1Mb */
+#define MAX_GFP_ORDER 8 /* up to 1Mb */
+#endif
+
+/*
+ * Do not go above this order unless 0 objects fit into the slab.
+ */
+#define BREAK_GFP_ORDER_HI 1
+#define BREAK_GFP_ORDER_LO 0
+static int slab_break_gfp_order = BREAK_GFP_ORDER_LO;
+
+/* Macros for storing/retrieving the cachep and or slab from the
+ * global 'mem_map'. These are used to find the slab an obj belongs to.
+ * With kfree(), these are used to find the cache which an obj belongs to.
+ */
+#define SET_PAGE_CACHE(pg,x) ((pg)->lru.next = (struct list_head *)(x))
+#define GET_PAGE_CACHE(pg) ((kmem_cache_t *)(pg)->lru.next)
+#define SET_PAGE_SLAB(pg,x) ((pg)->lru.prev = (struct list_head *)(x))
+#define GET_PAGE_SLAB(pg) ((struct slab *)(pg)->lru.prev)
+
+/* These are the default caches for kmalloc. Custom caches can have other sizes. */
+struct cache_sizes malloc_sizes[] = {
+#define CACHE(x) { .cs_size = (x) },
+#include <linux/kmalloc_sizes.h>
+ CACHE(ULONG_MAX)
+#undef CACHE
+};
+EXPORT_SYMBOL(malloc_sizes);
+
+/* Must match cache_sizes above. Out of line to keep cache footprint low. */
+struct cache_names {
+ char *name;
+ char *name_dma;
+};
+
+static struct cache_names __initdata cache_names[] = {
+#define CACHE(x) { .name = "size-" #x, .name_dma = "size-" #x "(DMA)" },
+#include <linux/kmalloc_sizes.h>
+ { NULL, }
+#undef CACHE
+};
+
+static struct arraycache_init initarray_cache __initdata =
+ { { 0, BOOT_CPUCACHE_ENTRIES, 1, 0} };
+static struct arraycache_init initarray_generic =
+ { { 0, BOOT_CPUCACHE_ENTRIES, 1, 0} };
+
+/* internal cache of cache description objs */
+static kmem_cache_t cache_cache = {
+ .lists = LIST3_INIT(cache_cache.lists),
+ .batchcount = 1,
+ .limit = BOOT_CPUCACHE_ENTRIES,
+ .objsize = sizeof(kmem_cache_t),
+ .flags = SLAB_NO_REAP,
+ .spinlock = SPIN_LOCK_UNLOCKED,
+ .name = "kmem_cache",
+#if DEBUG
+ .reallen = sizeof(kmem_cache_t),
+#endif
+};
+
+/* Guard access to the cache-chain. */
+static struct semaphore cache_chain_sem;
+static struct list_head cache_chain;
+
+/*
+ * vm_enough_memory() looks at this to determine how many
+ * slab-allocated pages are possibly freeable under pressure
+ *
+ * SLAB_RECLAIM_ACCOUNT turns this on per-slab
+ */
+atomic_t slab_reclaim_pages;
+EXPORT_SYMBOL(slab_reclaim_pages);
+
+/*
+ * chicken and egg problem: delay the per-cpu array allocation
+ * until the general caches are up.
+ */
+static enum {
+ NONE,
+ PARTIAL,
+ FULL
+} g_cpucache_up;
+
+static DEFINE_PER_CPU(struct work_struct, reap_work);
+
+static void free_block(kmem_cache_t* cachep, void** objpp, int len);
+static void enable_cpucache (kmem_cache_t *cachep);
+static void cache_reap (void *unused);
+
+static inline void **ac_entry(struct array_cache *ac)
+{
+ return (void**)(ac+1);
+}
+
+static inline struct array_cache *ac_data(kmem_cache_t *cachep)
+{
+ return cachep->array[smp_processor_id()];
+}
+
+static inline kmem_cache_t *kmem_find_general_cachep(size_t size, int gfpflags)
+{
+ struct cache_sizes *csizep = malloc_sizes;
+
+#if DEBUG
+ /* This happens if someone tries to call
+ * kmem_cache_create(), or __kmalloc(), before
+ * the generic caches are initialized.
+ */
+ BUG_ON(csizep->cs_cachep == NULL);
+#endif
+ while (size > csizep->cs_size)
+ csizep++;
+
+ /*
+ * Really subtile: The last entry with cs->cs_size==ULONG_MAX
+ * has cs_{dma,}cachep==NULL. Thus no special case
+ * for large kmalloc calls required.
+ */
+ if (unlikely(gfpflags & GFP_DMA))
+ return csizep->cs_dmacachep;
+ return csizep->cs_cachep;
+}
+
+/* Cal the num objs, wastage, and bytes left over for a given slab size. */
+static void cache_estimate(unsigned long gfporder, size_t size, size_t align,
+ int flags, size_t *left_over, unsigned int *num)
+{
+ int i;
+ size_t wastage = PAGE_SIZE<<gfporder;
+ size_t extra = 0;
+ size_t base = 0;
+
+ if (!(flags & CFLGS_OFF_SLAB)) {
+ base = sizeof(struct slab);
+ extra = sizeof(kmem_bufctl_t);
+ }
+ i = 0;
+ while (i*size + ALIGN(base+i*extra, align) <= wastage)
+ i++;
+ if (i > 0)
+ i--;
+
+ if (i > SLAB_LIMIT)
+ i = SLAB_LIMIT;
+
+ *num = i;
+ wastage -= i*size;
+ wastage -= ALIGN(base+i*extra, align);
+ *left_over = wastage;
+}
+
+#define slab_error(cachep, msg) __slab_error(__FUNCTION__, cachep, msg)
+
+static void __slab_error(const char *function, kmem_cache_t *cachep, char *msg)
+{
+ printk(KERN_ERR "slab error in %s(): cache `%s': %s\n",
+ function, cachep->name, msg);
+ dump_stack();
+}
+
+/*
+ * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz
+ * via the workqueue/eventd.
+ * Add the CPU number into the expiration time to minimize the possibility of
+ * the CPUs getting into lockstep and contending for the global cache chain
+ * lock.
+ */
+static void __devinit start_cpu_timer(int cpu)
+{
+ struct work_struct *reap_work = &per_cpu(reap_work, cpu);
+
+ /*
+ * When this gets called from do_initcalls via cpucache_init(),
+ * init_workqueues() has already run, so keventd will be setup
+ * at that time.
+ */
+ if (keventd_up() && reap_work->func == NULL) {
+ INIT_WORK(reap_work, cache_reap, NULL);
+ schedule_delayed_work_on(cpu, reap_work, HZ + 3 * cpu);
+ }
+}
+
+static struct array_cache *alloc_arraycache(int cpu, int entries,
+ int batchcount)
+{
+ int memsize = sizeof(void*)*entries+sizeof(struct array_cache);
+ struct array_cache *nc = NULL;
+
+ if (cpu != -1) {
+ kmem_cache_t *cachep;
+ cachep = kmem_find_general_cachep(memsize, GFP_KERNEL);
+ if (cachep)
+ nc = kmem_cache_alloc_node(cachep, cpu_to_node(cpu));
+ }
+ if (!nc)
+ nc = kmalloc(memsize, GFP_KERNEL);
+ if (nc) {
+ nc->avail = 0;
+ nc->limit = entries;
+ nc->batchcount = batchcount;
+ nc->touched = 0;
+ }
+ return nc;
+}
+
+static int __devinit cpuup_callback(struct notifier_block *nfb,
+ unsigned long action, void *hcpu)
+{
+ long cpu = (long)hcpu;
+ kmem_cache_t* cachep;
+
+ switch (action) {
+ case CPU_UP_PREPARE:
+ down(&cache_chain_sem);
+ list_for_each_entry(cachep, &cache_chain, next) {
+ struct array_cache *nc;
+
+ nc = alloc_arraycache(cpu, cachep->limit, cachep->batchcount);
+ if (!nc)
+ goto bad;
+
+ spin_lock_irq(&cachep->spinlock);
+ cachep->array[cpu] = nc;
+ cachep->free_limit = (1+num_online_cpus())*cachep->batchcount
+ + cachep->num;
+ spin_unlock_irq(&cachep->spinlock);
+
+ }
+ up(&cache_chain_sem);
+ break;
+ case CPU_ONLINE:
+ start_cpu_timer(cpu);
+ break;
+#ifdef CONFIG_HOTPLUG_CPU
+ case CPU_DEAD:
+ /* fall thru */
+ case CPU_UP_CANCELED:
+ down(&cache_chain_sem);
+
+ list_for_each_entry(cachep, &cache_chain, next) {
+ struct array_cache *nc;
+
+ spin_lock_irq(&cachep->spinlock);
+ /* cpu is dead; no one can alloc from it. */
+ nc = cachep->array[cpu];
+ cachep->array[cpu] = NULL;
+ cachep->free_limit -= cachep->batchcount;
+ free_block(cachep, ac_entry(nc), nc->avail);
+ spin_unlock_irq(&cachep->spinlock);
+ kfree(nc);
+ }
+ up(&cache_chain_sem);
+ break;
+#endif
+ }
+ return NOTIFY_OK;
+bad:
+ up(&cache_chain_sem);
+ return NOTIFY_BAD;
+}
+
+static struct notifier_block cpucache_notifier = { &cpuup_callback, NULL, 0 };
+
+/* Initialisation.
+ * Called after the gfp() functions have been enabled, and before smp_init().
+ */
+void __init kmem_cache_init(void)
+{
+ size_t left_over;
+ struct cache_sizes *sizes;
+ struct cache_names *names;
+
+ /*
+ * Fragmentation resistance on low memory - only use bigger
+ * page orders on machines with more than 32MB of memory.
+ */
+ if (num_physpages > (32 << 20) >> PAGE_SHIFT)
+ slab_break_gfp_order = BREAK_GFP_ORDER_HI;
+
+
+ /* Bootstrap is tricky, because several objects are allocated
+ * from caches that do not exist yet:
+ * 1) initialize the cache_cache cache: it contains the kmem_cache_t
+ * structures of all caches, except cache_cache itself: cache_cache
+ * is statically allocated.
+ * Initially an __init data area is used for the head array, it's
+ * replaced with a kmalloc allocated array at the end of the bootstrap.
+ * 2) Create the first kmalloc cache.
+ * The kmem_cache_t for the new cache is allocated normally. An __init
+ * data area is used for the head array.
+ * 3) Create the remaining kmalloc caches, with minimally sized head arrays.
+ * 4) Replace the __init data head arrays for cache_cache and the first
+ * kmalloc cache with kmalloc allocated arrays.
+ * 5) Resize the head arrays of the kmalloc caches to their final sizes.
+ */
+
+ /* 1) create the cache_cache */
+ init_MUTEX(&cache_chain_sem);
+ INIT_LIST_HEAD(&cache_chain);
+ list_add(&cache_cache.next, &cache_chain);
+ cache_cache.colour_off = cache_line_size();
+ cache_cache.array[smp_processor_id()] = &initarray_cache.cache;
+
+ cache_cache.objsize = ALIGN(cache_cache.objsize, cache_line_size());
+
+ cache_estimate(0, cache_cache.objsize, cache_line_size(), 0,
+ &left_over, &cache_cache.num);
+ if (!cache_cache.num)
+ BUG();
+
+ cache_cache.colour = left_over/cache_cache.colour_off;
+ cache_cache.colour_next = 0;
+ cache_cache.slab_size = ALIGN(cache_cache.num*sizeof(kmem_bufctl_t) +
+ sizeof(struct slab), cache_line_size());
+
+ /* 2+3) create the kmalloc caches */
+ sizes = malloc_sizes;
+ names = cache_names;
+
+ while (sizes->cs_size != ULONG_MAX) {
+ /* For performance, all the general caches are L1 aligned.
+ * This should be particularly beneficial on SMP boxes, as it
+ * eliminates "false sharing".
+ * Note for systems short on memory removing the alignment will
+ * allow tighter packing of the smaller caches. */
+ sizes->cs_cachep = kmem_cache_create(names->name,
+ sizes->cs_size, ARCH_KMALLOC_MINALIGN,
+ (ARCH_KMALLOC_FLAGS | SLAB_PANIC), NULL, NULL);
+
+ /* Inc off-slab bufctl limit until the ceiling is hit. */
+ if (!(OFF_SLAB(sizes->cs_cachep))) {
+ offslab_limit = sizes->cs_size-sizeof(struct slab);
+ offslab_limit /= sizeof(kmem_bufctl_t);
+ }
+
+ sizes->cs_dmacachep = kmem_cache_create(names->name_dma,
+ sizes->cs_size, ARCH_KMALLOC_MINALIGN,
+ (ARCH_KMALLOC_FLAGS | SLAB_CACHE_DMA | SLAB_PANIC),
+ NULL, NULL);
+
+ sizes++;
+ names++;
+ }
+ /* 4) Replace the bootstrap head arrays */
+ {
+ void * ptr;
+
+ ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
+ local_irq_disable();
+ BUG_ON(ac_data(&cache_cache) != &initarray_cache.cache);
+ memcpy(ptr, ac_data(&cache_cache), sizeof(struct arraycache_init));
+ cache_cache.array[smp_processor_id()] = ptr;
+ local_irq_enable();
+
+ ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
+ local_irq_disable();
+ BUG_ON(ac_data(malloc_sizes[0].cs_cachep) != &initarray_generic.cache);
+ memcpy(ptr, ac_data(malloc_sizes[0].cs_cachep),
+ sizeof(struct arraycache_init));
+ malloc_sizes[0].cs_cachep->array[smp_processor_id()] = ptr;
+ local_irq_enable();
+ }
+
+ /* 5) resize the head arrays to their final sizes */
+ {
+ kmem_cache_t *cachep;
+ down(&cache_chain_sem);
+ list_for_each_entry(cachep, &cache_chain, next)
+ enable_cpucache(cachep);
+ up(&cache_chain_sem);
+ }
+
+ /* Done! */
+ g_cpucache_up = FULL;
+
+ /* Register a cpu startup notifier callback
+ * that initializes ac_data for all new cpus
+ */
+ register_cpu_notifier(&cpucache_notifier);
+
+
+ /* The reap timers are started later, with a module init call:
+ * That part of the kernel is not yet operational.
+ */
+}
+
+static int __init cpucache_init(void)
+{
+ int cpu;
+
+ /*
+ * Register the timers that return unneeded
+ * pages to gfp.
+ */
+ for (cpu = 0; cpu < NR_CPUS; cpu++) {
+ if (cpu_online(cpu))
+ start_cpu_timer(cpu);
+ }
+
+ return 0;
+}
+
+__initcall(cpucache_init);
+
+/*
+ * Interface to system's page allocator. No need to hold the cache-lock.
+ *
+ * If we requested dmaable memory, we will get it. Even if we
+ * did not request dmaable memory, we might get it, but that
+ * would be relatively rare and ignorable.
+ */
+static void *kmem_getpages(kmem_cache_t *cachep, unsigned int __nocast flags, int nodeid)
+{
+ struct page *page;
+ void *addr;
+ int i;
+
+ flags |= cachep->gfpflags;
+ if (likely(nodeid == -1)) {
+ page = alloc_pages(flags, cachep->gfporder);
+ } else {
+ page = alloc_pages_node(nodeid, flags, cachep->gfporder);
+ }
+ if (!page)
+ return NULL;
+ addr = page_address(page);
+
+ i = (1 << cachep->gfporder);
+ if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
+ atomic_add(i, &slab_reclaim_pages);
+ add_page_state(nr_slab, i);
+ while (i--) {
+ SetPageSlab(page);
+ page++;
+ }
+ return addr;
+}
+
+/*
+ * Interface to system's page release.
+ */
+static void kmem_freepages(kmem_cache_t *cachep, void *addr)
+{
+ unsigned long i = (1<<cachep->gfporder);
+ struct page *page = virt_to_page(addr);
+ const unsigned long nr_freed = i;
+
+ while (i--) {
+ if (!TestClearPageSlab(page))
+ BUG();
+ page++;
+ }
+ sub_page_state(nr_slab, nr_freed);
+ if (current->reclaim_state)
+ current->reclaim_state->reclaimed_slab += nr_freed;
+ free_pages((unsigned long)addr, cachep->gfporder);
+ if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
+ atomic_sub(1<<cachep->gfporder, &slab_reclaim_pages);
+}
+
+static void kmem_rcu_free(struct rcu_head *head)
+{
+ struct slab_rcu *slab_rcu = (struct slab_rcu *) head;
+ kmem_cache_t *cachep = slab_rcu->cachep;
+
+ kmem_freepages(cachep, slab_rcu->addr);
+ if (OFF_SLAB(cachep))
+ kmem_cache_free(cachep->slabp_cache, slab_rcu);
+}
+
+#if DEBUG
+
+#ifdef CONFIG_DEBUG_PAGEALLOC
+static void store_stackinfo(kmem_cache_t *cachep, unsigned long *addr,
+ unsigned long caller)
+{
+ int size = obj_reallen(cachep);
+
+ addr = (unsigned long *)&((char*)addr)[obj_dbghead(cachep)];
+
+ if (size < 5*sizeof(unsigned long))
+ return;
+
+ *addr++=0x12345678;
+ *addr++=caller;
+ *addr++=smp_processor_id();
+ size -= 3*sizeof(unsigned long);
+ {
+ unsigned long *sptr = &caller;
+ unsigned long svalue;
+
+ while (!kstack_end(sptr)) {
+ svalue = *sptr++;
+ if (kernel_text_address(svalue)) {
+ *addr++=svalue;
+ size -= sizeof(unsigned long);
+ if (size <= sizeof(unsigned long))
+ break;
+ }
+ }
+
+ }
+ *addr++=0x87654321;
+}
+#endif
+
+static void poison_obj(kmem_cache_t *cachep, void *addr, unsigned char val)
+{
+ int size = obj_reallen(cachep);
+ addr = &((char*)addr)[obj_dbghead(cachep)];
+
+ memset(addr, val, size);
+ *(unsigned char *)(addr+size-1) = POISON_END;
+}
+
+static void dump_line(char *data, int offset, int limit)
+{
+ int i;
+ printk(KERN_ERR "%03x:", offset);
+ for (i=0;i<limit;i++) {
+ printk(" %02x", (unsigned char)data[offset+i]);
+ }
+ printk("\n");
+}
+#endif
+
+#if DEBUG
+
+static void print_objinfo(kmem_cache_t *cachep, void *objp, int lines)
+{
+ int i, size;
+ char *realobj;
+
+ if (cachep->flags & SLAB_RED_ZONE) {
+ printk(KERN_ERR "Redzone: 0x%lx/0x%lx.\n",
+ *dbg_redzone1(cachep, objp),
+ *dbg_redzone2(cachep, objp));
+ }
+
+ if (cachep->flags & SLAB_STORE_USER) {
+ printk(KERN_ERR "Last user: [<%p>]",
+ *dbg_userword(cachep, objp));
+ print_symbol("(%s)",
+ (unsigned long)*dbg_userword(cachep, objp));
+ printk("\n");
+ }
+ realobj = (char*)objp+obj_dbghead(cachep);
+ size = obj_reallen(cachep);
+ for (i=0; i<size && lines;i+=16, lines--) {
+ int limit;
+ limit = 16;
+ if (i+limit > size)
+ limit = size-i;
+ dump_line(realobj, i, limit);
+ }
+}
+
+static void check_poison_obj(kmem_cache_t *cachep, void *objp)
+{
+ char *realobj;
+ int size, i;
+ int lines = 0;
+
+ realobj = (char*)objp+obj_dbghead(cachep);
+ size = obj_reallen(cachep);
+
+ for (i=0;i<size;i++) {
+ char exp = POISON_FREE;
+ if (i == size-1)
+ exp = POISON_END;
+ if (realobj[i] != exp) {
+ int limit;
+ /* Mismatch ! */
+ /* Print header */
+ if (lines == 0) {
+ printk(KERN_ERR "Slab corruption: start=%p, len=%d\n",
+ realobj, size);
+ print_objinfo(cachep, objp, 0);
+ }
+ /* Hexdump the affected line */
+ i = (i/16)*16;
+ limit = 16;
+ if (i+limit > size)
+ limit = size-i;
+ dump_line(realobj, i, limit);
+ i += 16;
+ lines++;
+ /* Limit to 5 lines */
+ if (lines > 5)
+ break;
+ }
+ }
+ if (lines != 0) {
+ /* Print some data about the neighboring objects, if they
+ * exist:
+ */
+ struct slab *slabp = GET_PAGE_SLAB(virt_to_page(objp));
+ int objnr;
+
+ objnr = (objp-slabp->s_mem)/cachep->objsize;
+ if (objnr) {
+ objp = slabp->s_mem+(objnr-1)*cachep->objsize;
+ realobj = (char*)objp+obj_dbghead(cachep);
+ printk(KERN_ERR "Prev obj: start=%p, len=%d\n",
+ realobj, size);
+ print_objinfo(cachep, objp, 2);
+ }
+ if (objnr+1 < cachep->num) {
+ objp = slabp->s_mem+(objnr+1)*cachep->objsize;
+ realobj = (char*)objp+obj_dbghead(cachep);
+ printk(KERN_ERR "Next obj: start=%p, len=%d\n",
+ realobj, size);
+ print_objinfo(cachep, objp, 2);
+ }
+ }
+}
+#endif
+
+/* Destroy all the objs in a slab, and release the mem back to the system.
+ * Before calling the slab must have been unlinked from the cache.
+ * The cache-lock is not held/needed.
+ */
+static void slab_destroy (kmem_cache_t *cachep, struct slab *slabp)
+{
+ void *addr = slabp->s_mem - slabp->colouroff;
+
+#if DEBUG
+ int i;
+ for (i = 0; i < cachep->num; i++) {
+ void *objp = slabp->s_mem + cachep->objsize * i;
+
+ if (cachep->flags & SLAB_POISON) {
+#ifdef CONFIG_DEBUG_PAGEALLOC
+ if ((cachep->objsize%PAGE_SIZE)==0 && OFF_SLAB(cachep))
+ kernel_map_pages(virt_to_page(objp), cachep->objsize/PAGE_SIZE,1);
+ else
+ check_poison_obj(cachep, objp);
+#else
+ check_poison_obj(cachep, objp);
+#endif
+ }
+ if (cachep->flags & SLAB_RED_ZONE) {
+ if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
+ slab_error(cachep, "start of a freed object "
+ "was overwritten");
+ if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
+ slab_error(cachep, "end of a freed object "
+ "was overwritten");
+ }
+ if (cachep->dtor && !(cachep->flags & SLAB_POISON))
+ (cachep->dtor)(objp+obj_dbghead(cachep), cachep, 0);
+ }
+#else
+ if (cachep->dtor) {
+ int i;
+ for (i = 0; i < cachep->num; i++) {
+ void* objp = slabp->s_mem+cachep->objsize*i;
+ (cachep->dtor)(objp, cachep, 0);
+ }
+ }
+#endif
+
+ if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) {
+ struct slab_rcu *slab_rcu;
+
+ slab_rcu = (struct slab_rcu *) slabp;
+ slab_rcu->cachep = cachep;
+ slab_rcu->addr = addr;
+ call_rcu(&slab_rcu->head, kmem_rcu_free);
+ } else {
+ kmem_freepages(cachep, addr);
+ if (OFF_SLAB(cachep))
+ kmem_cache_free(cachep->slabp_cache, slabp);
+ }
+}
+
+/**
+ * kmem_cache_create - Create a cache.
+ * @name: A string which is used in /proc/slabinfo to identify this cache.
+ * @size: The size of objects to be created in this cache.
+ * @align: The required alignment for the objects.
+ * @flags: SLAB flags
+ * @ctor: A constructor for the objects.
+ * @dtor: A destructor for the objects.
+ *
+ * Returns a ptr to the cache on success, NULL on failure.
+ * Cannot be called within a int, but can be interrupted.
+ * The @ctor is run when new pages are allocated by the cache
+ * and the @dtor is run before the pages are handed back.
+ *
+ * @name must be valid until the cache is destroyed. This implies that
+ * the module calling this has to destroy the cache before getting
+ * unloaded.
+ *
+ * The flags are
+ *
+ * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
+ * to catch references to uninitialised memory.
+ *
+ * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
+ * for buffer overruns.
+ *
+ * %SLAB_NO_REAP - Don't automatically reap this cache when we're under
+ * memory pressure.
+ *
+ * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
+ * cacheline. This can be beneficial if you're counting cycles as closely
+ * as davem.
+ */
+kmem_cache_t *
+kmem_cache_create (const char *name, size_t size, size_t align,
+ unsigned long flags, void (*ctor)(void*, kmem_cache_t *, unsigned long),
+ void (*dtor)(void*, kmem_cache_t *, unsigned long))
+{
+ size_t left_over, slab_size, ralign;
+ kmem_cache_t *cachep = NULL;
+
+ /*
+ * Sanity checks... these are all serious usage bugs.
+ */
+ if ((!name) ||
+ in_interrupt() ||
+ (size < BYTES_PER_WORD) ||
+ (size > (1<<MAX_OBJ_ORDER)*PAGE_SIZE) ||
+ (dtor && !ctor)) {
+ printk(KERN_ERR "%s: Early error in slab %s\n",
+ __FUNCTION__, name);
+ BUG();
+ }
+
+#if DEBUG
+ WARN_ON(strchr(name, ' ')); /* It confuses parsers */
+ if ((flags & SLAB_DEBUG_INITIAL) && !ctor) {
+ /* No constructor, but inital state check requested */
+ printk(KERN_ERR "%s: No con, but init state check "
+ "requested - %s\n", __FUNCTION__, name);
+ flags &= ~SLAB_DEBUG_INITIAL;
+ }
+
+#if FORCED_DEBUG
+ /*
+ * Enable redzoning and last user accounting, except for caches with
+ * large objects, if the increased size would increase the object size
+ * above the next power of two: caches with object sizes just above a
+ * power of two have a significant amount of internal fragmentation.
+ */
+ if ((size < 4096 || fls(size-1) == fls(size-1+3*BYTES_PER_WORD)))
+ flags |= SLAB_RED_ZONE|SLAB_STORE_USER;
+ if (!(flags & SLAB_DESTROY_BY_RCU))
+ flags |= SLAB_POISON;
+#endif
+ if (flags & SLAB_DESTROY_BY_RCU)
+ BUG_ON(flags & SLAB_POISON);
+#endif
+ if (flags & SLAB_DESTROY_BY_RCU)
+ BUG_ON(dtor);
+
+ /*
+ * Always checks flags, a caller might be expecting debug
+ * support which isn't available.
+ */
+ if (flags & ~CREATE_MASK)
+ BUG();
+
+ /* Check that size is in terms of words. This is needed to avoid
+ * unaligned accesses for some archs when redzoning is used, and makes
+ * sure any on-slab bufctl's are also correctly aligned.
+ */
+ if (size & (BYTES_PER_WORD-1)) {
+ size += (BYTES_PER_WORD-1);
+ size &= ~(BYTES_PER_WORD-1);
+ }
+
+ /* calculate out the final buffer alignment: */
+ /* 1) arch recommendation: can be overridden for debug */
+ if (flags & SLAB_HWCACHE_ALIGN) {
+ /* Default alignment: as specified by the arch code.
+ * Except if an object is really small, then squeeze multiple
+ * objects into one cacheline.
+ */
+ ralign = cache_line_size();
+ while (size <= ralign/2)
+ ralign /= 2;
+ } else {
+ ralign = BYTES_PER_WORD;
+ }
+ /* 2) arch mandated alignment: disables debug if necessary */
+ if (ralign < ARCH_SLAB_MINALIGN) {
+ ralign = ARCH_SLAB_MINALIGN;
+ if (ralign > BYTES_PER_WORD)
+ flags &= ~(SLAB_RED_ZONE|SLAB_STORE_USER);
+ }
+ /* 3) caller mandated alignment: disables debug if necessary */
+ if (ralign < align) {
+ ralign = align;
+ if (ralign > BYTES_PER_WORD)
+ flags &= ~(SLAB_RED_ZONE|SLAB_STORE_USER);
+ }
+ /* 4) Store it. Note that the debug code below can reduce
+ * the alignment to BYTES_PER_WORD.
+ */
+ align = ralign;
+
+ /* Get cache's description obj. */
+ cachep = (kmem_cache_t *) kmem_cache_alloc(&cache_cache, SLAB_KERNEL);
+ if (!cachep)
+ goto opps;
+ memset(cachep, 0, sizeof(kmem_cache_t));
+
+#if DEBUG
+ cachep->reallen = size;
+
+ if (flags & SLAB_RED_ZONE) {
+ /* redzoning only works with word aligned caches */
+ align = BYTES_PER_WORD;
+
+ /* add space for red zone words */
+ cachep->dbghead += BYTES_PER_WORD;
+ size += 2*BYTES_PER_WORD;
+ }
+ if (flags & SLAB_STORE_USER) {
+ /* user store requires word alignment and
+ * one word storage behind the end of the real
+ * object.
+ */
+ align = BYTES_PER_WORD;
+ size += BYTES_PER_WORD;
+ }
+#if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC)
+ if (size > 128 && cachep->reallen > cache_line_size() && size < PAGE_SIZE) {
+ cachep->dbghead += PAGE_SIZE - size;
+ size = PAGE_SIZE;
+ }
+#endif
+#endif
+
+ /* Determine if the slab management is 'on' or 'off' slab. */
+ if (size >= (PAGE_SIZE>>3))
+ /*
+ * Size is large, assume best to place the slab management obj
+ * off-slab (should allow better packing of objs).
+ */
+ flags |= CFLGS_OFF_SLAB;
+
+ size = ALIGN(size, align);
+
+ if ((flags & SLAB_RECLAIM_ACCOUNT) && size <= PAGE_SIZE) {
+ /*
+ * A VFS-reclaimable slab tends to have most allocations
+ * as GFP_NOFS and we really don't want to have to be allocating
+ * higher-order pages when we are unable to shrink dcache.
+ */
+ cachep->gfporder = 0;
+ cache_estimate(cachep->gfporder, size, align, flags,
+ &left_over, &cachep->num);
+ } else {
+ /*
+ * Calculate size (in pages) of slabs, and the num of objs per
+ * slab. This could be made much more intelligent. For now,
+ * try to avoid using high page-orders for slabs. When the
+ * gfp() funcs are more friendly towards high-order requests,
+ * this should be changed.
+ */
+ do {
+ unsigned int break_flag = 0;
+cal_wastage:
+ cache_estimate(cachep->gfporder, size, align, flags,
+ &left_over, &cachep->num);
+ if (break_flag)
+ break;
+ if (cachep->gfporder >= MAX_GFP_ORDER)
+ break;
+ if (!cachep->num)
+ goto next;
+ if (flags & CFLGS_OFF_SLAB &&
+ cachep->num > offslab_limit) {
+ /* This num of objs will cause problems. */
+ cachep->gfporder--;
+ break_flag++;
+ goto cal_wastage;
+ }
+
+ /*
+ * Large num of objs is good, but v. large slabs are
+ * currently bad for the gfp()s.
+ */
+ if (cachep->gfporder >= slab_break_gfp_order)
+ break;
+
+ if ((left_over*8) <= (PAGE_SIZE<<cachep->gfporder))
+ break; /* Acceptable internal fragmentation. */
+next:
+ cachep->gfporder++;
+ } while (1);
+ }
+
+ if (!cachep->num) {
+ printk("kmem_cache_create: couldn't create cache %s.\n", name);
+ kmem_cache_free(&cache_cache, cachep);
+ cachep = NULL;
+ goto opps;
+ }
+ slab_size = ALIGN(cachep->num*sizeof(kmem_bufctl_t)
+ + sizeof(struct slab), align);
+
+ /*
+ * If the slab has been placed off-slab, and we have enough space then
+ * move it on-slab. This is at the expense of any extra colouring.
+ */
+ if (flags & CFLGS_OFF_SLAB && left_over >= slab_size) {
+ flags &= ~CFLGS_OFF_SLAB;
+ left_over -= slab_size;
+ }
+
+ 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->colour_off = cache_line_size();
+ /* Offset must be a multiple of the alignment. */
+ if (cachep->colour_off < align)
+ cachep->colour_off = align;
+ cachep->colour = left_over/cachep->colour_off;
+ cachep->slab_size = slab_size;
+ cachep->flags = flags;
+ cachep->gfpflags = 0;
+ if (flags & SLAB_CACHE_DMA)
+ cachep->gfpflags |= GFP_DMA;
+ spin_lock_init(&cachep->spinlock);
+ cachep->objsize = size;
+ /* NUMA */
+ INIT_LIST_HEAD(&cachep->lists.slabs_full);
+ INIT_LIST_HEAD(&cachep->lists.slabs_partial);
+ INIT_LIST_HEAD(&cachep->lists.slabs_free);
+
+ if (flags & CFLGS_OFF_SLAB)
+ cachep->slabp_cache = kmem_find_general_cachep(slab_size,0);
+ cachep->ctor = ctor;
+ cachep->dtor = dtor;
+ cachep->name = name;
+
+ /* Don't let CPUs to come and go */
+ lock_cpu_hotplug();
+
+ if (g_cpucache_up == FULL) {
+ enable_cpucache(cachep);
+ } else {
+ if (g_cpucache_up == NONE) {
+ /* Note: the first kmem_cache_create must create
+ * the cache that's used by kmalloc(24), otherwise
+ * the creation of further caches will BUG().
+ */
+ cachep->array[smp_processor_id()] = &initarray_generic.cache;
+ g_cpucache_up = PARTIAL;
+ } else {
+ cachep->array[smp_processor_id()] = kmalloc(sizeof(struct arraycache_init),GFP_KERNEL);
+ }
+ BUG_ON(!ac_data(cachep));
+ ac_data(cachep)->avail = 0;
+ ac_data(cachep)->limit = BOOT_CPUCACHE_ENTRIES;
+ ac_data(cachep)->batchcount = 1;
+ ac_data(cachep)->touched = 0;
+ cachep->batchcount = 1;
+ cachep->limit = BOOT_CPUCACHE_ENTRIES;
+ cachep->free_limit = (1+num_online_cpus())*cachep->batchcount
+ + cachep->num;
+ }
+
+ cachep->lists.next_reap = jiffies + REAPTIMEOUT_LIST3 +
+ ((unsigned long)cachep)%REAPTIMEOUT_LIST3;
+
+ /* Need the semaphore to access the chain. */
+ down(&cache_chain_sem);
+ {
+ struct list_head *p;
+ mm_segment_t old_fs;
+
+ old_fs = get_fs();
+ set_fs(KERNEL_DS);
+ list_for_each(p, &cache_chain) {
+ kmem_cache_t *pc = list_entry(p, kmem_cache_t, next);
+ char tmp;
+ /* This happens when the module gets unloaded and doesn't
+ destroy its slab cache and noone else reuses the vmalloc
+ area of the module. Print a warning. */
+ if (__get_user(tmp,pc->name)) {
+ printk("SLAB: cache with size %d has lost its name\n",
+ pc->objsize);
+ continue;
+ }
+ if (!strcmp(pc->name,name)) {
+ printk("kmem_cache_create: duplicate cache %s\n",name);
+ up(&cache_chain_sem);
+ unlock_cpu_hotplug();
+ BUG();
+ }
+ }
+ set_fs(old_fs);
+ }
+
+ /* cache setup completed, link it into the list */
+ list_add(&cachep->next, &cache_chain);
+ up(&cache_chain_sem);
+ unlock_cpu_hotplug();
+opps:
+ if (!cachep && (flags & SLAB_PANIC))
+ panic("kmem_cache_create(): failed to create slab `%s'\n",
+ name);
+ return cachep;
+}
+EXPORT_SYMBOL(kmem_cache_create);
+
+#if DEBUG
+static void check_irq_off(void)
+{
+ BUG_ON(!irqs_disabled());
+}
+
+static void check_irq_on(void)
+{
+ BUG_ON(irqs_disabled());
+}
+
+static void check_spinlock_acquired(kmem_cache_t *cachep)
+{
+#ifdef CONFIG_SMP
+ check_irq_off();
+ BUG_ON(spin_trylock(&cachep->spinlock));
+#endif
+}
+#else
+#define check_irq_off() do { } while(0)
+#define check_irq_on() do { } while(0)
+#define check_spinlock_acquired(x) do { } while(0)
+#endif
+
+/*
+ * Waits for all CPUs to execute func().
+ */
+static void smp_call_function_all_cpus(void (*func) (void *arg), void *arg)
+{
+ check_irq_on();
+ preempt_disable();
+
+ local_irq_disable();
+ func(arg);
+ local_irq_enable();
+
+ if (smp_call_function(func, arg, 1, 1))
+ BUG();
+
+ preempt_enable();
+}
+
+static void drain_array_locked(kmem_cache_t* cachep,
+ struct array_cache *ac, int force);
+
+static void do_drain(void *arg)
+{
+ kmem_cache_t *cachep = (kmem_cache_t*)arg;
+ struct array_cache *ac;
+
+ check_irq_off();
+ ac = ac_data(cachep);
+ spin_lock(&cachep->spinlock);
+ free_block(cachep, &ac_entry(ac)[0], ac->avail);
+ spin_unlock(&cachep->spinlock);
+ ac->avail = 0;
+}
+
+static void drain_cpu_caches(kmem_cache_t *cachep)
+{
+ smp_call_function_all_cpus(do_drain, cachep);
+ check_irq_on();
+ spin_lock_irq(&cachep->spinlock);
+ if (cachep->lists.shared)
+ drain_array_locked(cachep, cachep->lists.shared, 1);
+ spin_unlock_irq(&cachep->spinlock);
+}
+
+
+/* NUMA shrink all list3s */
+static int __cache_shrink(kmem_cache_t *cachep)
+{
+ struct slab *slabp;
+ int ret;
+
+ drain_cpu_caches(cachep);
+
+ check_irq_on();
+ spin_lock_irq(&cachep->spinlock);
+
+ for(;;) {
+ struct list_head *p;
+
+ p = cachep->lists.slabs_free.prev;
+ if (p == &cachep->lists.slabs_free)
+ break;
+
+ slabp = list_entry(cachep->lists.slabs_free.prev, struct slab, list);
+#if DEBUG
+ if (slabp->inuse)
+ BUG();
+#endif
+ list_del(&slabp->list);
+
+ cachep->lists.free_objects -= cachep->num;
+ spin_unlock_irq(&cachep->spinlock);
+ slab_destroy(cachep, slabp);
+ spin_lock_irq(&cachep->spinlock);
+ }
+ ret = !list_empty(&cachep->lists.slabs_full) ||
+ !list_empty(&cachep->lists.slabs_partial);
+ spin_unlock_irq(&cachep->spinlock);
+ return ret;
+}
+
+/**
+ * kmem_cache_shrink - Shrink a cache.
+ * @cachep: The cache to shrink.
+ *
+ * Releases as many slabs as possible for a cache.
+ * To help debugging, a zero exit status indicates all slabs were released.
+ */
+int kmem_cache_shrink(kmem_cache_t *cachep)
+{
+ if (!cachep || in_interrupt())
+ BUG();
+
+ return __cache_shrink(cachep);
+}
+EXPORT_SYMBOL(kmem_cache_shrink);
+
+/**
+ * kmem_cache_destroy - delete a cache
+ * @cachep: the cache to destroy
+ *
+ * Remove a kmem_cache_t object from the slab cache.
+ * Returns 0 on success.
+ *
+ * It is expected this function will be called by a module when it is
+ * unloaded. This will remove the cache completely, and avoid a duplicate
+ * cache being allocated each time a module is loaded and unloaded, if the
+ * module doesn't have persistent in-kernel storage across loads and unloads.
+ *
+ * The cache must be empty before calling this function.
+ *
+ * The caller must guarantee that noone will allocate memory from the cache
+ * during the kmem_cache_destroy().
+ */
+int kmem_cache_destroy(kmem_cache_t * cachep)
+{
+ int i;
+
+ if (!cachep || in_interrupt())
+ BUG();
+
+ /* Don't let CPUs to come and go */
+ lock_cpu_hotplug();
+
+ /* Find the cache in the chain of caches. */
+ down(&cache_chain_sem);
+ /*
+ * the chain is never empty, cache_cache is never destroyed
+ */
+ list_del(&cachep->next);
+ up(&cache_chain_sem);
+
+ if (__cache_shrink(cachep)) {
+ slab_error(cachep, "Can't free all objects");
+ down(&cache_chain_sem);
+ list_add(&cachep->next,&cache_chain);
+ up(&cache_chain_sem);
+ unlock_cpu_hotplug();
+ return 1;
+ }
+
+ if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU))
+ synchronize_kernel();
+
+ /* no cpu_online check required here since we clear the percpu
+ * array on cpu offline and set this to NULL.
+ */
+ for (i = 0; i < NR_CPUS; i++)
+ kfree(cachep->array[i]);
+
+ /* NUMA: free the list3 structures */
+ kfree(cachep->lists.shared);
+ cachep->lists.shared = NULL;
+ kmem_cache_free(&cache_cache, cachep);
+
+ unlock_cpu_hotplug();
+
+ return 0;
+}
+EXPORT_SYMBOL(kmem_cache_destroy);
+
+/* Get the memory for a slab management obj. */
+static struct slab* alloc_slabmgmt(kmem_cache_t *cachep,
+ void *objp, int colour_off, unsigned int __nocast local_flags)
+{
+ struct slab *slabp;
+
+ if (OFF_SLAB(cachep)) {
+ /* Slab management obj is off-slab. */
+ slabp = kmem_cache_alloc(cachep->slabp_cache, local_flags);
+ if (!slabp)
+ return NULL;
+ } else {
+ slabp = objp+colour_off;
+ colour_off += cachep->slab_size;
+ }
+ slabp->inuse = 0;
+ slabp->colouroff = colour_off;
+ slabp->s_mem = objp+colour_off;
+
+ return slabp;
+}
+
+static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp)
+{
+ return (kmem_bufctl_t *)(slabp+1);
+}
+
+static void cache_init_objs(kmem_cache_t *cachep,
+ struct slab *slabp, unsigned long ctor_flags)
+{
+ int i;
+
+ for (i = 0; i < cachep->num; i++) {
+ void* objp = slabp->s_mem+cachep->objsize*i;
+#if DEBUG
+ /* need to poison the objs? */
+ if (cachep->flags & SLAB_POISON)
+ poison_obj(cachep, objp, POISON_FREE);
+ if (cachep->flags & SLAB_STORE_USER)
+ *dbg_userword(cachep, objp) = NULL;
+
+ if (cachep->flags & SLAB_RED_ZONE) {
+ *dbg_redzone1(cachep, objp) = RED_INACTIVE;
+ *dbg_redzone2(cachep, objp) = RED_INACTIVE;
+ }
+ /*
+ * Constructors are not allowed to allocate memory from
+ * the same cache which they are a constructor for.
+ * Otherwise, deadlock. They must also be threaded.
+ */
+ if (cachep->ctor && !(cachep->flags & SLAB_POISON))
+ cachep->ctor(objp+obj_dbghead(cachep), cachep, ctor_flags);
+
+ if (cachep->flags & SLAB_RED_ZONE) {
+ if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
+ slab_error(cachep, "constructor overwrote the"
+ " end of an object");
+ if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
+ slab_error(cachep, "constructor overwrote the"
+ " start of an object");
+ }
+ if ((cachep->objsize % PAGE_SIZE) == 0 && OFF_SLAB(cachep) && cachep->flags & SLAB_POISON)
+ kernel_map_pages(virt_to_page(objp), cachep->objsize/PAGE_SIZE, 0);
+#else
+ if (cachep->ctor)
+ cachep->ctor(objp, cachep, ctor_flags);
+#endif
+ slab_bufctl(slabp)[i] = i+1;
+ }
+ slab_bufctl(slabp)[i-1] = BUFCTL_END;
+ slabp->free = 0;
+}
+
+static void kmem_flagcheck(kmem_cache_t *cachep, unsigned int flags)
+{
+ if (flags & SLAB_DMA) {
+ if (!(cachep->gfpflags & GFP_DMA))
+ BUG();
+ } else {
+ if (cachep->gfpflags & GFP_DMA)
+ BUG();
+ }
+}
+
+static void set_slab_attr(kmem_cache_t *cachep, struct slab *slabp, void *objp)
+{
+ int i;
+ struct page *page;
+
+ /* Nasty!!!!!! I hope this is OK. */
+ i = 1 << cachep->gfporder;
+ page = virt_to_page(objp);
+ do {
+ SET_PAGE_CACHE(page, cachep);
+ SET_PAGE_SLAB(page, slabp);
+ page++;
+ } while (--i);
+}
+
+/*
+ * Grow (by 1) the number of slabs within a cache. This is called by
+ * kmem_cache_alloc() when there are no active objs left in a cache.
+ */
+static int cache_grow(kmem_cache_t *cachep, unsigned int __nocast flags, int nodeid)
+{
+ struct slab *slabp;
+ void *objp;
+ size_t offset;
+ unsigned int local_flags;
+ unsigned long ctor_flags;
+
+ /* Be lazy and only check for valid flags here,
+ * keeping it out of the critical path in kmem_cache_alloc().
+ */
+ if (flags & ~(SLAB_DMA|SLAB_LEVEL_MASK|SLAB_NO_GROW))
+ BUG();
+ if (flags & SLAB_NO_GROW)
+ return 0;
+
+ ctor_flags = SLAB_CTOR_CONSTRUCTOR;
+ local_flags = (flags & SLAB_LEVEL_MASK);
+ if (!(local_flags & __GFP_WAIT))
+ /*
+ * Not allowed to sleep. Need to tell a constructor about
+ * this - it might need to know...
+ */
+ ctor_flags |= SLAB_CTOR_ATOMIC;
+
+ /* About to mess with non-constant members - lock. */
+ check_irq_off();
+ spin_lock(&cachep->spinlock);
+
+ /* Get colour for the slab, and cal the next value. */
+ offset = cachep->colour_next;
+ cachep->colour_next++;
+ if (cachep->colour_next >= cachep->colour)
+ cachep->colour_next = 0;
+ offset *= cachep->colour_off;
+
+ spin_unlock(&cachep->spinlock);
+
+ if (local_flags & __GFP_WAIT)
+ local_irq_enable();
+
+ /*
+ * The test for missing atomic flag is performed here, rather than
+ * the more obvious place, simply to reduce the critical path length
+ * in kmem_cache_alloc(). If a caller is seriously mis-behaving they
+ * will eventually be caught here (where it matters).
+ */
+ kmem_flagcheck(cachep, flags);
+
+
+ /* Get mem for the objs. */
+ if (!(objp = kmem_getpages(cachep, flags, nodeid)))
+ goto failed;
+
+ /* Get slab management. */
+ if (!(slabp = alloc_slabmgmt(cachep, objp, offset, local_flags)))
+ goto opps1;
+
+ set_slab_attr(cachep, slabp, objp);
+
+ cache_init_objs(cachep, slabp, ctor_flags);
+
+ if (local_flags & __GFP_WAIT)
+ local_irq_disable();
+ check_irq_off();
+ spin_lock(&cachep->spinlock);
+
+ /* Make slab active. */
+ list_add_tail(&slabp->list, &(list3_data(cachep)->slabs_free));
+ STATS_INC_GROWN(cachep);
+ list3_data(cachep)->free_objects += cachep->num;
+ spin_unlock(&cachep->spinlock);
+ return 1;
+opps1:
+ kmem_freepages(cachep, objp);
+failed:
+ if (local_flags & __GFP_WAIT)
+ local_irq_disable();
+ return 0;
+}
+
+#if DEBUG
+
+/*
+ * Perform extra freeing checks:
+ * - detect bad pointers.
+ * - POISON/RED_ZONE checking
+ * - destructor calls, for caches with POISON+dtor
+ */
+static void kfree_debugcheck(const void *objp)
+{
+ struct page *page;
+
+ if (!virt_addr_valid(objp)) {
+ printk(KERN_ERR "kfree_debugcheck: out of range ptr %lxh.\n",
+ (unsigned long)objp);
+ BUG();
+ }
+ page = virt_to_page(objp);
+ if (!PageSlab(page)) {
+ printk(KERN_ERR "kfree_debugcheck: bad ptr %lxh.\n", (unsigned long)objp);
+ BUG();
+ }
+}
+
+static void *cache_free_debugcheck(kmem_cache_t *cachep, void *objp,
+ void *caller)
+{
+ struct page *page;
+ unsigned int objnr;
+ struct slab *slabp;
+
+ objp -= obj_dbghead(cachep);
+ kfree_debugcheck(objp);
+ page = virt_to_page(objp);
+
+ if (GET_PAGE_CACHE(page) != cachep) {
+ printk(KERN_ERR "mismatch in kmem_cache_free: expected cache %p, got %p\n",
+ GET_PAGE_CACHE(page),cachep);
+ printk(KERN_ERR "%p is %s.\n", cachep, cachep->name);
+ printk(KERN_ERR "%p is %s.\n", GET_PAGE_CACHE(page), GET_PAGE_CACHE(page)->name);
+ WARN_ON(1);
+ }
+ slabp = GET_PAGE_SLAB(page);
+
+ if (cachep->flags & SLAB_RED_ZONE) {
+ if (*dbg_redzone1(cachep, objp) != RED_ACTIVE || *dbg_redzone2(cachep, objp) != RED_ACTIVE) {
+ slab_error(cachep, "double free, or memory outside"
+ " object was overwritten");
+ printk(KERN_ERR "%p: redzone 1: 0x%lx, redzone 2: 0x%lx.\n",
+ objp, *dbg_redzone1(cachep, objp), *dbg_redzone2(cachep, objp));
+ }
+ *dbg_redzone1(cachep, objp) = RED_INACTIVE;
+ *dbg_redzone2(cachep, objp) = RED_INACTIVE;
+ }
+ if (cachep->flags & SLAB_STORE_USER)
+ *dbg_userword(cachep, objp) = caller;
+
+ objnr = (objp-slabp->s_mem)/cachep->objsize;
+
+ BUG_ON(objnr >= cachep->num);
+ BUG_ON(objp != slabp->s_mem + objnr*cachep->objsize);
+
+ if (cachep->flags & SLAB_DEBUG_INITIAL) {
+ /* Need to call the slab's constructor so the
+ * caller can perform a verify of its state (debugging).
+ * Called without the cache-lock held.
+ */
+ cachep->ctor(objp+obj_dbghead(cachep),
+ cachep, SLAB_CTOR_CONSTRUCTOR|SLAB_CTOR_VERIFY);
+ }
+ if (cachep->flags & SLAB_POISON && cachep->dtor) {
+ /* we want to cache poison the object,
+ * call the destruction callback
+ */
+ cachep->dtor(objp+obj_dbghead(cachep), cachep, 0);
+ }
+ if (cachep->flags & SLAB_POISON) {
+#ifdef CONFIG_DEBUG_PAGEALLOC
+ if ((cachep->objsize % PAGE_SIZE) == 0 && OFF_SLAB(cachep)) {
+ store_stackinfo(cachep, objp, (unsigned long)caller);
+ kernel_map_pages(virt_to_page(objp), cachep->objsize/PAGE_SIZE, 0);
+ } else {
+ poison_obj(cachep, objp, POISON_FREE);
+ }
+#else
+ poison_obj(cachep, objp, POISON_FREE);
+#endif
+ }
+ return objp;
+}
+
+static void check_slabp(kmem_cache_t *cachep, struct slab *slabp)
+{
+ kmem_bufctl_t i;
+ int entries = 0;
+
+ check_spinlock_acquired(cachep);
+ /* Check slab's freelist to see if this obj is there. */
+ for (i = slabp->free; i != BUFCTL_END; i = slab_bufctl(slabp)[i]) {
+ entries++;
+ if (entries > cachep->num || i >= cachep->num)
+ goto bad;
+ }
+ if (entries != cachep->num - slabp->inuse) {
+bad:
+ printk(KERN_ERR "slab: Internal list corruption detected in cache '%s'(%d), slabp %p(%d). Hexdump:\n",
+ cachep->name, cachep->num, slabp, slabp->inuse);
+ for (i=0;i<sizeof(slabp)+cachep->num*sizeof(kmem_bufctl_t);i++) {
+ if ((i%16)==0)
+ printk("\n%03x:", i);
+ printk(" %02x", ((unsigned char*)slabp)[i]);
+ }
+ printk("\n");
+ BUG();
+ }
+}
+#else
+#define kfree_debugcheck(x) do { } while(0)
+#define cache_free_debugcheck(x,objp,z) (objp)
+#define check_slabp(x,y) do { } while(0)
+#endif
+
+static void *cache_alloc_refill(kmem_cache_t *cachep, unsigned int __nocast flags)
+{
+ int batchcount;
+ struct kmem_list3 *l3;
+ struct array_cache *ac;
+
+ check_irq_off();
+ ac = ac_data(cachep);
+retry:
+ batchcount = ac->batchcount;
+ if (!ac->touched && batchcount > BATCHREFILL_LIMIT) {
+ /* if there was little recent activity on this
+ * cache, then perform only a partial refill.
+ * Otherwise we could generate refill bouncing.
+ */
+ batchcount = BATCHREFILL_LIMIT;
+ }
+ l3 = list3_data(cachep);
+
+ BUG_ON(ac->avail > 0);
+ spin_lock(&cachep->spinlock);
+ if (l3->shared) {
+ struct array_cache *shared_array = l3->shared;
+ if (shared_array->avail) {
+ if (batchcount > shared_array->avail)
+ batchcount = shared_array->avail;
+ shared_array->avail -= batchcount;
+ ac->avail = batchcount;
+ memcpy(ac_entry(ac), &ac_entry(shared_array)[shared_array->avail],
+ sizeof(void*)*batchcount);
+ shared_array->touched = 1;
+ goto alloc_done;
+ }
+ }
+ while (batchcount > 0) {
+ struct list_head *entry;
+ struct slab *slabp;
+ /* Get slab alloc is to come from. */
+ entry = l3->slabs_partial.next;
+ if (entry == &l3->slabs_partial) {
+ l3->free_touched = 1;
+ entry = l3->slabs_free.next;
+ if (entry == &l3->slabs_free)
+ goto must_grow;
+ }
+
+ slabp = list_entry(entry, struct slab, list);
+ check_slabp(cachep, slabp);
+ check_spinlock_acquired(cachep);
+ while (slabp->inuse < cachep->num && batchcount--) {
+ kmem_bufctl_t next;
+ STATS_INC_ALLOCED(cachep);
+ STATS_INC_ACTIVE(cachep);
+ STATS_SET_HIGH(cachep);
+
+ /* get obj pointer */
+ ac_entry(ac)[ac->avail++] = slabp->s_mem + slabp->free*cachep->objsize;
+
+ slabp->inuse++;
+ next = slab_bufctl(slabp)[slabp->free];
+#if DEBUG
+ slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE;
+#endif
+ slabp->free = next;
+ }
+ check_slabp(cachep, slabp);
+
+ /* move slabp to correct slabp list: */
+ list_del(&slabp->list);
+ if (slabp->free == BUFCTL_END)
+ list_add(&slabp->list, &l3->slabs_full);
+ else
+ list_add(&slabp->list, &l3->slabs_partial);
+ }
+
+must_grow:
+ l3->free_objects -= ac->avail;
+alloc_done:
+ spin_unlock(&cachep->spinlock);
+
+ if (unlikely(!ac->avail)) {
+ int x;
+ x = cache_grow(cachep, flags, -1);
+
+ // cache_grow can reenable interrupts, then ac could change.
+ ac = ac_data(cachep);
+ if (!x && ac->avail == 0) // no objects in sight? abort
+ return NULL;
+
+ if (!ac->avail) // objects refilled by interrupt?
+ goto retry;
+ }
+ ac->touched = 1;
+ return ac_entry(ac)[--ac->avail];
+}
+
+static inline void
+cache_alloc_debugcheck_before(kmem_cache_t *cachep, unsigned int __nocast flags)
+{
+ might_sleep_if(flags & __GFP_WAIT);
+#if DEBUG
+ kmem_flagcheck(cachep, flags);
+#endif
+}
+
+#if DEBUG
+static void *
+cache_alloc_debugcheck_after(kmem_cache_t *cachep,
+ unsigned long flags, void *objp, void *caller)
+{
+ if (!objp)
+ return objp;
+ if (cachep->flags & SLAB_POISON) {
+#ifdef CONFIG_DEBUG_PAGEALLOC
+ if ((cachep->objsize % PAGE_SIZE) == 0 && OFF_SLAB(cachep))
+ kernel_map_pages(virt_to_page(objp), cachep->objsize/PAGE_SIZE, 1);
+ else
+ check_poison_obj(cachep, objp);
+#else
+ check_poison_obj(cachep, objp);
+#endif
+ poison_obj(cachep, objp, POISON_INUSE);
+ }
+ if (cachep->flags & SLAB_STORE_USER)
+ *dbg_userword(cachep, objp) = caller;
+
+ if (cachep->flags & SLAB_RED_ZONE) {
+ if (*dbg_redzone1(cachep, objp) != RED_INACTIVE || *dbg_redzone2(cachep, objp) != RED_INACTIVE) {
+ slab_error(cachep, "double free, or memory outside"
+ " object was overwritten");
+ printk(KERN_ERR "%p: redzone 1: 0x%lx, redzone 2: 0x%lx.\n",
+ objp, *dbg_redzone1(cachep, objp), *dbg_redzone2(cachep, objp));
+ }
+ *dbg_redzone1(cachep, objp) = RED_ACTIVE;
+ *dbg_redzone2(cachep, objp) = RED_ACTIVE;
+ }
+ objp += obj_dbghead(cachep);
+ if (cachep->ctor && cachep->flags & SLAB_POISON) {
+ unsigned long ctor_flags = SLAB_CTOR_CONSTRUCTOR;
+
+ if (!(flags & __GFP_WAIT))
+ ctor_flags |= SLAB_CTOR_ATOMIC;
+
+ cachep->ctor(objp, cachep, ctor_flags);
+ }
+ return objp;
+}
+#else
+#define cache_alloc_debugcheck_after(a,b,objp,d) (objp)
+#endif
+
+
+static inline void *__cache_alloc(kmem_cache_t *cachep, unsigned int __nocast flags)
+{
+ unsigned long save_flags;
+ void* objp;
+ struct array_cache *ac;
+
+ cache_alloc_debugcheck_before(cachep, flags);
+
+ local_irq_save(save_flags);
+ ac = ac_data(cachep);
+ if (likely(ac->avail)) {
+ STATS_INC_ALLOCHIT(cachep);
+ ac->touched = 1;
+ objp = ac_entry(ac)[--ac->avail];
+ } else {
+ STATS_INC_ALLOCMISS(cachep);
+ objp = cache_alloc_refill(cachep, flags);
+ }
+ local_irq_restore(save_flags);
+ objp = cache_alloc_debugcheck_after(cachep, flags, objp, __builtin_return_address(0));
+ return objp;
+}
+
+/*
+ * NUMA: different approach needed if the spinlock is moved into
+ * the l3 structure
+ */
+
+static void free_block(kmem_cache_t *cachep, void **objpp, int nr_objects)
+{
+ int i;
+
+ check_spinlock_acquired(cachep);
+
+ /* NUMA: move add into loop */
+ cachep->lists.free_objects += nr_objects;
+
+ for (i = 0; i < nr_objects; i++) {
+ void *objp = objpp[i];
+ struct slab *slabp;
+ unsigned int objnr;
+
+ slabp = GET_PAGE_SLAB(virt_to_page(objp));
+ list_del(&slabp->list);
+ objnr = (objp - slabp->s_mem) / cachep->objsize;
+ check_slabp(cachep, slabp);
+#if DEBUG
+ if (slab_bufctl(slabp)[objnr] != BUFCTL_FREE) {
+ printk(KERN_ERR "slab: double free detected in cache '%s', objp %p.\n",
+ cachep->name, objp);
+ BUG();
+ }
+#endif
+ slab_bufctl(slabp)[objnr] = slabp->free;
+ slabp->free = objnr;
+ STATS_DEC_ACTIVE(cachep);
+ slabp->inuse--;
+ check_slabp(cachep, slabp);
+
+ /* fixup slab chains */
+ if (slabp->inuse == 0) {
+ if (cachep->lists.free_objects > cachep->free_limit) {
+ cachep->lists.free_objects -= cachep->num;
+ slab_destroy(cachep, slabp);
+ } else {
+ list_add(&slabp->list,
+ &list3_data_ptr(cachep, objp)->slabs_free);
+ }
+ } else {
+ /* Unconditionally move a slab to the end of the
+ * partial list on free - maximum time for the
+ * other objects to be freed, too.
+ */
+ list_add_tail(&slabp->list,
+ &list3_data_ptr(cachep, objp)->slabs_partial);
+ }
+ }
+}
+
+static void cache_flusharray(kmem_cache_t *cachep, struct array_cache *ac)
+{
+ int batchcount;
+
+ batchcount = ac->batchcount;
+#if DEBUG
+ BUG_ON(!batchcount || batchcount > ac->avail);
+#endif
+ check_irq_off();
+ spin_lock(&cachep->spinlock);
+ if (cachep->lists.shared) {
+ struct array_cache *shared_array = cachep->lists.shared;
+ int max = shared_array->limit-shared_array->avail;
+ if (max) {
+ if (batchcount > max)
+ batchcount = max;
+ memcpy(&ac_entry(shared_array)[shared_array->avail],
+ &ac_entry(ac)[0],
+ sizeof(void*)*batchcount);
+ shared_array->avail += batchcount;
+ goto free_done;
+ }
+ }
+
+ free_block(cachep, &ac_entry(ac)[0], batchcount);
+free_done:
+#if STATS
+ {
+ int i = 0;
+ struct list_head *p;
+
+ p = list3_data(cachep)->slabs_free.next;
+ while (p != &(list3_data(cachep)->slabs_free)) {
+ struct slab *slabp;
+
+ slabp = list_entry(p, struct slab, list);
+ BUG_ON(slabp->inuse);
+
+ i++;
+ p = p->next;
+ }
+ STATS_SET_FREEABLE(cachep, i);
+ }
+#endif
+ spin_unlock(&cachep->spinlock);
+ ac->avail -= batchcount;
+ memmove(&ac_entry(ac)[0], &ac_entry(ac)[batchcount],
+ sizeof(void*)*ac->avail);
+}
+
+/*
+ * __cache_free
+ * Release an obj back to its cache. If the obj has a constructed
+ * state, it must be in this state _before_ it is released.
+ *
+ * Called with disabled ints.
+ */
+static inline void __cache_free(kmem_cache_t *cachep, void *objp)
+{
+ struct array_cache *ac = ac_data(cachep);
+
+ check_irq_off();
+ objp = cache_free_debugcheck(cachep, objp, __builtin_return_address(0));
+
+ if (likely(ac->avail < ac->limit)) {
+ STATS_INC_FREEHIT(cachep);
+ ac_entry(ac)[ac->avail++] = objp;
+ return;
+ } else {
+ STATS_INC_FREEMISS(cachep);
+ cache_flusharray(cachep, ac);
+ ac_entry(ac)[ac->avail++] = objp;
+ }
+}
+
+/**
+ * kmem_cache_alloc - Allocate an object
+ * @cachep: The cache to allocate from.
+ * @flags: See kmalloc().
+ *
+ * Allocate an object from this cache. The flags are only relevant
+ * if the cache has no available objects.
+ */
+void *kmem_cache_alloc(kmem_cache_t *cachep, unsigned int __nocast flags)
+{
+ return __cache_alloc(cachep, flags);
+}
+EXPORT_SYMBOL(kmem_cache_alloc);
+
+/**
+ * kmem_ptr_validate - check if an untrusted pointer might
+ * be a slab entry.
+ * @cachep: the cache we're checking against
+ * @ptr: pointer to validate
+ *
+ * This verifies that the untrusted pointer looks sane:
+ * it is _not_ a guarantee that the pointer is actually
+ * part of the slab cache in question, but it at least
+ * validates that the pointer can be dereferenced and
+ * looks half-way sane.
+ *
+ * Currently only used for dentry validation.
+ */
+int fastcall kmem_ptr_validate(kmem_cache_t *cachep, void *ptr)
+{
+ unsigned long addr = (unsigned long) ptr;
+ unsigned long min_addr = PAGE_OFFSET;
+ unsigned long align_mask = BYTES_PER_WORD-1;
+ unsigned long size = cachep->objsize;
+ struct page *page;
+
+ if (unlikely(addr < min_addr))
+ goto out;
+ if (unlikely(addr > (unsigned long)high_memory - size))
+ goto out;
+ if (unlikely(addr & align_mask))
+ goto out;
+ if (unlikely(!kern_addr_valid(addr)))
+ goto out;
+ if (unlikely(!kern_addr_valid(addr + size - 1)))
+ goto out;
+ page = virt_to_page(ptr);
+ if (unlikely(!PageSlab(page)))
+ goto out;
+ if (unlikely(GET_PAGE_CACHE(page) != cachep))
+ goto out;
+ return 1;
+out:
+ return 0;
+}
+
+#ifdef CONFIG_NUMA
+/**
+ * kmem_cache_alloc_node - Allocate an object on the specified node
+ * @cachep: The cache to allocate from.
+ * @flags: See kmalloc().
+ * @nodeid: node number of the target node.
+ *
+ * Identical to kmem_cache_alloc, except that this function is slow
+ * and can sleep. And it will allocate memory on the given node, which
+ * can improve the performance for cpu bound structures.
+ */
+void *kmem_cache_alloc_node(kmem_cache_t *cachep, int nodeid)
+{
+ int loop;
+ void *objp;
+ struct slab *slabp;
+ kmem_bufctl_t next;
+
+ for (loop = 0;;loop++) {
+ struct list_head *q;
+
+ objp = NULL;
+ check_irq_on();
+ spin_lock_irq(&cachep->spinlock);
+ /* walk through all partial and empty slab and find one
+ * from the right node */
+ list_for_each(q,&cachep->lists.slabs_partial) {
+ slabp = list_entry(q, struct slab, list);
+
+ if (page_to_nid(virt_to_page(slabp->s_mem)) == nodeid ||
+ loop > 2)
+ goto got_slabp;
+ }
+ list_for_each(q, &cachep->lists.slabs_free) {
+ slabp = list_entry(q, struct slab, list);
+
+ if (page_to_nid(virt_to_page(slabp->s_mem)) == nodeid ||
+ loop > 2)
+ goto got_slabp;
+ }
+ spin_unlock_irq(&cachep->spinlock);
+
+ local_irq_disable();
+ if (!cache_grow(cachep, GFP_KERNEL, nodeid)) {
+ local_irq_enable();
+ return NULL;
+ }
+ local_irq_enable();
+ }
+got_slabp:
+ /* found one: allocate object */
+ check_slabp(cachep, slabp);
+ check_spinlock_acquired(cachep);
+
+ STATS_INC_ALLOCED(cachep);
+ STATS_INC_ACTIVE(cachep);
+ STATS_SET_HIGH(cachep);
+ STATS_INC_NODEALLOCS(cachep);
+
+ objp = slabp->s_mem + slabp->free*cachep->objsize;
+
+ slabp->inuse++;
+ next = slab_bufctl(slabp)[slabp->free];
+#if DEBUG
+ slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE;
+#endif
+ slabp->free = next;
+ check_slabp(cachep, slabp);
+
+ /* move slabp to correct slabp list: */
+ list_del(&slabp->list);
+ if (slabp->free == BUFCTL_END)
+ list_add(&slabp->list, &cachep->lists.slabs_full);
+ else
+ list_add(&slabp->list, &cachep->lists.slabs_partial);
+
+ list3_data(cachep)->free_objects--;
+ spin_unlock_irq(&cachep->spinlock);
+
+ objp = cache_alloc_debugcheck_after(cachep, GFP_KERNEL, objp,
+ __builtin_return_address(0));
+ return objp;
+}
+EXPORT_SYMBOL(kmem_cache_alloc_node);
+
+#endif
+
+/**
+ * kmalloc - allocate memory
+ * @size: how many bytes of memory are required.
+ * @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. Use inside interrupt handlers.
+ *
+ * Additionally, the %GFP_DMA flag may be set to indicate the memory
+ * must be suitable for DMA. This can mean different things on different
+ * platforms. For example, on i386, it means that the memory must come
+ * from the first 16MB.
+ */
+void *__kmalloc(size_t size, unsigned int __nocast flags)
+{
+ kmem_cache_t *cachep;
+
+ cachep = kmem_find_general_cachep(size, flags);
+ if (unlikely(cachep == NULL))
+ return NULL;
+ return __cache_alloc(cachep, flags);
+}
+EXPORT_SYMBOL(__kmalloc);
+
+#ifdef CONFIG_SMP
+/**
+ * __alloc_percpu - allocate one copy of the object for every present
+ * cpu in the system, zeroing them.
+ * Objects should be dereferenced using the per_cpu_ptr macro only.
+ *
+ * @size: how many bytes of memory are required.
+ * @align: the alignment, which can't be greater than SMP_CACHE_BYTES.
+ */
+void *__alloc_percpu(size_t size, size_t align)
+{
+ int i;
+ struct percpu_data *pdata = kmalloc(sizeof (*pdata), GFP_KERNEL);
+
+ if (!pdata)
+ return NULL;
+
+ for (i = 0; i < NR_CPUS; i++) {
+ if (!cpu_possible(i))
+ continue;
+ pdata->ptrs[i] = kmem_cache_alloc_node(
+ kmem_find_general_cachep(size, GFP_KERNEL),
+ cpu_to_node(i));
+
+ if (!pdata->ptrs[i])
+ goto unwind_oom;
+ memset(pdata->ptrs[i], 0, size);
+ }
+
+ /* Catch derefs w/o wrappers */
+ return (void *) (~(unsigned long) pdata);
+
+unwind_oom:
+ while (--i >= 0) {
+ if (!cpu_possible(i))
+ continue;
+ kfree(pdata->ptrs[i]);
+ }
+ kfree(pdata);
+ return NULL;
+}
+EXPORT_SYMBOL(__alloc_percpu);
+#endif
+
+/**
+ * kmem_cache_free - Deallocate an object
+ * @cachep: The cache the allocation was from.
+ * @objp: The previously allocated object.
+ *
+ * Free an object which was previously allocated from this
+ * cache.
+ */
+void kmem_cache_free(kmem_cache_t *cachep, void *objp)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __cache_free(cachep, objp);
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL(kmem_cache_free);
+
+/**
+ * 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.
+ */
+void *kcalloc(size_t n, size_t size, unsigned int __nocast flags)
+{
+ void *ret = NULL;
+
+ if (n != 0 && size > INT_MAX / n)
+ return ret;
+
+ ret = kmalloc(n * size, flags);
+ if (ret)
+ memset(ret, 0, n * size);
+ return ret;
+}
+EXPORT_SYMBOL(kcalloc);
+
+/**
+ * kfree - free previously allocated memory
+ * @objp: pointer returned by kmalloc.
+ *
+ * Don't free memory not originally allocated by kmalloc()
+ * or you will run into trouble.
+ */
+void kfree(const void *objp)
+{
+ kmem_cache_t *c;
+ unsigned long flags;
+
+ if (unlikely(!objp))
+ return;
+ local_irq_save(flags);
+ kfree_debugcheck(objp);
+ c = GET_PAGE_CACHE(virt_to_page(objp));
+ __cache_free(c, (void*)objp);
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL(kfree);
+
+#ifdef CONFIG_SMP
+/**
+ * free_percpu - free previously allocated percpu memory
+ * @objp: pointer returned by alloc_percpu.
+ *
+ * Don't free memory not originally allocated by alloc_percpu()
+ * The complemented objp is to check for that.
+ */
+void
+free_percpu(const void *objp)
+{
+ int i;
+ struct percpu_data *p = (struct percpu_data *) (~(unsigned long) objp);
+
+ for (i = 0; i < NR_CPUS; i++) {
+ if (!cpu_possible(i))
+ continue;
+ kfree(p->ptrs[i]);
+ }
+ kfree(p);
+}
+EXPORT_SYMBOL(free_percpu);
+#endif
+
+unsigned int kmem_cache_size(kmem_cache_t *cachep)
+{
+ return obj_reallen(cachep);
+}
+EXPORT_SYMBOL(kmem_cache_size);
+
+struct ccupdate_struct {
+ kmem_cache_t *cachep;
+ struct array_cache *new[NR_CPUS];
+};
+
+static void do_ccupdate_local(void *info)
+{
+ struct ccupdate_struct *new = (struct ccupdate_struct *)info;
+ struct array_cache *old;
+
+ check_irq_off();
+ old = ac_data(new->cachep);
+
+ new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()];
+ new->new[smp_processor_id()] = old;
+}
+
+
+static int do_tune_cpucache(kmem_cache_t *cachep, int limit, int batchcount,
+ int shared)
+{
+ struct ccupdate_struct new;
+ struct array_cache *new_shared;
+ int i;
+
+ memset(&new.new,0,sizeof(new.new));
+ for (i = 0; i < NR_CPUS; i++) {
+ if (cpu_online(i)) {
+ new.new[i] = alloc_arraycache(i, limit, batchcount);
+ if (!new.new[i]) {
+ for (i--; i >= 0; i--) kfree(new.new[i]);
+ return -ENOMEM;
+ }
+ } else {
+ new.new[i] = NULL;
+ }
+ }
+ new.cachep = cachep;
+
+ smp_call_function_all_cpus(do_ccupdate_local, (void *)&new);
+
+ check_irq_on();
+ spin_lock_irq(&cachep->spinlock);
+ cachep->batchcount = batchcount;
+ cachep->limit = limit;
+ cachep->free_limit = (1+num_online_cpus())*cachep->batchcount + cachep->num;
+ spin_unlock_irq(&cachep->spinlock);
+
+ for (i = 0; i < NR_CPUS; i++) {
+ struct array_cache *ccold = new.new[i];
+ if (!ccold)
+ continue;
+ spin_lock_irq(&cachep->spinlock);
+ free_block(cachep, ac_entry(ccold), ccold->avail);
+ spin_unlock_irq(&cachep->spinlock);
+ kfree(ccold);
+ }
+ new_shared = alloc_arraycache(-1, batchcount*shared, 0xbaadf00d);
+ if (new_shared) {
+ struct array_cache *old;
+
+ spin_lock_irq(&cachep->spinlock);
+ old = cachep->lists.shared;
+ cachep->lists.shared = new_shared;
+ if (old)
+ free_block(cachep, ac_entry(old), old->avail);
+ spin_unlock_irq(&cachep->spinlock);
+ kfree(old);
+ }
+
+ return 0;
+}
+
+
+static void enable_cpucache(kmem_cache_t *cachep)
+{
+ int err;
+ int limit, shared;
+
+ /* The head array serves three purposes:
+ * - create a LIFO ordering, i.e. return objects that are cache-warm
+ * - reduce the number of spinlock operations.
+ * - reduce the number of linked list operations on the slab and
+ * bufctl chains: array operations are cheaper.
+ * The numbers are guessed, we should auto-tune as described by
+ * Bonwick.
+ */
+ if (cachep->objsize > 131072)
+ limit = 1;
+ else if (cachep->objsize > PAGE_SIZE)
+ limit = 8;
+ else if (cachep->objsize > 1024)
+ limit = 24;
+ else if (cachep->objsize > 256)
+ limit = 54;
+ else
+ limit = 120;
+
+ /* Cpu bound tasks (e.g. network routing) can exhibit cpu bound
+ * allocation behaviour: Most allocs on one cpu, most free operations
+ * on another cpu. For these cases, an efficient object passing between
+ * cpus is necessary. This is provided by a shared array. The array
+ * replaces Bonwick's magazine layer.
+ * On uniprocessor, it's functionally equivalent (but less efficient)
+ * to a larger limit. Thus disabled by default.
+ */
+ shared = 0;
+#ifdef CONFIG_SMP
+ if (cachep->objsize <= PAGE_SIZE)
+ shared = 8;
+#endif
+
+#if DEBUG
+ /* With debugging enabled, large batchcount lead to excessively
+ * long periods with disabled local interrupts. Limit the
+ * batchcount
+ */
+ if (limit > 32)
+ limit = 32;
+#endif
+ err = do_tune_cpucache(cachep, limit, (limit+1)/2, shared);
+ if (err)
+ printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n",
+ cachep->name, -err);
+}
+
+static void drain_array_locked(kmem_cache_t *cachep,
+ struct array_cache *ac, int force)
+{
+ int tofree;
+
+ check_spinlock_acquired(cachep);
+ if (ac->touched && !force) {
+ ac->touched = 0;
+ } else if (ac->avail) {
+ tofree = force ? ac->avail : (ac->limit+4)/5;
+ if (tofree > ac->avail) {
+ tofree = (ac->avail+1)/2;
+ }
+ free_block(cachep, ac_entry(ac), tofree);
+ ac->avail -= tofree;
+ memmove(&ac_entry(ac)[0], &ac_entry(ac)[tofree],
+ sizeof(void*)*ac->avail);
+ }
+}
+
+/**
+ * cache_reap - Reclaim memory from caches.
+ *
+ * Called from workqueue/eventd every few seconds.
+ * Purpose:
+ * - clear the per-cpu caches for this CPU.
+ * - return freeable pages to the main free memory pool.
+ *
+ * If we cannot acquire the cache chain semaphore then just give up - we'll
+ * try again on the next iteration.
+ */
+static void cache_reap(void *unused)
+{
+ struct list_head *walk;
+
+ if (down_trylock(&cache_chain_sem)) {
+ /* Give up. Setup the next iteration. */
+ schedule_delayed_work(&__get_cpu_var(reap_work), REAPTIMEOUT_CPUC + smp_processor_id());
+ return;
+ }
+
+ list_for_each(walk, &cache_chain) {
+ kmem_cache_t *searchp;
+ struct list_head* p;
+ int tofree;
+ struct slab *slabp;
+
+ searchp = list_entry(walk, kmem_cache_t, next);
+
+ if (searchp->flags & SLAB_NO_REAP)
+ goto next;
+
+ check_irq_on();
+
+ spin_lock_irq(&searchp->spinlock);
+
+ drain_array_locked(searchp, ac_data(searchp), 0);
+
+ if(time_after(searchp->lists.next_reap, jiffies))
+ goto next_unlock;
+
+ searchp->lists.next_reap = jiffies + REAPTIMEOUT_LIST3;
+
+ if (searchp->lists.shared)
+ drain_array_locked(searchp, searchp->lists.shared, 0);
+
+ if (searchp->lists.free_touched) {
+ searchp->lists.free_touched = 0;
+ goto next_unlock;
+ }
+
+ tofree = (searchp->free_limit+5*searchp->num-1)/(5*searchp->num);
+ do {
+ p = list3_data(searchp)->slabs_free.next;
+ if (p == &(list3_data(searchp)->slabs_free))
+ break;
+
+ slabp = list_entry(p, struct slab, list);
+ BUG_ON(slabp->inuse);
+ list_del(&slabp->list);
+ STATS_INC_REAPED(searchp);
+
+ /* Safe to drop the lock. The slab is no longer
+ * linked to the cache.
+ * searchp cannot disappear, we hold
+ * cache_chain_lock
+ */
+ searchp->lists.free_objects -= searchp->num;
+ spin_unlock_irq(&searchp->spinlock);
+ slab_destroy(searchp, slabp);
+ spin_lock_irq(&searchp->spinlock);
+ } while(--tofree > 0);
+next_unlock:
+ spin_unlock_irq(&searchp->spinlock);
+next:
+ cond_resched();
+ }
+ check_irq_on();
+ up(&cache_chain_sem);
+ /* Setup the next iteration */
+ schedule_delayed_work(&__get_cpu_var(reap_work), REAPTIMEOUT_CPUC + smp_processor_id());
+}
+
+#ifdef CONFIG_PROC_FS
+
+static void *s_start(struct seq_file *m, loff_t *pos)
+{
+ loff_t n = *pos;
+ struct list_head *p;
+
+ down(&cache_chain_sem);
+ if (!n) {
+ /*
+ * Output format version, so at least we can change it
+ * without _too_ many complaints.
+ */
+#if STATS
+ seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
+#else
+ seq_puts(m, "slabinfo - version: 2.1\n");
+#endif
+ seq_puts(m, "# name <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab>");
+ seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
+ seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
+#if STATS
+ seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped>"
+ " <error> <maxfreeable> <freelimit> <nodeallocs>");
+ seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
+#endif
+ seq_putc(m, '\n');
+ }
+ p = cache_chain.next;
+ while (n--) {
+ p = p->next;
+ if (p == &cache_chain)
+ return NULL;
+ }
+ return list_entry(p, kmem_cache_t, next);
+}
+
+static void *s_next(struct seq_file *m, void *p, loff_t *pos)
+{
+ kmem_cache_t *cachep = p;
+ ++*pos;
+ return cachep->next.next == &cache_chain ? NULL
+ : list_entry(cachep->next.next, kmem_cache_t, next);
+}
+
+static void s_stop(struct seq_file *m, void *p)
+{
+ up(&cache_chain_sem);
+}
+
+static int s_show(struct seq_file *m, void *p)
+{
+ kmem_cache_t *cachep = p;
+ struct list_head *q;
+ struct slab *slabp;
+ unsigned long active_objs;
+ unsigned long num_objs;
+ unsigned long active_slabs = 0;
+ unsigned long num_slabs;
+ const char *name;
+ char *error = NULL;
+
+ check_irq_on();
+ spin_lock_irq(&cachep->spinlock);
+ active_objs = 0;
+ num_slabs = 0;
+ list_for_each(q,&cachep->lists.slabs_full) {
+ slabp = list_entry(q, struct slab, list);
+ if (slabp->inuse != cachep->num && !error)
+ error = "slabs_full accounting error";
+ active_objs += cachep->num;
+ active_slabs++;
+ }
+ list_for_each(q,&cachep->lists.slabs_partial) {
+ slabp = list_entry(q, struct slab, list);
+ if (slabp->inuse == cachep->num && !error)
+ error = "slabs_partial inuse accounting error";
+ if (!slabp->inuse && !error)
+ error = "slabs_partial/inuse accounting error";
+ active_objs += slabp->inuse;
+ active_slabs++;
+ }
+ list_for_each(q,&cachep->lists.slabs_free) {
+ slabp = list_entry(q, struct slab, list);
+ if (slabp->inuse && !error)
+ error = "slabs_free/inuse accounting error";
+ num_slabs++;
+ }
+ num_slabs+=active_slabs;
+ num_objs = num_slabs*cachep->num;
+ if (num_objs - active_objs != cachep->lists.free_objects && !error)
+ error = "free_objects accounting error";
+
+ name = cachep->name;
+ if (error)
+ printk(KERN_ERR "slab: cache %s error: %s\n", name, error);
+
+ seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
+ name, active_objs, num_objs, cachep->objsize,
+ cachep->num, (1<<cachep->gfporder));
+ seq_printf(m, " : tunables %4u %4u %4u",
+ cachep->limit, cachep->batchcount,
+ cachep->lists.shared->limit/cachep->batchcount);
+ seq_printf(m, " : slabdata %6lu %6lu %6u",
+ active_slabs, num_slabs, cachep->lists.shared->avail);
+#if STATS
+ { /* list3 stats */
+ unsigned long high = cachep->high_mark;
+ unsigned long allocs = cachep->num_allocations;
+ unsigned long grown = cachep->grown;
+ unsigned long reaped = cachep->reaped;
+ unsigned long errors = cachep->errors;
+ unsigned long max_freeable = cachep->max_freeable;
+ unsigned long free_limit = cachep->free_limit;
+ unsigned long node_allocs = cachep->node_allocs;
+
+ seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu %4lu %4lu %4lu %4lu",
+ allocs, high, grown, reaped, errors,
+ max_freeable, free_limit, node_allocs);
+ }
+ /* cpu stats */
+ {
+ unsigned long allochit = atomic_read(&cachep->allochit);
+ unsigned long allocmiss = atomic_read(&cachep->allocmiss);
+ unsigned long freehit = atomic_read(&cachep->freehit);
+ unsigned long freemiss = atomic_read(&cachep->freemiss);
+
+ seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu",
+ allochit, allocmiss, freehit, freemiss);
+ }
+#endif
+ seq_putc(m, '\n');
+ spin_unlock_irq(&cachep->spinlock);
+ return 0;
+}
+
+/*
+ * slabinfo_op - iterator that generates /proc/slabinfo
+ *
+ * Output layout:
+ * cache-name
+ * num-active-objs
+ * total-objs
+ * object size
+ * num-active-slabs
+ * total-slabs
+ * num-pages-per-slab
+ * + further values on SMP and with statistics enabled
+ */
+
+struct seq_operations slabinfo_op = {
+ .start = s_start,
+ .next = s_next,
+ .stop = s_stop,
+ .show = s_show,
+};
+
+#define MAX_SLABINFO_WRITE 128
+/**
+ * slabinfo_write - Tuning for the slab allocator
+ * @file: unused
+ * @buffer: user buffer
+ * @count: data length
+ * @ppos: unused
+ */
+ssize_t slabinfo_write(struct file *file, const char __user *buffer,
+ size_t count, loff_t *ppos)
+{
+ char kbuf[MAX_SLABINFO_WRITE+1], *tmp;
+ int limit, batchcount, shared, res;
+ struct list_head *p;
+
+ if (count > MAX_SLABINFO_WRITE)
+ return -EINVAL;
+ if (copy_from_user(&kbuf, buffer, count))
+ return -EFAULT;
+ kbuf[MAX_SLABINFO_WRITE] = '\0';
+
+ tmp = strchr(kbuf, ' ');
+ if (!tmp)
+ return -EINVAL;
+ *tmp = '\0';
+ tmp++;
+ if (sscanf(tmp, " %d %d %d", &limit, &batchcount, &shared) != 3)
+ return -EINVAL;
+
+ /* Find the cache in the chain of caches. */
+ down(&cache_chain_sem);
+ res = -EINVAL;
+ list_for_each(p,&cache_chain) {
+ kmem_cache_t *cachep = list_entry(p, kmem_cache_t, next);
+
+ if (!strcmp(cachep->name, kbuf)) {
+ if (limit < 1 ||
+ batchcount < 1 ||
+ batchcount > limit ||
+ shared < 0) {
+ res = -EINVAL;
+ } else {
+ res = do_tune_cpucache(cachep, limit, batchcount, shared);
+ }
+ break;
+ }
+ }
+ up(&cache_chain_sem);
+ if (res >= 0)
+ res = count;
+ return res;
+}
+#endif
+
+unsigned int ksize(const void *objp)
+{
+ kmem_cache_t *c;
+ unsigned long flags;
+ unsigned int size = 0;
+
+ if (likely(objp != NULL)) {
+ local_irq_save(flags);
+ c = GET_PAGE_CACHE(virt_to_page(objp));
+ size = kmem_cache_size(c);
+ local_irq_restore(flags);
+ }
+
+ return size;
+}