litmus-rt.git - The LITMUS^RT kernel.

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author	Bruce Allan <bruce.w.allan@intel.com>	2011-05-13 03:19:42 -0400
committer	Jeff Kirsher <jeffrey.t.kirsher@intel.com>	2011-06-09 23:31:24 -0400
commit	d9b24135b972ccdd5f5174fba06c730e895e6daf (patch)
tree	ae5176a5b75cb8790d6411b5eb269edaaf31aec2 /drivers/net/e1000e/es2lan.c
parent	e357964ee66723d0ced63ac1dbd1db4a6a1d417e (diff)

e1000e: disable far-end loopback mode on ESB2

The ESB2 LAN includes a debug feature that enables far-end loopback (FELB) of the SerDes/Kumeran interface. This feature is activated when receiving a sequence of symbols that includes a reserved codeword. On a perfect link, FELB would never be activated. In the presence of bit errors, there is a very small, but non-zero, probability of FELB being activated. If the FELB is activated, the SerDes link becomes non-functional and must be reset. It could also corrupt the switching tables in the switch since the ESB2 is transmitting packets with a different source MAC address. This patch disables the FELB feature. Signed-off-by: Bruce Allan <bruce.w.allan@intel.com> Tested-by: Aaron Brown <aaron.f.brown@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Diffstat (limited to 'drivers/net/e1000e/es2lan.c')

-rw-r--r--

drivers/net/e1000e/es2lan.c

1 files changed, 8 insertions, 0 deletions

         struct e1000_mac_info *mac = &hw->mac;
         u32 reg_data;
         s32 ret_val;
+        u16 kum_reg_data;
         u16 i;
         e1000_initialize_hw_bits_80003es2lan(hw);
         /* Setup link and flow control */
         ret_val = e1000e_setup_link(hw);
+        /* Disable IBIST slave mode (far-end loopback) */
+        e1000_read_kmrn_reg_80003es2lan(hw, E1000_KMRNCTRLSTA_INBAND_PARAM,
+                                        &kum_reg_data);
+        kum_reg_data |= E1000_KMRNCTRLSTA_IBIST_DISABLE;
+        e1000_write_kmrn_reg_80003es2lan(hw, E1000_KMRNCTRLSTA_INBAND_PARAM,
+                                         kum_reg_data);
         /* Set the transmit descriptor write-back policy */
         reg_data = er32(TXDCTL(0));
         reg_data = (reg_data & ~E1000_TXDCTL_WTHRESH) |

/* * 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 initializations 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 struct kmem_cache 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 mutex 'cache_chain_mutex'. * 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. * * 15 March 2005. NUMA slab allocator. * Shai Fultheim <shai@scalex86.org>. * Shobhit Dayal <shobhit@calsoftinc.com> * Alok N Kataria <alokk@calsoftinc.com> * Christoph Lameter <christoph@lameter.com> * * Modified the slab allocator to be node aware on NUMA systems. * Each node has its own list of partial, free and full slabs. * All object allocations for a node occur from node specific slab lists. */ #include <linux/slab.h> #include <linux/mm.h> #include <linux/poison.h> #include <linux/swap.h> #include <linux/cache.h> #include <linux/interrupt.h> #include <linux/init.h> #include <linux/compiler.h> #include <linux/cpuset.h> #include <linux/proc_fs.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 <linux/string.h> #include <linux/uaccess.h> #include <linux/nodemask.h> #include <linux/mempolicy.h> #include <linux/mutex.h> #include <linux/fault-inject.h> #include <linux/rtmutex.h> #include <linux/reciprocal_div.h> #include <linux/debugobjects.h> #include <asm/cacheflush.h> #include <asm/tlbflush.h> #include <asm/page.h> /* * DEBUG - 1 for kmem_cache_create() to honour; 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 *) #define REDZONE_ALIGN max(BYTES_PER_WORD, __alignof__(unsigned long long)) #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 the alignment of a 64-bit integer. * ARCH_KMALLOC_MINALIGN allows that. * Note that increasing this value may disable some debug features. */ #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long) #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_RED_ZONE | \ SLAB_POISON | SLAB_HWCACHE_ALIGN | \ SLAB_CACHE_DMA | \ SLAB_STORE_USER | \ SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \ SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD | \ SLAB_DEBUG_OBJECTS) #else # define CREATE_MASK (SLAB_HWCACHE_ALIGN | \ SLAB_CACHE_DMA | \ SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \ SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD | \ SLAB_DEBUG_OBJECTS) #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. */ typedef unsigned int kmem_bufctl_t; #define BUFCTL_END (((kmem_bufctl_t)(~0U))-0) #define BUFCTL_FREE (((kmem_bufctl_t)(~0U))-1) #define BUFCTL_ACTIVE (((kmem_bufctl_t)(~0U))-2) #define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-3) /* * 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; unsigned short nodeid; }; /* * 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; struct kmem_cache *cachep; void *addr; }; /* * struct array_cache * * 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; spinlock_t lock; void *entry[]; /* * Must have this definition in here for the proper * alignment of array_cache. Also simplifies accessing * the entries. */ }; /* * 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 for all objects. */ 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; unsigned int free_limit; unsigned int colour_next; /* Per-node cache coloring */ spinlock_t list_lock; struct array_cache *shared; /* shared per node */ struct array_cache **alien; /* on other nodes */ unsigned long next_reap; /* updated without locking */ int free_touched; /* updated without locking */ }; /* * Need this for bootstrapping a per node allocator. */ #define NUM_INIT_LISTS (3 * MAX_NUMNODES) struct kmem_list3 __initdata initkmem_list3[NUM_INIT_LISTS]; #define CACHE_CACHE 0 #define SIZE_AC MAX_NUMNODES #define SIZE_L3 (2 * MAX_NUMNODES) static int drain_freelist(struct kmem_cache *cache, struct kmem_list3 *l3, int tofree); static void free_block(struct kmem_cache *cachep, void **objpp, int len, int node); static int enable_cpucache(struct kmem_cache *cachep); static void cache_reap(struct work_struct *unused); /* * This function must be completely optimized away if a constant is passed to * it. Mostly the same as what is in linux/slab.h except it returns an index. */ static __always_inline int index_of(const size_t size) { extern void __bad_size(void); if (__builtin_constant_p(size)) { int i = 0; #define CACHE(x) \ if (size <=x) \ return i; \ else \ i++; #include <linux/kmalloc_sizes.h> #undef CACHE __bad_size(); } else __bad_size(); return 0; } static int slab_early_init = 1; #define INDEX_AC index_of(sizeof(struct arraycache_init)) #define INDEX_L3 index_of(sizeof(struct kmem_list3)) static void kmem_list3_init(struct kmem_list3 *parent) { INIT_LIST_HEAD(&parent->slabs_full); INIT_LIST_HEAD(&parent->slabs_partial); INIT_LIST_HEAD(&parent->slabs_free); parent->shared = NULL; parent->alien = NULL; parent->colour_next = 0; spin_lock_init(&parent->list_lock); parent->free_objects = 0; parent->free_touched = 0; } #define MAKE_LIST(cachep, listp, slab, nodeid) \ do { \ INIT_LIST_HEAD(listp); \ list_splice(&(cachep->nodelists[nodeid]->slab), listp); \ } while (0) #define MAKE_ALL_LISTS(cachep, ptr, nodeid) \ do { \ MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \ MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \ MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \ } while (0) /* * struct kmem_cache * * manages a cache. */ struct kmem_cache { /* 1) per-cpu data, touched during every alloc/free */ struct array_cache *array[NR_CPUS]; /* 2) Cache tunables. Protected by cache_chain_mutex */ unsigned int batchcount; unsigned int limit; unsigned int shared; unsigned int buffer_size; u32 reciprocal_buffer_size; /* 3) touched by every alloc & free from the backend */ unsigned int flags; /* constant flags */ unsigned int num; /* # of objs per slab */ /* 4) cache_grow/shrink */ /* order of pgs per slab (2^n) */ unsigned int gfporder; /* force GFP flags, e.g. GFP_DMA */ gfp_t gfpflags; size_t colour; /* cache colouring range */ unsigned int colour_off; /* colour offset */ struct kmem_cache *slabp_cache; unsigned int slab_size; unsigned int dflags; /* dynamic flags */ /* constructor func */ void (*ctor)(void *obj); /* 5) cache creation/removal */ const char *name; struct list_head next; /* 6) 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; unsigned long node_frees; unsigned long node_overflow; atomic_t allochit; atomic_t allocmiss; atomic_t freehit; atomic_t freemiss; #endif #if DEBUG /* * If debugging is enabled, then the allocator can add additional * fields and/or padding to every object. buffer_size contains the total * object size including these internal fields, the following two * variables contain the offset to the user object and its size. */ int obj_offset; int obj_size; #endif /* * We put nodelists[] at the end of kmem_cache, because we want to size * this array to nr_node_ids slots instead of MAX_NUMNODES * (see kmem_cache_init()) * We still use [MAX_NUMNODES] and not [1] or [0] because cache_cache * is statically defined, so we reserve the max number of nodes. */ struct kmem_list3 *nodelists[MAX_NUMNODES]; /* * Do not add fields after nodelists[] */ }; #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. * * OTOH 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_ADD_REAPED(x,y) ((x)->reaped += (y)) #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_INC_NODEFREES(x) ((x)->node_frees++) #define STATS_INC_ACOVERFLOW(x) ((x)->node_overflow++) #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_ADD_REAPED(x,y) 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_INC_NODEFREES(x) do { } while (0) #define STATS_INC_ACOVERFLOW(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 /* * memory layout of objects: * 0 : objp * 0 .. cachep->obj_offset - 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->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1: * redzone word. * cachep->obj_offset: The real object. * cachep->buffer_size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long] * cachep->buffer_size - 1* BYTES_PER_WORD: last caller address * [BYTES_PER_WORD long] */ static int obj_offset(struct kmem_cache *cachep) { return cachep->obj_offset; } static int obj_size(struct kmem_cache *cachep) { return cachep->obj_size; } static unsigned long long *dbg_redzone1(struct kmem_cache *cachep, void *objp) { BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); return (unsigned long long*) (objp + obj_offset(cachep) - sizeof(unsigned long long)); } static unsigned long long *dbg_redzone2(struct kmem_cache *cachep, void *objp) { BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); if (cachep->flags & SLAB_STORE_USER) return (unsigned long long *)(objp + cachep->buffer_size - sizeof(unsigned long long) - REDZONE_ALIGN); return (unsigned long long *) (objp + cachep->buffer_size - sizeof(unsigned long long)); } static void **dbg_userword(struct kmem_cache *cachep, void *objp) { BUG_ON(!(cachep->flags & SLAB_STORE_USER)); return (void **)(objp + cachep->buffer_size - BYTES_PER_WORD); } #else #define obj_offset(x) 0 #define obj_size(cachep) (cachep->buffer_size) #define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long long *)NULL;}) #define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long long *)NULL;}) #define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;}) #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; /* * Functions for storing/retrieving the cachep and or slab from the page * allocator. 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. */ static inline void page_set_cache(struct page *page, struct kmem_cache *cache) { page->lru.next = (struct list_head *)cache; } static inline struct kmem_cache *page_get_cache(struct page *page) { page = compound_head(page); BUG_ON(!PageSlab(page)); return (struct kmem_cache *)page->lru.next; } static inline void page_set_slab(struct page *page, struct slab *slab) { page->lru.prev = (struct list_head *)slab; } static inline struct slab *page_get_slab(struct page *page) { BUG_ON(!PageSlab(page)); return (struct slab *)page->lru.prev; } static inline struct kmem_cache *virt_to_cache(const void *obj) { struct page *page = virt_to_head_page(obj); return page_get_cache(page); } static inline struct slab *virt_to_slab(const void *obj) { struct page *page = virt_to_head_page(obj); return page_get_slab(page); } static inline void *index_to_obj(struct kmem_cache *cache, struct slab *slab, unsigned int idx) { return slab->s_mem + cache->buffer_size * idx; } /* * We want to avoid an expensive divide : (offset / cache->buffer_size) * Using the fact that buffer_size is a constant for a particular cache, * we can replace (offset / cache->buffer_size) by * reciprocal_divide(offset, cache->reciprocal_buffer_size) */ static inline unsigned int obj_to_index(const struct kmem_cache *cache, const struct slab *slab, void *obj) { u32 offset = (obj - slab->s_mem); return reciprocal_divide(offset, cache->reciprocal_buffer_size); } /* * 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 struct kmem_cache cache_cache = { .batchcount = 1, .limit = BOOT_CPUCACHE_ENTRIES, .shared = 1, .buffer_size = sizeof(struct kmem_cache), .name = "kmem_cache", }; #define BAD_ALIEN_MAGIC 0x01020304ul #ifdef CONFIG_LOCKDEP /* * Slab sometimes uses the kmalloc slabs to store the slab headers * for other slabs "off slab". * The locking for this is tricky in that it nests within the locks * of all other slabs in a few places; to deal with this special * locking we put on-slab caches into a separate lock-class. * * We set lock class for alien array caches which are up during init. * The lock annotation will be lost if all cpus of a node goes down and * then comes back up during hotplug */ static struct lock_class_key on_slab_l3_key; static struct lock_class_key on_slab_alc_key; static inline void init_lock_keys(void) { int q; struct cache_sizes *s = malloc_sizes; while (s->cs_size != ULONG_MAX) { for_each_node(q) { struct array_cache **alc; int r; struct kmem_list3 *l3 = s->cs_cachep->nodelists[q]; if (!l3 || OFF_SLAB(s->cs_cachep)) continue; lockdep_set_class(&l3->list_lock, &on_slab_l3_key); alc = l3->alien; /* * FIXME: This check for BAD_ALIEN_MAGIC * should go away when common slab code is taught to * work even without alien caches. * Currently, non NUMA code returns BAD_ALIEN_MAGIC * for alloc_alien_cache, */ if (!alc || (unsigned long)alc == BAD_ALIEN_MAGIC) continue; for_each_node(r) { if (alc[r]) lockdep_set_class(&alc[r]->lock, &on_slab_alc_key); } } s++; } } #else static inline void init_lock_keys(void) { } #endif /* * Guard access to the cache-chain. */ static DEFINE_MUTEX(cache_chain_mutex); static struct list_head cache_chain; /* * chicken and egg problem: delay the per-cpu array allocation * until the general caches are up. */ static enum { NONE, PARTIAL_AC, PARTIAL_L3, FULL } g_cpucache_up; /* * used by boot code to determine if it can use slab based allocator */ int slab_is_available(void) { return g_cpucache_up == FULL; } static DEFINE_PER_CPU(struct delayed_work, reap_work); static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep) { return cachep->array[smp_processor_id()]; } static inline struct kmem_cache *__find_general_cachep(size_t size, gfp_t 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(malloc_sizes[INDEX_AC].cs_cachep == NULL); #endif if (!size) return ZERO_SIZE_PTR; while (size > csizep->cs_size) csizep++; /* * Really subtle: The last entry with cs->cs_size==ULONG_MAX * has cs_{dma,}cachep==NULL. Thus no special case * for large kmalloc calls required. */ #ifdef CONFIG_ZONE_DMA if (unlikely(gfpflags & GFP_DMA)) return csizep->cs_dmacachep; #endif return csizep->cs_cachep; } static struct kmem_cache *kmem_find_general_cachep(size_t size, gfp_t gfpflags) { return __find_general_cachep(size, gfpflags); } static size_t slab_mgmt_size(size_t nr_objs, size_t align) { return ALIGN(sizeof(struct slab)+nr_objs*sizeof(kmem_bufctl_t), align); } /* * Calculate the number of objects and left-over bytes for a given buffer size. */ static void cache_estimate(unsigned long gfporder, size_t buffer_size, size_t align, int flags, size_t *left_over, unsigned int *num) { int nr_objs; size_t mgmt_size; size_t slab_size = PAGE_SIZE << gfporder; /* * The slab management structure can be either off the slab or * on it. For the latter case, the memory allocated for a * slab is used for: * * - The struct slab * - One kmem_bufctl_t for each object * - Padding to respect alignment of @align * - @buffer_size bytes for each object * * If the slab management structure is off the slab, then the * alignment will already be calculated into the size. Because * the slabs are all pages aligned, the objects will be at the * correct alignment when allocated. */ if (flags & CFLGS_OFF_SLAB) { mgmt_size = 0; nr_objs = slab_size / buffer_size; if (nr_objs > SLAB_LIMIT) nr_objs = SLAB_LIMIT; } else { /* * Ignore padding for the initial guess. The padding * is at most @align-1 bytes, and @buffer_size is at * least @align. In the worst case, this result will * be one greater than the number of objects that fit * into the memory allocation when taking the padding * into account. */ nr_objs = (slab_size - sizeof(struct slab)) / (buffer_size + sizeof(kmem_bufctl_t)); /* * This calculated number will be either the right * amount, or one greater than what we want. */ if (slab_mgmt_size(nr_objs, align) + nr_objs*buffer_size > slab_size) nr_objs--; if (nr_objs > SLAB_LIMIT) nr_objs = SLAB_LIMIT; mgmt_size = slab_mgmt_size(nr_objs, align); } *num = nr_objs; *left_over = slab_size - nr_objs*buffer_size - mgmt_size; } #define slab_error(cachep, msg) __slab_error(__func__, cachep, msg) static void __slab_error(const char *function, struct kmem_cache *cachep, char *msg) { printk(KERN_ERR "slab error in %s(): cache `%s': %s\n", function, cachep->name, msg); dump_stack(); } /* * By default on NUMA we use alien caches to stage the freeing of * objects allocated from other nodes. This causes massive memory * inefficiencies when using fake NUMA setup to split memory into a * large number of small nodes, so it can be disabled on the command * line */ static int use_alien_caches __read_mostly = 1; static int numa_platform __read_mostly = 1; static int __init noaliencache_setup(char *s) { use_alien_caches = 0; return 1; } __setup("noaliencache", noaliencache_setup); #ifdef CONFIG_NUMA /* * Special reaping functions for NUMA systems called from cache_reap(). * These take care of doing round robin flushing of alien caches (containing * objects freed on different nodes from which they were allocated) and the * flushing of remote pcps by calling drain_node_pages. */ static DEFINE_PER_CPU(unsigned long, reap_node); static void init_reap_node(int cpu) { int node; node = next_node(cpu_to_node(cpu), node_online_map); if (node == MAX_NUMNODES) node = first_node(node_online_map); per_cpu(reap_node, cpu) = node; } static void next_reap_node(void) { int node = __get_cpu_var(reap_node); node = next_node(node, node_online_map); if (unlikely(node >= MAX_NUMNODES)) node = first_node(node_online_map); __get_cpu_var(reap_node) = node; } #else #define init_reap_node(cpu) do { } while (0) #define next_reap_node(void) do { } while (0) #endif /* * 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 __cpuinit start_cpu_timer(int cpu) { struct delayed_work *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->work.func == NULL) { init_reap_node(cpu); INIT_DELAYED_WORK(reap_work, cache_reap); schedule_delayed_work_on(cpu, reap_work, __round_jiffies_relative(HZ, cpu)); } } static struct array_cache *alloc_arraycache(int node, int entries, int batchcount) { int memsize = sizeof(void *) * entries + sizeof(struct array_cache); struct array_cache *nc = NULL; nc = kmalloc_node(memsize, GFP_KERNEL, node); if (nc) { nc->avail = 0; nc->limit = entries; nc->batchcount = batchcount; nc->touched = 0; spin_lock_init(&nc->lock); } return nc; } /* * Transfer objects in one arraycache to another. * Locking must be handled by the caller. * * Return the number of entries transferred. */ static int transfer_objects(struct array_cache *to, struct array_cache *from, unsigned int max) { /* Figure out how many entries to transfer */ int nr = min(min(from->avail, max), to->limit - to->avail); if (!nr) return 0; memcpy(to->entry + to->avail, from->entry + from->avail -nr, sizeof(void *) *nr); from->avail -= nr; to->avail += nr; to->touched = 1; return nr; } #ifndef CONFIG_NUMA #define drain_alien_cache(cachep, alien) do { } while (0) #define reap_alien(cachep, l3) do { } while (0) static inline struct array_cache **alloc_alien_cache(int node, int limit) { return (struct array_cache **)BAD_ALIEN_MAGIC; } static inline void free_alien_cache(struct array_cache **ac_ptr) { } static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) { return 0; } static inline void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags) { return NULL; } static inline void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid) { return NULL; } #else /* CONFIG_NUMA */ static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int); static void *alternate_node_alloc(struct kmem_cache *, gfp_t); static struct array_cache **alloc_alien_cache(int node, int limit) { struct array_cache **ac_ptr; int memsize = sizeof(void *) * nr_node_ids; int i; if (limit > 1) limit = 12; ac_ptr = kmalloc_node(memsize, GFP_KERNEL, node); if (ac_ptr) { for_each_node(i) { if (i == node || !node_online(i)) { ac_ptr[i] = NULL; continue; } ac_ptr[i] = alloc_arraycache(node, limit, 0xbaadf00d); if (!ac_ptr[i]) { for (i--; i >= 0; i--) kfree(ac_ptr[i]); kfree(ac_ptr); return NULL; } } } return ac_ptr; } static void free_alien_cache(struct array_cache **ac_ptr) { int i; if (!ac_ptr) return; for_each_node(i) kfree(ac_ptr[i]); kfree(ac_ptr); } static void __drain_alien_cache(struct kmem_cache *cachep, struct array_cache *ac, int node) { struct kmem_list3 *rl3 = cachep->nodelists[node]; if (ac->avail) { spin_lock(&rl3->list_lock); /* * Stuff objects into the remote nodes shared array first. * That way we could avoid the overhead of putting the objects * into the free lists and getting them back later. */ if (rl3->shared) transfer_objects(rl3->shared, ac, ac->limit); free_block(cachep, ac->entry, ac->avail, node); ac->avail = 0; spin_unlock(&rl3->list_lock); } } /* * Called from cache_reap() to regularly drain alien caches round robin. */ static void reap_alien(struct kmem_cache *cachep, struct kmem_list3 *l3) { int node = __get_cpu_var(reap_node); if (l3->alien) { struct array_cache *ac = l3->alien[node]; if (ac && ac->avail && spin_trylock_irq(&ac->lock)) { __drain_alien_cache(cachep, ac, node); spin_unlock_irq(&ac->lock); } } } static void drain_alien_cache(struct kmem_cache *cachep, struct array_cache **alien) { int i = 0; struct array_cache *ac; unsigned long flags; for_each_online_node(i) { ac = alien[i]; if (ac) { spin_lock_irqsave(&ac->lock, flags); __drain_alien_cache(cachep, ac, i); spin_unlock_irqrestore(&ac->lock, flags); } } } static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) { struct slab *slabp = virt_to_slab(objp); int nodeid = slabp->nodeid; struct kmem_list3 *l3; struct array_cache *alien = NULL; int node; node = numa_node_id(); /* * Make sure we are not freeing a object from another node to the array * cache on this cpu. */ if (likely(slabp->nodeid == node)) return 0; l3 = cachep->nodelists[node]; STATS_INC_NODEFREES(cachep); if (l3->alien && l3->alien[nodeid]) { alien = l3->alien[nodeid]; spin_lock(&alien->lock); if (unlikely(alien->avail == alien->limit)) { STATS_INC_ACOVERFLOW(cachep); __drain_alien_cache(cachep, alien, nodeid); } alien->entry[alien->avail++] = objp; spin_unlock(&alien->lock); } else { spin_lock(&(cachep->nodelists[nodeid])->list_lock); free_block(cachep, &objp, 1, nodeid); spin_unlock(&(cachep->nodelists[nodeid])->list_lock); } return 1; } #endif static void __cpuinit cpuup_canceled(long cpu) { struct kmem_cache *cachep; struct kmem_list3 *l3 = NULL; int node = cpu_to_node(cpu); node_to_cpumask_ptr(mask, node); list_for_each_entry(cachep, &cache_chain, next) { struct array_cache *nc; struct array_cache *shared; struct array_cache **alien; /* cpu is dead; no one can alloc from it. */ nc = cachep->array[cpu]; cachep->array[cpu] = NULL; l3 = cachep->nodelists[node]; if (!l3) goto free_array_cache; spin_lock_irq(&l3->list_lock); /* Free limit for this kmem_list3 */ l3->free_limit -= cachep->batchcount; if (nc) free_block(cachep, nc->entry, nc->avail, node); if (!cpus_empty(*mask)) { spin_unlock_irq(&l3->list_lock); goto free_array_cache; } shared = l3->shared; if (shared) { free_block(cachep, shared->entry, shared->avail, node); l3->shared = NULL; } alien = l3->alien; l3->alien = NULL; spin_unlock_irq(&l3->list_lock); kfree(shared); if (alien) { drain_alien_cache(cachep, alien); free_alien_cache(alien); } free_array_cache: kfree(nc); } /* * In the previous loop, all the objects were freed to * the respective cache's slabs, now we can go ahead and * shrink each nodelist to its limit. */ list_for_each_entry(cachep, &cache_chain, next) { l3 = cachep->nodelists[node]; if (!l3) continue; drain_freelist(cachep, l3, l3->free_objects); } } static int __cpuinit cpuup_prepare(long cpu) { struct kmem_cache *cachep; struct kmem_list3 *l3 = NULL; int node = cpu_to_node(cpu); const int memsize = sizeof(struct kmem_list3); /* * We need to do this right in the beginning since * alloc_arraycache's are going to use this list. * kmalloc_node allows us to add the slab to the right * kmem_list3 and not this cpu's kmem_list3 */ list_for_each_entry(cachep, &cache_chain, next) { /* * Set up the size64 kmemlist for cpu before we can * begin anything. Make sure some other cpu on this * node has not already allocated this */ if (!cachep->nodelists[node]) { l3 = kmalloc_node(memsize, GFP_KERNEL, node); if (!l3) goto bad; kmem_list3_init(l3); l3->next_reap = jiffies + REAPTIMEOUT_LIST3 + ((unsigned long)cachep) % REAPTIMEOUT_LIST3; /* * The l3s don't come and go as CPUs come and * go. cache_chain_mutex is sufficient * protection here. */ cachep->nodelists[node] = l3; } spin_lock_irq(&cachep->nodelists[node]->list_lock); cachep->nodelists[node]->free_limit = (1 + nr_cpus_node(node)) * cachep->batchcount + cachep->num; spin_unlock_irq(&cachep->nodelists[node]->list_lock); } /* * Now we can go ahead with allocating the shared arrays and * array caches */ list_for_each_entry(cachep, &cache_chain, next) { struct array_cache *nc; struct array_cache *shared = NULL; struct array_cache **alien = NULL; nc = alloc_arraycache(node, cachep->limit, cachep->batchcount); if (!nc) goto bad; if (cachep->shared) { shared = alloc_arraycache(node, cachep->shared * cachep->batchcount, 0xbaadf00d); if (!shared) { kfree(nc); goto bad; } } if (use_alien_caches) { alien = alloc_alien_cache(node, cachep->limit); if (!alien) { kfree(shared); kfree(nc); goto bad; } } cachep->array[cpu] = nc; l3 = cachep->nodelists[node]; BUG_ON(!l3); spin_lock_irq(&l3->list_lock); if (!l3->shared) { /* * We are serialised from CPU_DEAD or * CPU_UP_CANCELLED by the cpucontrol lock */ l3->shared = shared; shared = NULL; } #ifdef CONFIG_NUMA if (!l3->alien) { l3->alien = alien; alien = NULL; } #endif spin_unlock_irq(&l3->list_lock); kfree(shared); free_alien_cache(alien); } return 0; bad: cpuup_canceled(cpu); return -ENOMEM; } static int __cpuinit cpuup_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) { long cpu = (long)hcpu; int err = 0; switch (action) { case CPU_UP_PREPARE: case CPU_UP_PREPARE_FROZEN: mutex_lock(&cache_chain_mutex); err = cpuup_prepare(cpu); mutex_unlock(&cache_chain_mutex); break; case CPU_ONLINE: case CPU_ONLINE_FROZEN: start_cpu_timer(cpu); break; #ifdef CONFIG_HOTPLUG_CPU case CPU_DOWN_PREPARE: case CPU_DOWN_PREPARE_FROZEN: /* * Shutdown cache reaper. Note that the cache_chain_mutex is * held so that if cache_reap() is invoked it cannot do * anything expensive but will only modify reap_work * and reschedule the timer. */ cancel_rearming_delayed_work(&per_cpu(reap_work, cpu)); /* Now the cache_reaper is guaranteed to be not running. */ per_cpu(reap_work, cpu).work.func = NULL; break; case CPU_DOWN_FAILED: case CPU_DOWN_FAILED_FROZEN: start_cpu_timer(cpu); break; case CPU_DEAD: case CPU_DEAD_FROZEN: /* * Even if all the cpus of a node are down, we don't free the * kmem_list3 of any cache. This to avoid a race between * cpu_down, and a kmalloc allocation from another cpu for * memory from the node of the cpu going down. The list3 * structure is usually allocated from kmem_cache_create() and * gets destroyed at kmem_cache_destroy(). */ /* fall through */ #endif case CPU_UP_CANCELED: case CPU_UP_CANCELED_FROZEN: mutex_lock(&cache_chain_mutex); cpuup_canceled(cpu); mutex_unlock(&cache_chain_mutex); break; } return err ? NOTIFY_BAD : NOTIFY_OK; } static struct notifier_block __cpuinitdata cpucache_notifier = { &cpuup_callback, NULL, 0 }; /* * swap the static kmem_list3 with kmalloced memory */ static void init_list(struct kmem_cache *cachep, struct kmem_list3 *list, int nodeid) { struct kmem_list3 *ptr; ptr = kmalloc_node(sizeof(struct kmem_list3), GFP_KERNEL, nodeid); BUG_ON(!ptr); local_irq_disable(); memcpy(ptr, list, sizeof(struct kmem_list3)); /* * Do not assume that spinlocks can be initialized via memcpy: */ spin_lock_init(&ptr->list_lock); MAKE_ALL_LISTS(cachep, ptr, nodeid); cachep->nodelists[nodeid] = ptr; local_irq_enable(); } /* * For setting up all the kmem_list3s for cache whose buffer_size is same as * size of kmem_list3. */ static void __init set_up_list3s(struct kmem_cache *cachep, int index) { int node; for_each_online_node(node) { cachep->nodelists[node] = &initkmem_list3[index + node]; cachep->nodelists[node]->next_reap = jiffies + REAPTIMEOUT_LIST3 + ((unsigned long)cachep) % REAPTIMEOUT_LIST3; } } /* * Initialisation. Called after the page allocator have been initialised and * before smp_init(). */ void __init kmem_cache_init(void) { size_t left_over; struct cache_sizes *sizes; struct cache_names *names; int i; int order; int node; if (num_possible_nodes() == 1) { use_alien_caches = 0; numa_platform = 0; } for (i = 0; i < NUM_INIT_LISTS; i++) { kmem_list3_init(&initkmem_list3[i]); if (i < MAX_NUMNODES) cache_cache.nodelists[i] = NULL; } set_up_list3s(&cache_cache, CACHE_CACHE); /* * 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 struct * kmem_cache structures of all caches, except cache_cache itself: * cache_cache is statically allocated. * Initially an __init data area is used for the head array and the * kmem_list3 structures, it's replaced with a kmalloc allocated * array at the end of the bootstrap. * 2) Create the first kmalloc cache. * The struct kmem_cache 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) Replace the __init data for kmem_list3 for cache_cache and * the other cache's with kmalloc allocated memory. * 6) Resize the head arrays of the kmalloc caches to their final sizes. */ node = numa_node_id(); /* 1) create the cache_cache */ 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.nodelists[node] = &initkmem_list3[CACHE_CACHE + node]; /* * struct kmem_cache size depends on nr_node_ids, which * can be less than MAX_NUMNODES. */ cache_cache.buffer_size = offsetof(struct kmem_cache, nodelists) + nr_node_ids * sizeof(struct kmem_list3 *); #if DEBUG cache_cache.obj_size = cache_cache.buffer_size; #endif cache_cache.buffer_size = ALIGN(cache_cache.buffer_size, cache_line_size()); cache_cache.reciprocal_buffer_size = reciprocal_value(cache_cache.buffer_size); for (order = 0; order < MAX_ORDER; order++) { cache_estimate(order, cache_cache.buffer_size, cache_line_size(), 0, &left_over, &cache_cache.num); if (cache_cache.num) break; } BUG_ON(!cache_cache.num); cache_cache.gfporder = order; cache_cache.colour = left_over / cache_cache.colour_off; 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; /* * Initialize the caches that provide memory for the array cache and the * kmem_list3 structures first. Without this, further allocations will * bug. */ sizes[INDEX_AC].cs_cachep = kmem_cache_create(names[INDEX_AC].name, sizes[INDEX_AC].cs_size, ARCH_KMALLOC_MINALIGN, ARCH_KMALLOC_FLAGS|SLAB_PANIC, NULL); if (INDEX_AC != INDEX_L3) { sizes[INDEX_L3].cs_cachep = kmem_cache_create(names[INDEX_L3].name, sizes[INDEX_L3].cs_size, ARCH_KMALLOC_MINALIGN, ARCH_KMALLOC_FLAGS|SLAB_PANIC, NULL); } slab_early_init = 0; 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. */ if (!sizes->cs_cachep) { sizes->cs_cachep = kmem_cache_create(names->name, sizes->cs_size, ARCH_KMALLOC_MINALIGN, ARCH_KMALLOC_FLAGS|SLAB_PANIC, NULL); } #ifdef CONFIG_ZONE_DMA sizes->cs_dmacachep = kmem_cache_create( names->name_dma, sizes->cs_size, ARCH_KMALLOC_MINALIGN, ARCH_KMALLOC_FLAGS|SLAB_CACHE_DMA| SLAB_PANIC, NULL); #endif sizes++; names++; } /* 4) Replace the bootstrap head arrays */ { struct array_cache *ptr; ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL); local_irq_disable(); BUG_ON(cpu_cache_get(&cache_cache) != &initarray_cache.cache); memcpy(ptr, cpu_cache_get(&cache_cache), sizeof(struct arraycache_init)); /* * Do not assume that spinlocks can be initialized via memcpy: */ spin_lock_init(&ptr->lock); cache_cache.array[smp_processor_id()] = ptr; local_irq_enable(); ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL); local_irq_disable(); BUG_ON(cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep) != &initarray_generic.cache); memcpy(ptr, cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep), sizeof(struct arraycache_init)); /* * Do not assume that spinlocks can be initialized via memcpy: */ spin_lock_init(&ptr->lock); malloc_sizes[INDEX_AC].cs_cachep->array[smp_processor_id()] = ptr; local_irq_enable(); } /* 5) Replace the bootstrap kmem_list3's */ { int nid; for_each_online_node(nid) { init_list(&cache_cache, &initkmem_list3[CACHE_CACHE + nid], nid); init_list(malloc_sizes[INDEX_AC].cs_cachep, &initkmem_list3[SIZE_AC + nid], nid); if (INDEX_AC != INDEX_L3) { init_list(malloc_sizes[INDEX_L3].cs_cachep, &initkmem_list3[SIZE_L3 + nid], nid); } } } /* 6) resize the head arrays to their final sizes */ { struct kmem_cache *cachep; mutex_lock(&cache_chain_mutex); list_for_each_entry(cachep, &cache_chain, next) if (enable_cpucache(cachep)) BUG(); mutex_unlock(&cache_chain_mutex); } /* Annotate slab for lockdep -- annotate the malloc caches */ init_lock_keys(); /* Done! */ g_cpucache_up = FULL; /* * Register a cpu startup notifier callback that initializes * cpu_cache_get 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 the page allocator */ for_each_online_cpu(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(struct kmem_cache *cachep, gfp_t flags, int nodeid) { struct page *page; int nr_pages; int i; #ifndef CONFIG_MMU /* * Nommu uses slab's for process anonymous memory allocations, and thus * requires __GFP_COMP to properly refcount higher order allocations */ flags |= __GFP_COMP; #endif flags |= cachep->gfpflags; if (cachep->flags & SLAB_RECLAIM_ACCOUNT) flags |= __GFP_RECLAIMABLE; page = alloc_pages_node(nodeid, flags, cachep->gfporder); if (!page) return NULL; nr_pages = (1 << cachep->gfporder); if (cachep->flags & SLAB_RECLAIM_ACCOUNT) add_zone_page_state(page_zone(page), NR_SLAB_RECLAIMABLE, nr_pages); else add_zone_page_state(page_zone(page), NR_SLAB_UNRECLAIMABLE, nr_pages); for (i = 0; i < nr_pages; i++) __SetPageSlab(page + i); return page_address(page); } /* * Interface to system's page release. */ static void kmem_freepages(struct kmem_cache *cachep, void *addr) { unsigned long i = (1 << cachep->gfporder); struct page *page = virt_to_page(addr); const unsigned long nr_freed = i; if (cachep->flags & SLAB_RECLAIM_ACCOUNT) sub_zone_page_state(page_zone(page), NR_SLAB_RECLAIMABLE, nr_freed); else sub_zone_page_state(page_zone(page), NR_SLAB_UNRECLAIMABLE, nr_freed); while (i--) { BUG_ON(!PageSlab(page)); __ClearPageSlab(page); page++; } if (current->reclaim_state) current->reclaim_state->reclaimed_slab += nr_freed; free_pages((unsigned long)addr, cachep->gfporder); } static void kmem_rcu_free(struct rcu_head *head) { struct slab_rcu *slab_rcu = (struct slab_rcu *)head; struct kmem_cache *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(struct kmem_cache *cachep, unsigned long *addr, unsigned long caller) { int size = obj_size(cachep); addr = (unsigned long *)&((char *)addr)[obj_offset(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(struct kmem_cache *cachep, void *addr, unsigned char val) { int size = obj_size(cachep); addr = &((char *)addr)[obj_offset(cachep)]; memset(addr, val, size); *(unsigned char *)(addr + size - 1) = POISON_END; } static void dump_line(char *data, int offset, int limit) { int i; unsigned char error = 0; int bad_count = 0; printk(KERN_ERR "%03x:", offset); for (i = 0; i < limit; i++) { if (data[offset + i] != POISON_FREE) { error = data[offset + i]; bad_count++; } printk(" %02x", (unsigned char)data[offset + i]); } printk("\n"); if (bad_count == 1) { error ^= POISON_FREE; if (!(error & (error - 1))) { printk(KERN_ERR "Single bit error detected. Probably " "bad RAM.\n"); #ifdef CONFIG_X86 printk(KERN_ERR "Run memtest86+ or a similar memory " "test tool.\n"); #else printk(KERN_ERR "Run a memory test tool.\n"); #endif } } } #endif #if DEBUG static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines) { int i, size; char *realobj; if (cachep->flags & SLAB_RED_ZONE) { printk(KERN_ERR "Redzone: 0x%llx/0x%llx.\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_offset(cachep); size = obj_size(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(struct kmem_cache *cachep, void *objp) { char *realobj; int size, i; int lines = 0; realobj = (char *)objp + obj_offset(cachep); size = obj_size(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: %s start=%p, len=%d\n", cachep->name, 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 = virt_to_slab(objp); unsigned int objnr; objnr = obj_to_index(cachep, slabp, objp); if (objnr) { objp = index_to_obj(cachep, slabp, objnr - 1); realobj = (char *)objp + obj_offset(cachep); printk(KERN_ERR "Prev obj: start=%p, len=%d\n", realobj, size); print_objinfo(cachep, objp, 2); } if (objnr + 1 < cachep->num) { objp = index_to_obj(cachep, slabp, objnr + 1); realobj = (char *)objp + obj_offset(cachep); printk(KERN_ERR "Next obj: start=%p, len=%d\n", realobj, size); print_objinfo(cachep, objp, 2); } } } #endif #if DEBUG static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slabp) { int i; for (i = 0; i < cachep->num; i++) { void *objp = index_to_obj(cachep, slabp, i); if (cachep->flags & SLAB_POISON) { #ifdef CONFIG_DEBUG_PAGEALLOC if (cachep->buffer_size % PAGE_SIZE == 0 && OFF_SLAB(cachep)) kernel_map_pages(virt_to_page(objp), cachep->buffer_size / 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"); } } } #else static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slabp) { } #endif /** * slab_destroy - destroy and release all objects in a slab * @cachep: cache pointer being destroyed * @slabp: slab pointer being destroyed * * 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(struct kmem_cache *cachep, struct slab *slabp) { void *addr = slabp->s_mem - slabp->colouroff; slab_destroy_debugcheck(cachep, slabp); 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); } } static void __kmem_cache_destroy(struct kmem_cache *cachep) { int i; struct kmem_list3 *l3; for_each_online_cpu(i) kfree(cachep->array[i]); /* NUMA: free the list3 structures */ for_each_online_node(i) { l3 = cachep->nodelists[i]; if (l3) { kfree(l3->shared); free_alien_cache(l3->alien); kfree(l3); } } kmem_cache_free(&cache_cache, cachep); } /** * calculate_slab_order - calculate size (page order) of slabs * @cachep: pointer to the cache that is being created * @size: size of objects to be created in this cache. * @align: required alignment for the objects. * @flags: slab allocation flags * * Also calculates the number of objects per slab. * * This could be made much more intelligent. For now, try to avoid using * high order pages for slabs. When the gfp() functions are more friendly * towards high-order requests, this should be changed. */ static size_t calculate_slab_order(struct kmem_cache *cachep, size_t size, size_t align, unsigned long flags) { unsigned long offslab_limit; size_t left_over = 0; int gfporder; for (gfporder = 0; gfporder <= KMALLOC_MAX_ORDER; gfporder++) { unsigned int num; size_t remainder; cache_estimate(gfporder, size, align, flags, &remainder, &num); if (!num) continue; if (flags & CFLGS_OFF_SLAB) { /* * Max number of objs-per-slab for caches which * use off-slab slabs. Needed to avoid a possible * looping condition in cache_grow(). */ offslab_limit = size - sizeof(struct slab); offslab_limit /= sizeof(kmem_bufctl_t); if (num > offslab_limit) break; } /* Found something acceptable - save it away */ cachep->num = num; cachep->gfporder = gfporder; left_over = remainder; /* * 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. */ if (flags & SLAB_RECLAIM_ACCOUNT) break; /* * Large number of objects is good, but very large slabs are * currently bad for the gfp()s. */ if (gfporder >= slab_break_gfp_order) break; /* * Acceptable internal fragmentation? */ if (left_over * 8 <= (PAGE_SIZE << gfporder)) break; } return left_over; } static int __init_refok setup_cpu_cache(struct kmem_cache *cachep) { if (g_cpucache_up == FULL) return enable_cpucache(cachep); 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; /* * If the cache that's used by kmalloc(sizeof(kmem_list3)) is * the first cache, then we need to set up all its list3s, * otherwise the creation of further caches will BUG(). */ set_up_list3s(cachep, SIZE_AC); if (INDEX_AC == INDEX_L3) g_cpucache_up = PARTIAL_L3; else g_cpucache_up = PARTIAL_AC; } else { cachep->array[smp_processor_id()] = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL); if (g_cpucache_up == PARTIAL_AC) { set_up_list3s(cachep, SIZE_L3); g_cpucache_up = PARTIAL_L3; } else { int node; for_each_online_node(node) { cachep->nodelists[node] = kmalloc_node(sizeof(struct kmem_list3), GFP_KERNEL, node); BUG_ON(!cachep->nodelists[node]); kmem_list3_init(cachep->nodelists[node]); } } } cachep->nodelists[numa_node_id()]->next_reap = jiffies + REAPTIMEOUT_LIST3 + ((unsigned long)cachep) % REAPTIMEOUT_LIST3; cpu_cache_get(cachep)->avail = 0; cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES; cpu_cache_get(cachep)->batchcount = 1; cpu_cache_get(cachep)->touched = 0; cachep->batchcount = 1; cachep->limit = BOOT_CPUCACHE_ENTRIES; return 0; } /** * 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. * * 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. * * @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_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. */ struct kmem_cache * kmem_cache_create (const char *name, size_t size, size_t align, unsigned long flags, void (*ctor)(void *)) { size_t left_over, slab_size, ralign; struct kmem_cache *cachep = NULL, *pc; /* * Sanity checks... these are all serious usage bugs. */ if (!name || in_interrupt() || (size < BYTES_PER_WORD) || size > KMALLOC_MAX_SIZE) { printk(KERN_ERR "%s: Early error in slab %s\n", __func__, name); BUG(); } /* * We use cache_chain_mutex to ensure a consistent view of * cpu_online_map as well. Please see cpuup_callback */ get_online_cpus(); mutex_lock(&cache_chain_mutex); list_for_each_entry(pc, &cache_chain, next) { char tmp; int res; /* * This happens when the module gets unloaded and doesn't * destroy its slab cache and no-one else reuses the vmalloc * area of the module. Print a warning. */ res = probe_kernel_address(pc->name, tmp); if (res) { printk(KERN_ERR "SLAB: cache with size %d has lost its name\n", pc->buffer_size); continue; } if (!strcmp(pc->name, name)) { printk(KERN_ERR "kmem_cache_create: duplicate cache %s\n", name); dump_stack(); goto oops; } } #if DEBUG WARN_ON(strchr(name, ' ')); /* It confuses parsers */ #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 + REDZONE_ALIGN + 2 * sizeof(unsigned long long))) 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 /* * Always checks flags, a caller might be expecting debug support which * isn't available. */ BUG_ON(flags & ~CREATE_MASK); /* * 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 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; } /* * Redzoning and user store require word alignment or possibly larger. * Note this will be overridden by architecture or caller mandated * alignment if either is greater than BYTES_PER_WORD. */ if (flags & SLAB_STORE_USER) ralign = BYTES_PER_WORD; if (flags & SLAB_RED_ZONE) { ralign = REDZONE_ALIGN; /* If redzoning, ensure that the second redzone is suitably * aligned, by adjusting the object size accordingly. */ size += REDZONE_ALIGN - 1; size &= ~(REDZONE_ALIGN - 1); } /* 2) arch mandated alignment */ if (ralign < ARCH_SLAB_MINALIGN) { ralign = ARCH_SLAB_MINALIGN; } /* 3) caller mandated alignment */ if (ralign < align) { ralign = align; } /* disable debug if necessary */ if (ralign > __alignof__(unsigned long long)) flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); /* * 4) Store it. */ align = ralign; /* Get cache's description obj. */ cachep = kmem_cache_zalloc(&cache_cache, GFP_KERNEL); if (!cachep) goto oops; #if DEBUG cachep->obj_size = size; /* * Both debugging options require word-alignment which is calculated * into align above. */ if (flags & SLAB_RED_ZONE) { /* add space for red zone words */ cachep->obj_offset += sizeof(unsigned long long); size += 2 * sizeof(unsigned long long); } if (flags & SLAB_STORE_USER) { /* user store requires one word storage behind the end of * the real object. But if the second red zone needs to be * aligned to 64 bits, we must allow that much space. */ if (flags & SLAB_RED_ZONE) size += REDZONE_ALIGN; else size += BYTES_PER_WORD; } #if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC) if (size >= malloc_sizes[INDEX_L3 + 1].cs_size && cachep->obj_size > cache_line_size() && size < PAGE_SIZE) { cachep->obj_offset += PAGE_SIZE - size; size = PAGE_SIZE; } #endif #endif /* * Determine if the slab management is 'on' or 'off' slab. * (bootstrapping cannot cope with offslab caches so don't do * it too early on.) */ if ((size >= (PAGE_SIZE >> 3)) && !slab_early_init) /* * 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); left_over = calculate_slab_order(cachep, size, align, flags); if (!cachep->num) { printk(KERN_ERR "kmem_cache_create: couldn't create cache %s.\n", name); kmem_cache_free(&cache_cache, cachep); cachep = NULL; goto oops; } 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 (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA)) cachep->gfpflags |= GFP_DMA; cachep->buffer_size = size; cachep->reciprocal_buffer_size = reciprocal_value(size); if (flags & CFLGS_OFF_SLAB) { cachep->slabp_cache = kmem_find_general_cachep(slab_size, 0u); /* * This is a possibility for one of the malloc_sizes caches. * But since we go off slab only for object size greater than * PAGE_SIZE/8, and malloc_sizes gets created in ascending order, * this should not happen at all. * But leave a BUG_ON for some lucky dude. */ BUG_ON(ZERO_OR_NULL_PTR(cachep->slabp_cache)); } cachep->ctor = ctor; cachep->name = name; if (setup_cpu_cache(cachep)) { __kmem_cache_destroy(cachep); cachep = NULL; goto oops; } /* cache setup completed, link it into the list */ list_add(&cachep->next, &cache_chain); oops: if (!cachep && (flags & SLAB_PANIC)) panic("kmem_cache_create(): failed to create slab `%s'\n", name); mutex_unlock(&cache_chain_mutex); put_online_cpus(); 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(struct kmem_cache *cachep) { #ifdef CONFIG_SMP check_irq_off(); assert_spin_locked(&cachep->nodelists[numa_node_id()]->list_lock); #endif } static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node) { #ifdef CONFIG_SMP check_irq_off(); assert_spin_locked(&cachep->nodelists[node]->list_lock); #endif } #else #define check_irq_off() do { } while(0) #define check_irq_on() do { } while(0) #define check_spinlock_acquired(x) do { } while(0) #define check_spinlock_acquired_node(x, y) do { } while(0) #endif static void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3, struct array_cache *ac, int force, int node); static void do_drain(void *arg) { struct kmem_cache *cachep = arg; struct array_cache *ac; int node = numa_node_id(); check_irq_off(); ac = cpu_cache_get(cachep); spin_lock(&cachep->nodelists[node]->list_lock); free_block(cachep, ac->entry, ac->avail, node); spin_unlock(&cachep->nodelists[node]->list_lock); ac->avail = 0; } static void drain_cpu_caches(struct kmem_cache *cachep) { struct kmem_list3 *l3; int node; on_each_cpu(do_drain, cachep, 1); check_irq_on(); for_each_online_node(node) { l3 = cachep->nodelists[node]; if (l3 && l3->alien) drain_alien_cache(cachep, l3->alien); } for_each_online_node(node) { l3 = cachep->nodelists[node]; if (l3) drain_array(cachep, l3, l3->shared, 1, node); } } /* * Remove slabs from the list of free slabs. * Specify the number of slabs to drain in tofree. * * Returns the actual number of slabs released. */ static int drain_freelist(struct kmem_cache *cache, struct kmem_list3 *l3, int tofree) { struct list_head *p; int nr_freed; struct slab *slabp; nr_freed = 0; while (nr_freed < tofree && !list_empty(&l3->slabs_free)) { spin_lock_irq(&l3->list_lock); p = l3->slabs_free.prev; if (p == &l3->slabs_free) { spin_unlock_irq(&l3->list_lock); goto out; } slabp = list_entry(p, struct slab, list); #if DEBUG BUG_ON(slabp->inuse); #endif list_del(&slabp->list); /* * Safe to drop the lock. The slab is no longer linked * to the cache. */ l3->free_objects -= cache->num; spin_unlock_irq(&l3->list_lock); slab_destroy(cache, slabp); nr_freed++; } out: return nr_freed; } /* Called with cache_chain_mutex held to protect against cpu hotplug */ static int __cache_shrink(struct kmem_cache *cachep) { int ret = 0, i = 0; struct kmem_list3 *l3; drain_cpu_caches(cachep); check_irq_on(); for_each_online_node(i) { l3 = cachep->nodelists[i]; if (!l3) continue; drain_freelist(cachep, l3, l3->free_objects); ret += !list_empty(&l3->slabs_full) || !list_empty(&l3->slabs_partial); } return (ret ? 1 : 0); } /** * 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(struct kmem_cache *cachep) { int ret; BUG_ON(!cachep || in_interrupt()); get_online_cpus(); mutex_lock(&cache_chain_mutex); ret = __cache_shrink(cachep); mutex_unlock(&cache_chain_mutex); put_online_cpus(); return ret; } EXPORT_SYMBOL(kmem_cache_shrink); /** * kmem_cache_destroy - delete a cache * @cachep: the cache to destroy * * Remove a &struct kmem_cache object from the slab cache. * * 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(). */ void kmem_cache_destroy(struct kmem_cache *cachep) { BUG_ON(!cachep || in_interrupt()); /* Find the cache in the chain of caches. */ get_online_cpus(); mutex_lock(&cache_chain_mutex); /* * the chain is never empty, cache_cache is never destroyed */ list_del(&cachep->next); if (__cache_shrink(cachep)) { slab_error(cachep, "Can't free all objects"); list_add(&cachep->next, &cache_chain); mutex_unlock(&cache_chain_mutex); put_online_cpus(); return; } if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) synchronize_rcu(); __kmem_cache_destroy(cachep); mutex_unlock(&cache_chain_mutex); put_online_cpus(); } EXPORT_SYMBOL(kmem_cache_destroy); /* * Get the memory for a slab management obj. * For a slab cache when the slab descriptor is off-slab, slab descriptors * always come from malloc_sizes caches. The slab descriptor cannot * come from the same cache which is getting created because, * when we are searching for an appropriate cache for these * descriptors in kmem_cache_create, we search through the malloc_sizes array. * If we are creating a malloc_sizes cache here it would not be visible to * kmem_find_general_cachep till the initialization is complete. * Hence we cannot have slabp_cache same as the original cache. */ static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp, int colour_off, gfp_t local_flags, int nodeid) { struct slab *slabp; if (OFF_SLAB(cachep)) { /* Slab management obj is off-slab. */ slabp = kmem_cache_alloc_node(cachep->slabp_cache, local_flags & ~GFP_THISNODE, nodeid); 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; slabp->nodeid = nodeid; slabp->free = 0; return slabp; } static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp) { return (kmem_bufctl_t *) (slabp + 1); } static void cache_init_objs(struct kmem_cache *cachep, struct slab *slabp) { int i; for (i = 0; i < cachep->num; i++) { void *objp = index_to_obj(cachep, slabp, 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_offset(cachep)); 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->buffer_size % PAGE_SIZE) == 0 && OFF_SLAB(cachep) && cachep->flags & SLAB_POISON) kernel_map_pages(virt_to_page(objp), cachep->buffer_size / PAGE_SIZE, 0); #else if (cachep->ctor) cachep->ctor(objp); #endif slab_bufctl(slabp)[i] = i + 1; } slab_bufctl(slabp)[i - 1] = BUFCTL_END; } static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags) { if (CONFIG_ZONE_DMA_FLAG) { if (flags & GFP_DMA) BUG_ON(!(cachep->gfpflags & GFP_DMA)); else BUG_ON(cachep->gfpflags & GFP_DMA); } } static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp, int nodeid) { void *objp = index_to_obj(cachep, slabp, slabp->free); kmem_bufctl_t next; slabp->inuse++; next = slab_bufctl(slabp)[slabp->free]; #if DEBUG slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE; WARN_ON(slabp->nodeid != nodeid); #endif slabp->free = next; return objp; } static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp, void *objp, int nodeid) { unsigned int objnr = obj_to_index(cachep, slabp, objp); #if DEBUG /* Verify that the slab belongs to the intended node */ WARN_ON(slabp->nodeid != nodeid); if (slab_bufctl(slabp)[objnr] + 1 <= SLAB_LIMIT + 1) { 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; slabp->inuse--; } /* * Map pages beginning at addr to the given cache and slab. This is required * for the slab allocator to be able to lookup the cache and slab of a * virtual address for kfree, ksize, kmem_ptr_validate, and slab debugging. */ static void slab_map_pages(struct kmem_cache *cache, struct slab *slab, void *addr) { int nr_pages; struct page *page; page = virt_to_page(addr); nr_pages = 1; if (likely(!PageCompound(page))) nr_pages <<= cache->gfporder; do { page_set_cache(page, cache); page_set_slab(page, slab); page++; } while (--nr_pages); } /* * 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(struct kmem_cache *cachep, gfp_t flags, int nodeid, void *objp) { struct slab *slabp; size_t offset; gfp_t local_flags; struct kmem_list3 *l3; /* * Be lazy and only check for valid flags here, keeping it out of the * critical path in kmem_cache_alloc(). */ BUG_ON(flags & GFP_SLAB_BUG_MASK); local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK); /* Take the l3 list lock to change the colour_next on this node */ check_irq_off(); l3 = cachep->nodelists[nodeid]; spin_lock(&l3->list_lock); /* Get colour for the slab, and cal the next value. */ offset = l3->colour_next; l3->colour_next++; if (l3->colour_next >= cachep->colour) l3->colour_next = 0; spin_unlock(&l3->list_lock); offset *= cachep->colour_off; 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. Attempt to allocate a physical page from * 'nodeid'. */ if (!objp) objp = kmem_getpages(cachep, local_flags, nodeid); if (!objp) goto failed; /* Get slab management. */ slabp = alloc_slabmgmt(cachep, objp, offset, local_flags & ~GFP_CONSTRAINT_MASK, nodeid); if (!slabp) goto opps1; slab_map_pages(cachep, slabp, objp); cache_init_objs(cachep, slabp); if (local_flags & __GFP_WAIT) local_irq_disable(); check_irq_off(); spin_lock(&l3->list_lock); /* Make slab active. */ list_add_tail(&slabp->list, &(l3->slabs_free)); STATS_INC_GROWN(cachep); l3->free_objects += cachep->num; spin_unlock(&l3->list_lock); 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 */ static void kfree_debugcheck(const void *objp) { if (!virt_addr_valid(objp)) { printk(KERN_ERR "kfree_debugcheck: out of range ptr %lxh.\n", (unsigned long)objp); BUG(); } } static inline void verify_redzone_free(struct kmem_cache *cache, void *obj) { unsigned long long redzone1, redzone2; redzone1 = *dbg_redzone1(cache, obj); redzone2 = *dbg_redzone2(cache, obj); /* * Redzone is ok. */ if (redzone1 == RED_ACTIVE && redzone2 == RED_ACTIVE) return; if (redzone1 == RED_INACTIVE && redzone2 == RED_INACTIVE) slab_error(cache, "double free detected"); else slab_error(cache, "memory outside object was overwritten"); printk(KERN_ERR "%p: redzone 1:0x%llx, redzone 2:0x%llx.\n", obj, redzone1, redzone2); } static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp, void *caller) { struct page *page; unsigned int objnr; struct slab *slabp; BUG_ON(virt_to_cache(objp) != cachep); objp -= obj_offset(cachep); kfree_debugcheck(objp); page = virt_to_head_page(objp); slabp = page_get_slab(page); if (cachep->flags & SLAB_RED_ZONE) { verify_redzone_free(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 = obj_to_index(cachep, slabp, objp); BUG_ON(objnr >= cachep->num); BUG_ON(objp != index_to_obj(cachep, slabp, objnr)); #ifdef CONFIG_DEBUG_SLAB_LEAK slab_bufctl(slabp)[objnr] = BUFCTL_FREE; #endif if (cachep->flags & SLAB_POISON) { #ifdef CONFIG_DEBUG_PAGEALLOC if ((cachep->buffer_size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) { store_stackinfo(cachep, objp, (unsigned long)caller); kernel_map_pages(virt_to_page(objp), cachep->buffer_size / PAGE_SIZE, 0); } else { poison_obj(cachep, objp, POISON_FREE); } #else poison_obj(cachep, objp, POISON_FREE); #endif } return objp; } static void check_slabp(struct kmem_cache *cachep, struct slab *slabp) { kmem_bufctl_t i; int entries = 0; /* 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(struct kmem_cache *cachep, gfp_t flags) { int batchcount; struct kmem_list3 *l3; struct array_cache *ac; int node; retry: check_irq_off(); node = numa_node_id(); ac = cpu_cache_get(cachep); 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 = cachep->nodelists[node]; BUG_ON(ac->avail > 0 || !l3); spin_lock(&l3->list_lock); /* See if we can refill from the shared array */ if (l3->shared && transfer_objects(ac, l3->shared, batchcount)) 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); /* * The slab was either on partial or free list so * there must be at least one object available for * allocation. */ BUG_ON(slabp->inuse < 0 || slabp->inuse >= cachep->num); while (slabp->inuse < cachep->num && batchcount--) { STATS_INC_ALLOCED(cachep); STATS_INC_ACTIVE(cachep); STATS_SET_HIGH(cachep); ac->entry[ac->avail++] = slab_get_obj(cachep, slabp, node); } 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(&l3->list_lock); if (unlikely(!ac->avail)) { int x; x = cache_grow(cachep, flags | GFP_THISNODE, node, NULL); /* cache_grow can reenable interrupts, then ac could change. */ ac = cpu_cache_get(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->avail]; } static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep, gfp_t flags) { might_sleep_if(flags & __GFP_WAIT); #if DEBUG kmem_flagcheck(cachep, flags); #endif } #if DEBUG static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep, gfp_t flags, void *objp, void *caller) { if (!objp) return objp; if (cachep->flags & SLAB_POISON) { #ifdef CONFIG_DEBUG_PAGEALLOC if ((cachep->buffer_size % PAGE_SIZE) == 0 && OFF_SLAB(cachep)) kernel_map_pages(virt_to_page(objp), cachep->buffer_size / 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%llx, redzone 2:0x%llx\n", objp, *dbg_redzone1(cachep, objp), *dbg_redzone2(cachep, objp)); } *dbg_redzone1(cachep, objp) = RED_ACTIVE; *dbg_redzone2(cachep, objp) = RED_ACTIVE; } #ifdef CONFIG_DEBUG_SLAB_LEAK { struct slab *slabp; unsigned objnr; slabp = page_get_slab(virt_to_head_page(objp)); objnr = (unsigned)(objp - slabp->s_mem) / cachep->buffer_size; slab_bufctl(slabp)[objnr] = BUFCTL_ACTIVE; } #endif objp += obj_offset(cachep); if (cachep->ctor && cachep->flags & SLAB_POISON) cachep->ctor(objp); #if ARCH_SLAB_MINALIGN if ((u32)objp & (ARCH_SLAB_MINALIGN-1)) { printk(KERN_ERR "0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n", objp, ARCH_SLAB_MINALIGN); } #endif return objp; } #else #define cache_alloc_debugcheck_after(a,b,objp,d) (objp) #endif #ifdef CONFIG_FAILSLAB static struct failslab_attr { struct fault_attr attr; u32 ignore_gfp_wait; #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS struct dentry *ignore_gfp_wait_file; #endif } failslab = { .attr = FAULT_ATTR_INITIALIZER, .ignore_gfp_wait = 1, }; static int __init setup_failslab(char *str) { return setup_fault_attr(&failslab.attr, str); } __setup("failslab=", setup_failslab); static int should_failslab(struct kmem_cache *cachep, gfp_t flags) { if (cachep == &cache_cache) return 0; if (flags & __GFP_NOFAIL) return 0; if (failslab.ignore_gfp_wait && (flags & __GFP_WAIT)) return 0; return should_fail(&failslab.attr, obj_size(cachep)); } #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS static int __init failslab_debugfs(void) { mode_t mode = S_IFREG | S_IRUSR | S_IWUSR; struct dentry *dir; int err; err = init_fault_attr_dentries(&failslab.attr, "failslab"); if (err) return err; dir = failslab.attr.dentries.dir; failslab.ignore_gfp_wait_file = debugfs_create_bool("ignore-gfp-wait", mode, dir, &failslab.ignore_gfp_wait); if (!failslab.ignore_gfp_wait_file) { err = -ENOMEM; debugfs_remove(failslab.ignore_gfp_wait_file); cleanup_fault_attr_dentries(&failslab.attr); } return err; } late_initcall(failslab_debugfs); #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ #else /* CONFIG_FAILSLAB */ static inline int should_failslab(struct kmem_cache *cachep, gfp_t flags) { return 0; } #endif /* CONFIG_FAILSLAB */ static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags) { void *objp; struct array_cache *ac; check_irq_off(); ac = cpu_cache_get(cachep); if (likely(ac->avail)) { STATS_INC_ALLOCHIT(cachep); ac->touched = 1; objp = ac->entry[--ac->avail]; } else { STATS_INC_ALLOCMISS(cachep); objp = cache_alloc_refill(cachep, flags); } return objp; } #ifdef CONFIG_NUMA /* * Try allocating on another node if PF_SPREAD_SLAB|PF_MEMPOLICY. * * If we are in_interrupt, then process context, including cpusets and * mempolicy, may not apply and should not be used for allocation policy. */ static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags) { int nid_alloc, nid_here; if (in_interrupt() || (flags & __GFP_THISNODE)) return NULL; nid_alloc = nid_here = numa_node_id(); if (cpuset_do_slab_mem_spread() && (cachep->flags & SLAB_MEM_SPREAD)) nid_alloc = cpuset_mem_spread_node(); else if (current->mempolicy) nid_alloc = slab_node(current->mempolicy); if (nid_alloc != nid_here) return ____cache_alloc_node(cachep, flags, nid_alloc); return NULL; } /* * Fallback function if there was no memory available and no objects on a * certain node and fall back is permitted. First we scan all the * available nodelists for available objects. If that fails then we * perform an allocation without specifying a node. This allows the page * allocator to do its reclaim / fallback magic. We then insert the * slab into the proper nodelist and then allocate from it. */ static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags) { struct zonelist *zonelist; gfp_t local_flags; struct zoneref *z; struct zone *zone; enum zone_type high_zoneidx = gfp_zone(flags); void *obj = NULL; int nid; if (flags & __GFP_THISNODE) return NULL; zonelist = node_zonelist(slab_node(current->mempolicy), flags); local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK); retry: /* * Look through allowed nodes for objects available * from existing per node queues. */ for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) { nid = zone_to_nid(zone); if (cpuset_zone_allowed_hardwall(zone, flags) && cache->nodelists[nid] && cache->nodelists[nid]->free_objects) { obj = ____cache_alloc_node(cache, flags | GFP_THISNODE, nid); if (obj) break; } } if (!obj) { /* * This allocation will be performed within the constraints * of the current cpuset / memory policy requirements. * We may trigger various forms of reclaim on the allowed * set and go into memory reserves if necessary. */ if (local_flags & __GFP_WAIT) local_irq_enable(); kmem_flagcheck(cache, flags); obj = kmem_getpages(cache, local_flags, -1); if (local_flags & __GFP_WAIT) local_irq_disable(); if (obj) { /* * Insert into the appropriate per node queues */ nid = page_to_nid(virt_to_page(obj)); if (cache_grow(cache, flags, nid, obj)) { obj = ____cache_alloc_node(cache, flags | GFP_THISNODE, nid); if (!obj) /* * Another processor may allocate the * objects in the slab since we are * not holding any locks. */ goto retry; } else { /* cache_grow already freed obj */ obj = NULL; } } } return obj; } /* * A interface to enable slab creation on nodeid */ static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid) { struct list_head *entry; struct slab *slabp; struct kmem_list3 *l3; void *obj; int x; l3 = cachep->nodelists[nodeid]; BUG_ON(!l3); retry: check_irq_off(); spin_lock(&l3->list_lock); 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_spinlock_acquired_node(cachep, nodeid); check_slabp(cachep, slabp); STATS_INC_NODEALLOCS(cachep); STATS_INC_ACTIVE(cachep); STATS_SET_HIGH(cachep); BUG_ON(slabp->inuse == cachep->num); obj = slab_get_obj(cachep, slabp, nodeid); check_slabp(cachep, slabp); l3->free_objects--; /* 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); spin_unlock(&l3->list_lock); goto done; must_grow: spin_unlock(&l3->list_lock); x = cache_grow(cachep, flags | GFP_THISNODE, nodeid, NULL); if (x) goto retry; return fallback_alloc(cachep, flags); done: return obj; } /** * 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. * @caller: return address of caller, used for debug information * * Identical to kmem_cache_alloc but it will allocate memory on the given * node, which can improve the performance for cpu bound structures. * * Fallback to other node is possible if __GFP_THISNODE is not set. */ static __always_inline void * __cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid, void *caller) { unsigned long save_flags; void *ptr; if (should_failslab(cachep, flags)) return NULL; cache_alloc_debugcheck_before(cachep, flags); local_irq_save(save_flags); if (unlikely(nodeid == -1)) nodeid = numa_node_id(); if (unlikely(!cachep->nodelists[nodeid])) { /* Node not bootstrapped yet */ ptr = fallback_alloc(cachep, flags); goto out; } if (nodeid == numa_node_id()) { /* * Use the locally cached objects if possible. * However ____cache_alloc does not allow fallback * to other nodes. It may fail while we still have * objects on other nodes available. */ ptr = ____cache_alloc(cachep, flags); if (ptr) goto out; } /* ___cache_alloc_node can fall back to other nodes */ ptr = ____cache_alloc_node(cachep, flags, nodeid); out: local_irq_restore(save_flags); ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller); if (unlikely((flags & __GFP_ZERO) && ptr)) memset(ptr, 0, obj_size(cachep)); return ptr; } static __always_inline void * __do_cache_alloc(struct kmem_cache *cache, gfp_t flags) { void *objp; if (unlikely(current->flags & (PF_SPREAD_SLAB | PF_MEMPOLICY))) { objp = alternate_node_alloc(cache, flags); if (objp) goto out; } objp = ____cache_alloc(cache, flags); /* * We may just have run out of memory on the local node. * ____cache_alloc_node() knows how to locate memory on other nodes */ if (!objp) objp = ____cache_alloc_node(cache, flags, numa_node_id()); out: return objp; } #else static __always_inline void * __do_cache_alloc(struct kmem_cache *cachep, gfp_t flags) { return ____cache_alloc(cachep, flags); } #endif /* CONFIG_NUMA */ static __always_inline void * __cache_alloc(struct kmem_cache *cachep, gfp_t flags, void *caller) { unsigned long save_flags; void *objp; if (should_failslab(cachep, flags)) return NULL; cache_alloc_debugcheck_before(cachep, flags); local_irq_save(save_flags); objp = __do_cache_alloc(cachep, flags); local_irq_restore(save_flags); objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller); prefetchw(objp); if (unlikely((flags & __GFP_ZERO) && objp)) memset(objp, 0, obj_size(cachep)); return objp; } /* * Caller needs to acquire correct kmem_list's list_lock */ static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects, int node) { int i; struct kmem_list3 *l3; for (i = 0; i < nr_objects; i++) { void *objp = objpp[i]; struct slab *slabp; slabp = virt_to_slab(objp); l3 = cachep->nodelists[node]; list_del(&slabp->list); check_spinlock_acquired_node(cachep, node); check_slabp(cachep, slabp); slab_put_obj(cachep, slabp, objp, node); STATS_DEC_ACTIVE(cachep); l3->free_objects++; check_slabp(cachep, slabp); /* fixup slab chains */ if (slabp->inuse == 0) { if (l3->free_objects > l3->free_limit) { l3->free_objects -= cachep->num; /* No need to drop any previously held * lock here, even if we have a off-slab slab * descriptor it is guaranteed to come from * a different cache, refer to comments before * alloc_slabmgmt. */ slab_destroy(cachep, slabp); } else { list_add(&slabp->list, &l3->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, &l3->slabs_partial); } } } static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac) { int batchcount; struct kmem_list3 *l3; int node = numa_node_id(); batchcount = ac->batchcount; #if DEBUG BUG_ON(!batchcount || batchcount > ac->avail); #endif check_irq_off(); l3 = cachep->nodelists[node]; spin_lock(&l3->list_lock); if (l3->shared) { struct array_cache *shared_array = l3->shared; int max = shared_array->limit - shared_array->avail; if (max) { if (batchcount > max) batchcount = max; memcpy(&(shared_array->entry[shared_array->avail]), ac->entry, sizeof(void *) * batchcount); shared_array->avail += batchcount; goto free_done; } } free_block(cachep, ac->entry, batchcount, node); free_done: #if STATS { int i = 0; struct list_head *p; p = l3->slabs_free.next; while (p != &(l3->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(&l3->list_lock); ac->avail -= batchcount; memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail); } /* * 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(struct kmem_cache *cachep, void *objp) { struct array_cache *ac = cpu_cache_get(cachep); check_irq_off(); objp = cache_free_debugcheck(cachep, objp, __builtin_return_address(0)); /* * Skip calling cache_free_alien() when the platform is not numa. * This will avoid cache misses that happen while accessing slabp (which * is per page memory reference) to get nodeid. Instead use a global * variable to skip the call, which is mostly likely to be present in * the cache. */ if (numa_platform && cache_free_alien(cachep, objp)) return; if (likely(ac->avail < ac->limit)) { STATS_INC_FREEHIT(cachep); ac->entry[ac->avail++] = objp; return; } else { STATS_INC_FREEMISS(cachep); cache_flusharray(cachep, ac); ac->entry[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(struct kmem_cache *cachep, gfp_t flags) { return __cache_alloc(cachep, flags, __builtin_return_address(0)); } 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 kmem_ptr_validate(struct kmem_cache *cachep, const 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->buffer_size; 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(page_get_cache(page) != cachep)) goto out; return 1; out: return 0; } #ifdef CONFIG_NUMA void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid) { return __cache_alloc_node(cachep, flags, nodeid, __builtin_return_address(0)); } EXPORT_SYMBOL(kmem_cache_alloc_node); static __always_inline void * __do_kmalloc_node(size_t size, gfp_t flags, int node, void *caller) { struct kmem_cache *cachep; cachep = kmem_find_general_cachep(size, flags); if (unlikely(ZERO_OR_NULL_PTR(cachep))) return cachep; return kmem_cache_alloc_node(cachep, flags, node); } #ifdef CONFIG_DEBUG_SLAB void *__kmalloc_node(size_t size, gfp_t flags, int node) { return __do_kmalloc_node(size, flags, node, __builtin_return_address(0)); } EXPORT_SYMBOL(__kmalloc_node); void *__kmalloc_node_track_caller(size_t size, gfp_t flags, int node, void *caller) { return __do_kmalloc_node(size, flags, node, caller); } EXPORT_SYMBOL(__kmalloc_node_track_caller); #else void *__kmalloc_node(size_t size, gfp_t flags, int node) { return __do_kmalloc_node(size, flags, node, NULL); } EXPORT_SYMBOL(__kmalloc_node); #endif /* CONFIG_DEBUG_SLAB */ #endif /* CONFIG_NUMA */ /** * __do_kmalloc - allocate memory * @size: how many bytes of memory are required. * @flags: the type of memory to allocate (see kmalloc). * @caller: function caller for debug tracking of the caller */ static __always_inline void *__do_kmalloc(size_t size, gfp_t flags, void *caller) { struct kmem_cache *cachep; /* If you want to save a few bytes .text space: replace * __ with kmem_. * Then kmalloc uses the uninlined functions instead of the inline * functions. */ cachep = __find_general_cachep(size, flags); if (unlikely(ZERO_OR_NULL_PTR(cachep))) return cachep; return __cache_alloc(cachep, flags, caller); } #ifdef CONFIG_DEBUG_SLAB void *__kmalloc(size_t size, gfp_t flags) { return __do_kmalloc(size, flags, __builtin_return_address(0)); } EXPORT_SYMBOL(__kmalloc); void *__kmalloc_track_caller(size_t size, gfp_t flags, void *caller) { return __do_kmalloc(size, flags, caller); } EXPORT_SYMBOL(__kmalloc_track_caller); #else void *__kmalloc(size_t size, gfp_t flags) { return __do_kmalloc(size, flags, NULL); } EXPORT_SYMBOL(__kmalloc); #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(struct kmem_cache *cachep, void *objp) { unsigned long flags; local_irq_save(flags); debug_check_no_locks_freed(objp, obj_size(cachep)); if (!(cachep->flags & SLAB_DEBUG_OBJECTS)) debug_check_no_obj_freed(objp, obj_size(cachep)); __cache_free(cachep, objp); local_irq_restore(flags); } EXPORT_SYMBOL(kmem_cache_free); /** * kfree - free previously allocated memory * @objp: pointer returned by kmalloc. * * If @objp is NULL, no operation is performed. * * Don't free memory not originally allocated by kmalloc() * or you will run into trouble. */ void kfree(const void *objp) { struct kmem_cache *c; unsigned long flags; if (unlikely(ZERO_OR_NULL_PTR(objp))) return; local_irq_save(flags); kfree_debugcheck(objp); c = virt_to_cache(objp); debug_check_no_locks_freed(objp, obj_size(c)); debug_check_no_obj_freed(objp, obj_size(c)); __cache_free(c, (void *)objp); local_irq_restore(flags); } EXPORT_SYMBOL(kfree); unsigned int kmem_cache_size(struct kmem_cache *cachep) { return obj_size(cachep); } EXPORT_SYMBOL(kmem_cache_size); const char *kmem_cache_name(struct kmem_cache *cachep) { return cachep->name; } EXPORT_SYMBOL_GPL(kmem_cache_name); /* * This initializes kmem_list3 or resizes various caches for all nodes. */ static int alloc_kmemlist(struct kmem_cache *cachep) { int node; struct kmem_list3 *l3; struct array_cache *new_shared; struct array_cache **new_alien = NULL; for_each_online_node(node) { if (use_alien_caches) { new_alien = alloc_alien_cache(node, cachep->limit); if (!new_alien) goto fail; } new_shared = NULL; if (cachep->shared) { new_shared = alloc_arraycache(node, cachep->shared*cachep->batchcount, 0xbaadf00d); if (!new_shared) { free_alien_cache(new_alien); goto fail; } } l3 = cachep->nodelists[node]; if (l3) { struct array_cache *shared = l3->shared; spin_lock_irq(&l3->list_lock); if (shared) free_block(cachep, shared->entry, shared->avail, node); l3->shared = new_shared; if (!l3->alien) { l3->alien = new_alien; new_alien = NULL; } l3->free_limit = (1 + nr_cpus_node(node)) * cachep->batchcount + cachep->num; spin_unlock_irq(&l3->list_lock); kfree(shared); free_alien_cache(new_alien); continue; } l3 = kmalloc_node(sizeof(struct kmem_list3), GFP_KERNEL, node); if (!l3) { free_alien_cache(new_alien); kfree(new_shared); goto fail; } kmem_list3_init(l3); l3->next_reap = jiffies + REAPTIMEOUT_LIST3 + ((unsigned long)cachep) % REAPTIMEOUT_LIST3; l3->shared = new_shared; l3->alien = new_alien; l3->free_limit = (1 + nr_cpus_node(node)) * cachep->batchcount + cachep->num; cachep->nodelists[node] = l3; } return 0; fail: if (!cachep->next.next) { /* Cache is not active yet. Roll back what we did */ node--; while (node >= 0) { if (cachep->nodelists[node]) { l3 = cachep->nodelists[node]; kfree(l3->shared); free_alien_cache(l3->alien); kfree(l3); cachep->nodelists[node] = NULL; } node--; } } return -ENOMEM; } struct ccupdate_struct { struct kmem_cache *cachep; struct array_cache *new[NR_CPUS]; }; static void do_ccupdate_local(void *info) { struct ccupdate_struct *new = info; struct array_cache *old; check_irq_off(); old = cpu_cache_get(new->cachep); new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()]; new->new[smp_processor_id()] = old; } /* Always called with the cache_chain_mutex held */ static int do_tune_cpucache(struct kmem_cache *cachep, int limit, int batchcount, int shared) { struct ccupdate_struct *new; int i; new = kzalloc(sizeof(*new), GFP_KERNEL); if (!new) return -ENOMEM; for_each_online_cpu(i) { new->new[i] = alloc_arraycache(cpu_to_node(i), limit, batchcount); if (!new->new[i]) { for (i--; i >= 0; i--) kfree(new->new[i]); kfree(new); return -ENOMEM; } } new->cachep = cachep; on_each_cpu(do_ccupdate_local, (void *)new, 1); check_irq_on(); cachep->batchcount = batchcount; cachep->limit = limit; cachep->shared = shared; for_each_online_cpu(i) { struct array_cache *ccold = new->new[i]; if (!ccold) continue; spin_lock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock); free_block(cachep, ccold->entry, ccold->avail, cpu_to_node(i)); spin_unlock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock); kfree(ccold); } kfree(new); return alloc_kmemlist(cachep); } /* Called with cache_chain_mutex held always */ static int enable_cpucache(struct kmem_cache *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->buffer_size > 131072) limit = 1; else if (cachep->buffer_size > PAGE_SIZE) limit = 8; else if (cachep->buffer_size > 1024) limit = 24; else if (cachep->buffer_size > 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; if (cachep->buffer_size <= PAGE_SIZE && num_possible_cpus() > 1) shared = 8; #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); return err; } /* * Drain an array if it contains any elements taking the l3 lock only if * necessary. Note that the l3 listlock also protects the array_cache * if drain_array() is used on the shared array. */ void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3, struct array_cache *ac, int force, int node) { int tofree; if (!ac || !ac->avail) return; if (ac->touched && !force) { ac->touched = 0; } else { spin_lock_irq(&l3->list_lock); 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, tofree, node); ac->avail -= tofree; memmove(ac->entry, &(ac->entry[tofree]), sizeof(void *) * ac->avail); } spin_unlock_irq(&l3->list_lock); } } /** * cache_reap - Reclaim memory from caches. * @w: work descriptor * * 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 mutex then just give up - we'll try * again on the next iteration. */ static void cache_reap(struct work_struct *w) { struct kmem_cache *searchp; struct kmem_list3 *l3; int node = numa_node_id(); struct delayed_work *work = container_of(w, struct delayed_work, work); if (!mutex_trylock(&cache_chain_mutex)) /* Give up. Setup the next iteration. */ goto out; list_for_each_entry(searchp, &cache_chain, next) { check_irq_on(); /* * We only take the l3 lock if absolutely necessary and we * have established with reasonable certainty that * we can do some work if the lock was obtained. */ l3 = searchp->nodelists[node]; reap_alien(searchp, l3); drain_array(searchp, l3, cpu_cache_get(searchp), 0, node); /* * These are racy checks but it does not matter * if we skip one check or scan twice. */ if (time_after(l3->next_reap, jiffies)) goto next; l3->next_reap = jiffies + REAPTIMEOUT_LIST3; drain_array(searchp, l3, l3->shared, 0, node); if (l3->free_touched) l3->free_touched = 0; else { int freed; freed = drain_freelist(searchp, l3, (l3->free_limit + 5 * searchp->num - 1) / (5 * searchp->num)); STATS_ADD_REAPED(searchp, freed); } next: cond_resched(); } check_irq_on(); mutex_unlock(&cache_chain_mutex); next_reap_node(); out: /* Set up the next iteration */ schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_CPUC)); } #ifdef CONFIG_SLABINFO static void print_slabinfo_header(struct seq_file *m) { /* * 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> <nodeallocs> <remotefrees> <alienoverflow>"); seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>"); #endif seq_putc(m, '\n'); } static void *s_start(struct seq_file *m, loff_t *pos) { loff_t n = *pos; mutex_lock(&cache_chain_mutex); if (!n) print_slabinfo_header(m); return seq_list_start(&cache_chain, *pos); } static void *s_next(struct seq_file *m, void *p, loff_t *pos) { return seq_list_next(p, &cache_chain, pos); } static void s_stop(struct seq_file *m, void *p) { mutex_unlock(&cache_chain_mutex); } static int s_show(struct seq_file *m, void *p) { struct kmem_cache *cachep = list_entry(p, struct kmem_cache, next); struct slab *slabp; unsigned long active_objs; unsigned long num_objs; unsigned long active_slabs = 0; unsigned long num_slabs, free_objects = 0, shared_avail = 0; const char *name; char *error = NULL; int node; struct kmem_list3 *l3; active_objs = 0; num_slabs = 0; for_each_online_node(node) { l3 = cachep->nodelists[node]; if (!l3) continue; check_irq_on(); spin_lock_irq(&l3->list_lock); list_for_each_entry(slabp, &l3->slabs_full, list) { if (slabp->inuse != cachep->num && !error) error = "slabs_full accounting error"; active_objs += cachep->num; active_slabs++; } list_for_each_entry(slabp, &l3->slabs_partial, 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_entry(slabp, &l3->slabs_free, list) { if (slabp->inuse && !error) error = "slabs_free/inuse accounting error"; num_slabs++; } free_objects += l3->free_objects; if (l3->shared) shared_avail += l3->shared->avail; spin_unlock_irq(&l3->list_lock); } num_slabs += active_slabs; num_objs = num_slabs * cachep->num; if (num_objs - active_objs != 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->buffer_size, cachep->num, (1 << cachep->gfporder)); seq_printf(m, " : tunables %4u %4u %4u", cachep->limit, cachep->batchcount, cachep->shared); seq_printf(m, " : slabdata %6lu %6lu %6lu", active_slabs, num_slabs, 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 node_allocs = cachep->node_allocs; unsigned long node_frees = cachep->node_frees; unsigned long overflows = cachep->node_overflow; seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu \ %4lu %4lu %4lu %4lu %4lu", allocs, high, grown, reaped, errors, max_freeable, node_allocs, node_frees, overflows); } /* 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'); 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 */ const 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 kmem_cache *cachep; 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. */ mutex_lock(&cache_chain_mutex); res = -EINVAL; list_for_each_entry(cachep, &cache_chain, next) { if (!strcmp(cachep->name, kbuf)) { if (limit < 1 || batchcount < 1 || batchcount > limit || shared < 0) { res = 0; } else { res = do_tune_cpucache(cachep, limit, batchcount, shared); } break; } } mutex_unlock(&cache_chain_mutex); if (res >= 0) res = count; return res; } #ifdef CONFIG_DEBUG_SLAB_LEAK static void *leaks_start(struct seq_file *m, loff_t *pos) { mutex_lock(&cache_chain_mutex); return seq_list_start(&cache_chain, *pos); } static inline int add_caller(unsigned long *n, unsigned long v) { unsigned long *p; int l; if (!v) return 1; l = n[1]; p = n + 2; while (l) { int i = l/2; unsigned long *q = p + 2 * i; if (*q == v) { q[1]++; return 1; } if (*q > v) { l = i; } else { p = q + 2; l -= i + 1; } } if (++n[1] == n[0]) return 0; memmove(p + 2, p, n[1] * 2 * sizeof(unsigned long) - ((void *)p - (void *)n)); p[0] = v; p[1] = 1; return 1; } static void handle_slab(unsigned long *n, struct kmem_cache *c, struct slab *s) { void *p; int i; if (n[0] == n[1]) return; for (i = 0, p = s->s_mem; i < c->num; i++, p += c->buffer_size) { if (slab_bufctl(s)[i] != BUFCTL_ACTIVE) continue; if (!add_caller(n, (unsigned long)*dbg_userword(c, p))) return; } } static void show_symbol(struct seq_file *m, unsigned long address) { #ifdef CONFIG_KALLSYMS unsigned long offset, size; char modname[MODULE_NAME_LEN], name[KSYM_NAME_LEN]; if (lookup_symbol_attrs(address, &size, &offset, modname, name) == 0) { seq_printf(m, "%s+%#lx/%#lx", name, offset, size); if (modname[0]) seq_printf(m, " [%s]", modname); return; } #endif seq_printf(m, "%p", (void *)address); } static int leaks_show(struct seq_file *m, void *p) { struct kmem_cache *cachep = list_entry(p, struct kmem_cache, next); struct slab *slabp; struct kmem_list3 *l3; const char *name; unsigned long *n = m->private; int node; int i; if (!(cachep->flags & SLAB_STORE_USER)) return 0; if (!(cachep->flags & SLAB_RED_ZONE)) return 0; /* OK, we can do it */ n[1] = 0; for_each_online_node(node) { l3 = cachep->nodelists[node]; if (!l3) continue; check_irq_on(); spin_lock_irq(&l3->list_lock); list_for_each_entry(slabp, &l3->slabs_full, list) handle_slab(n, cachep, slabp); list_for_each_entry(slabp, &l3->slabs_partial, list) handle_slab(n, cachep, slabp); spin_unlock_irq(&l3->list_lock); } name = cachep->name; if (n[0] == n[1]) { /* Increase the buffer size */ mutex_unlock(&cache_chain_mutex); m->private = kzalloc(n[0] * 4 * sizeof(unsigned long), GFP_KERNEL); if (!m->private) { /* Too bad, we are really out */ m->private = n; mutex_lock(&cache_chain_mutex); return -ENOMEM; } *(unsigned long *)m->private = n[0] * 2; kfree(n); mutex_lock(&cache_chain_mutex); /* Now make sure this entry will be retried */ m->count = m->size; return 0; } for (i = 0; i < n[1]; i++) { seq_printf(m, "%s: %lu ", name, n[2*i+3]); show_symbol(m, n[2*i+2]); seq_putc(m, '\n'); } return 0; } static const struct seq_operations slabstats_op = { .start = leaks_start, .next = s_next, .stop = s_stop, .show = leaks_show, }; static int slabstats_open(struct inode *inode, struct file *file) { unsigned long *n = kzalloc(PAGE_SIZE, GFP_KERNEL); int ret = -ENOMEM; if (n) { ret = seq_open(file, &slabstats_op); if (!ret) { struct seq_file *m = file->private_data; *n = PAGE_SIZE / (2 * sizeof(unsigned long)); m->private = n; n = NULL; } kfree(n); } return ret; } static const struct file_operations proc_slabstats_operations = { .open = slabstats_open, .read = seq_read, .llseek = seq_lseek, .release = seq_release_private, }; #endif static int __init slab_proc_init(void) { #ifdef CONFIG_DEBUG_SLAB_LEAK proc_create("slab_allocators", 0, NULL, &proc_slabstats_operations); #endif return 0; } module_init(slab_proc_init); #endif /** * ksize - get the actual amount of memory allocated for a given object * @objp: Pointer to the object * * kmalloc may internally round up allocations and return more memory * than requested. ksize() can be used to determine the actual amount of * memory allocated. The caller may use this additional memory, even though * a smaller amount of memory was initially specified with the kmalloc call. * The caller must guarantee that objp points to a valid object previously * allocated with either kmalloc() or kmem_cache_alloc(). The object * must not be freed during the duration of the call. */ size_t ksize(const void *objp) { BUG_ON(!objp); if (unlikely(objp == ZERO_SIZE_PTR)) return 0; return obj_size(virt_to_cache(objp)); }


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