4509 lines
111 KiB
C
4509 lines
111 KiB
C
/*
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* linux/mm/slab.c
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* Written by Mark Hemment, 1996/97.
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* (markhe@nextd.demon.co.uk)
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*
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* kmem_cache_destroy() + some cleanup - 1999 Andrea Arcangeli
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*
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* Major cleanup, different bufctl logic, per-cpu arrays
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* (c) 2000 Manfred Spraul
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*
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* Cleanup, make the head arrays unconditional, preparation for NUMA
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* (c) 2002 Manfred Spraul
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*
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* An implementation of the Slab Allocator as described in outline in;
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* UNIX Internals: The New Frontiers by Uresh Vahalia
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* Pub: Prentice Hall ISBN 0-13-101908-2
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* or with a little more detail in;
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* The Slab Allocator: An Object-Caching Kernel Memory Allocator
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* Jeff Bonwick (Sun Microsystems).
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* Presented at: USENIX Summer 1994 Technical Conference
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*
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* The memory is organized in caches, one cache for each object type.
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* (e.g. inode_cache, dentry_cache, buffer_head, vm_area_struct)
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* Each cache consists out of many slabs (they are small (usually one
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* page long) and always contiguous), and each slab contains multiple
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* initialized objects.
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*
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* This means, that your constructor is used only for newly allocated
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* slabs and you must pass objects with the same initializations to
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* kmem_cache_free.
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*
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* Each cache can only support one memory type (GFP_DMA, GFP_HIGHMEM,
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* normal). If you need a special memory type, then must create a new
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* cache for that memory type.
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*
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* In order to reduce fragmentation, the slabs are sorted in 3 groups:
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* full slabs with 0 free objects
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* partial slabs
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* empty slabs with no allocated objects
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*
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* If partial slabs exist, then new allocations come from these slabs,
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* otherwise from empty slabs or new slabs are allocated.
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*
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* kmem_cache_destroy() CAN CRASH if you try to allocate from the cache
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* during kmem_cache_destroy(). The caller must prevent concurrent allocs.
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*
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* Each cache has a short per-cpu head array, most allocs
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* and frees go into that array, and if that array overflows, then 1/2
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* of the entries in the array are given back into the global cache.
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* The head array is strictly LIFO and should improve the cache hit rates.
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* On SMP, it additionally reduces the spinlock operations.
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*
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* The c_cpuarray may not be read with enabled local interrupts -
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* it's changed with a smp_call_function().
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*
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* SMP synchronization:
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* constructors and destructors are called without any locking.
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* Several members in struct kmem_cache and struct slab never change, they
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* are accessed without any locking.
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* The per-cpu arrays are never accessed from the wrong cpu, no locking,
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* and local interrupts are disabled so slab code is preempt-safe.
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* The non-constant members are protected with a per-cache irq spinlock.
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*
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* Many thanks to Mark Hemment, who wrote another per-cpu slab patch
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* in 2000 - many ideas in the current implementation are derived from
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* his patch.
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*
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* Further notes from the original documentation:
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*
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* 11 April '97. Started multi-threading - markhe
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* The global cache-chain is protected by the mutex 'slab_mutex'.
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* The sem is only needed when accessing/extending the cache-chain, which
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* can never happen inside an interrupt (kmem_cache_create(),
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* kmem_cache_shrink() and kmem_cache_reap()).
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*
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* At present, each engine can be growing a cache. This should be blocked.
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*
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* 15 March 2005. NUMA slab allocator.
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* Shai Fultheim <shai@scalex86.org>.
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* Shobhit Dayal <shobhit@calsoftinc.com>
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* Alok N Kataria <alokk@calsoftinc.com>
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* Christoph Lameter <christoph@lameter.com>
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*
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* Modified the slab allocator to be node aware on NUMA systems.
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* Each node has its own list of partial, free and full slabs.
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* All object allocations for a node occur from node specific slab lists.
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*/
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#include <linux/slab.h>
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#include <linux/mm.h>
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#include <linux/poison.h>
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#include <linux/swap.h>
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#include <linux/cache.h>
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#include <linux/interrupt.h>
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#include <linux/init.h>
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#include <linux/compiler.h>
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#include <linux/cpuset.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <linux/notifier.h>
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#include <linux/kallsyms.h>
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#include <linux/cpu.h>
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#include <linux/sysctl.h>
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#include <linux/module.h>
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#include <linux/rcupdate.h>
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#include <linux/string.h>
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#include <linux/uaccess.h>
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#include <linux/nodemask.h>
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#include <linux/kmemleak.h>
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#include <linux/mempolicy.h>
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#include <linux/mutex.h>
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#include <linux/fault-inject.h>
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#include <linux/rtmutex.h>
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#include <linux/reciprocal_div.h>
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#include <linux/debugobjects.h>
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#include <linux/kmemcheck.h>
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#include <linux/memory.h>
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#include <linux/prefetch.h>
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#include <net/sock.h>
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#include <asm/cacheflush.h>
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#include <asm/tlbflush.h>
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#include <asm/page.h>
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#include <trace/events/kmem.h>
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#include "internal.h"
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#include "slab.h"
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/*
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* DEBUG - 1 for kmem_cache_create() to honour; SLAB_RED_ZONE & SLAB_POISON.
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* 0 for faster, smaller code (especially in the critical paths).
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*
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* STATS - 1 to collect stats for /proc/slabinfo.
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* 0 for faster, smaller code (especially in the critical paths).
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*
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* FORCED_DEBUG - 1 enables SLAB_RED_ZONE and SLAB_POISON (if possible)
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*/
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#ifdef CONFIG_DEBUG_SLAB
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#define DEBUG 1
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#define STATS 1
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#define FORCED_DEBUG 1
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#else
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#define DEBUG 0
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#define STATS 0
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#define FORCED_DEBUG 0
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#endif
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/* Shouldn't this be in a header file somewhere? */
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#define BYTES_PER_WORD sizeof(void *)
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#define REDZONE_ALIGN max(BYTES_PER_WORD, __alignof__(unsigned long long))
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#ifndef ARCH_KMALLOC_FLAGS
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#define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN
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#endif
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#define FREELIST_BYTE_INDEX (((PAGE_SIZE >> BITS_PER_BYTE) \
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<= SLAB_OBJ_MIN_SIZE) ? 1 : 0)
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#if FREELIST_BYTE_INDEX
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typedef unsigned char freelist_idx_t;
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#else
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typedef unsigned short freelist_idx_t;
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#endif
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#define SLAB_OBJ_MAX_NUM ((1 << sizeof(freelist_idx_t) * BITS_PER_BYTE) - 1)
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/*
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* struct array_cache
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*
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* Purpose:
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* - LIFO ordering, to hand out cache-warm objects from _alloc
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* - reduce the number of linked list operations
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* - reduce spinlock operations
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*
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* The limit is stored in the per-cpu structure to reduce the data cache
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* footprint.
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*
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*/
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struct array_cache {
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unsigned int avail;
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unsigned int limit;
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unsigned int batchcount;
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unsigned int touched;
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void *entry[]; /*
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* Must have this definition in here for the proper
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* alignment of array_cache. Also simplifies accessing
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* the entries.
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*/
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};
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struct alien_cache {
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spinlock_t lock;
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struct array_cache ac;
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};
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/*
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* Need this for bootstrapping a per node allocator.
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*/
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#define NUM_INIT_LISTS (2 * MAX_NUMNODES)
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static struct kmem_cache_node __initdata init_kmem_cache_node[NUM_INIT_LISTS];
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#define CACHE_CACHE 0
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#define SIZE_NODE (MAX_NUMNODES)
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static int drain_freelist(struct kmem_cache *cache,
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struct kmem_cache_node *n, int tofree);
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static void free_block(struct kmem_cache *cachep, void **objpp, int len,
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int node, struct list_head *list);
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static void slabs_destroy(struct kmem_cache *cachep, struct list_head *list);
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static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp);
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static void cache_reap(struct work_struct *unused);
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static inline void fixup_objfreelist_debug(struct kmem_cache *cachep,
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void **list);
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static inline void fixup_slab_list(struct kmem_cache *cachep,
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struct kmem_cache_node *n, struct page *page,
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void **list);
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static int slab_early_init = 1;
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#define INDEX_NODE kmalloc_index(sizeof(struct kmem_cache_node))
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static void kmem_cache_node_init(struct kmem_cache_node *parent)
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{
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INIT_LIST_HEAD(&parent->slabs_full);
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INIT_LIST_HEAD(&parent->slabs_partial);
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INIT_LIST_HEAD(&parent->slabs_free);
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parent->shared = NULL;
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parent->alien = NULL;
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parent->colour_next = 0;
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spin_lock_init(&parent->list_lock);
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parent->free_objects = 0;
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parent->free_touched = 0;
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}
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#define MAKE_LIST(cachep, listp, slab, nodeid) \
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do { \
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INIT_LIST_HEAD(listp); \
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list_splice(&get_node(cachep, nodeid)->slab, listp); \
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} while (0)
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#define MAKE_ALL_LISTS(cachep, ptr, nodeid) \
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do { \
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MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \
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MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \
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MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \
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} while (0)
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#define CFLGS_OBJFREELIST_SLAB (0x40000000UL)
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#define CFLGS_OFF_SLAB (0x80000000UL)
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#define OBJFREELIST_SLAB(x) ((x)->flags & CFLGS_OBJFREELIST_SLAB)
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#define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB)
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#define BATCHREFILL_LIMIT 16
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/*
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* Optimization question: fewer reaps means less probability for unnessary
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* cpucache drain/refill cycles.
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*
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* OTOH the cpuarrays can contain lots of objects,
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* which could lock up otherwise freeable slabs.
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*/
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#define REAPTIMEOUT_AC (2*HZ)
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#define REAPTIMEOUT_NODE (4*HZ)
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#if STATS
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#define STATS_INC_ACTIVE(x) ((x)->num_active++)
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#define STATS_DEC_ACTIVE(x) ((x)->num_active--)
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#define STATS_INC_ALLOCED(x) ((x)->num_allocations++)
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#define STATS_INC_GROWN(x) ((x)->grown++)
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#define STATS_ADD_REAPED(x,y) ((x)->reaped += (y))
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#define STATS_SET_HIGH(x) \
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do { \
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if ((x)->num_active > (x)->high_mark) \
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(x)->high_mark = (x)->num_active; \
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} while (0)
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#define STATS_INC_ERR(x) ((x)->errors++)
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#define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++)
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#define STATS_INC_NODEFREES(x) ((x)->node_frees++)
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#define STATS_INC_ACOVERFLOW(x) ((x)->node_overflow++)
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#define STATS_SET_FREEABLE(x, i) \
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do { \
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if ((x)->max_freeable < i) \
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(x)->max_freeable = i; \
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} while (0)
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#define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit)
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#define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss)
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#define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit)
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#define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss)
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#else
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#define STATS_INC_ACTIVE(x) do { } while (0)
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#define STATS_DEC_ACTIVE(x) do { } while (0)
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#define STATS_INC_ALLOCED(x) do { } while (0)
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#define STATS_INC_GROWN(x) do { } while (0)
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#define STATS_ADD_REAPED(x,y) do { (void)(y); } while (0)
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#define STATS_SET_HIGH(x) do { } while (0)
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#define STATS_INC_ERR(x) do { } while (0)
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#define STATS_INC_NODEALLOCS(x) do { } while (0)
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#define STATS_INC_NODEFREES(x) do { } while (0)
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#define STATS_INC_ACOVERFLOW(x) do { } while (0)
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#define STATS_SET_FREEABLE(x, i) do { } while (0)
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#define STATS_INC_ALLOCHIT(x) do { } while (0)
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#define STATS_INC_ALLOCMISS(x) do { } while (0)
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#define STATS_INC_FREEHIT(x) do { } while (0)
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#define STATS_INC_FREEMISS(x) do { } while (0)
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#endif
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#if DEBUG
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/*
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* memory layout of objects:
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* 0 : objp
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* 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that
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* the end of an object is aligned with the end of the real
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* allocation. Catches writes behind the end of the allocation.
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* cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1:
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* redzone word.
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* cachep->obj_offset: The real object.
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* cachep->size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long]
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* cachep->size - 1* BYTES_PER_WORD: last caller address
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* [BYTES_PER_WORD long]
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*/
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static int obj_offset(struct kmem_cache *cachep)
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{
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return cachep->obj_offset;
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}
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static unsigned long long *dbg_redzone1(struct kmem_cache *cachep, void *objp)
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{
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BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
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return (unsigned long long*) (objp + obj_offset(cachep) -
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sizeof(unsigned long long));
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}
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static unsigned long long *dbg_redzone2(struct kmem_cache *cachep, void *objp)
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{
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BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
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if (cachep->flags & SLAB_STORE_USER)
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return (unsigned long long *)(objp + cachep->size -
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sizeof(unsigned long long) -
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REDZONE_ALIGN);
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return (unsigned long long *) (objp + cachep->size -
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sizeof(unsigned long long));
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}
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static void **dbg_userword(struct kmem_cache *cachep, void *objp)
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{
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BUG_ON(!(cachep->flags & SLAB_STORE_USER));
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return (void **)(objp + cachep->size - BYTES_PER_WORD);
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}
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#else
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#define obj_offset(x) 0
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#define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long long *)NULL;})
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#define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long long *)NULL;})
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#define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;})
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#endif
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#ifdef CONFIG_DEBUG_SLAB_LEAK
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static inline bool is_store_user_clean(struct kmem_cache *cachep)
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{
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return atomic_read(&cachep->store_user_clean) == 1;
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}
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static inline void set_store_user_clean(struct kmem_cache *cachep)
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{
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atomic_set(&cachep->store_user_clean, 1);
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}
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static inline void set_store_user_dirty(struct kmem_cache *cachep)
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{
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if (is_store_user_clean(cachep))
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atomic_set(&cachep->store_user_clean, 0);
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}
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#else
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static inline void set_store_user_dirty(struct kmem_cache *cachep) {}
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#endif
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/*
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* Do not go above this order unless 0 objects fit into the slab or
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* overridden on the command line.
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*/
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#define SLAB_MAX_ORDER_HI 1
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#define SLAB_MAX_ORDER_LO 0
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static int slab_max_order = SLAB_MAX_ORDER_LO;
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static bool slab_max_order_set __initdata;
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static inline struct kmem_cache *virt_to_cache(const void *obj)
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{
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struct page *page = virt_to_head_page(obj);
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return page->slab_cache;
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}
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static inline void *index_to_obj(struct kmem_cache *cache, struct page *page,
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unsigned int idx)
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{
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return page->s_mem + cache->size * idx;
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}
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/*
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* We want to avoid an expensive divide : (offset / cache->size)
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* Using the fact that size is a constant for a particular cache,
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* we can replace (offset / cache->size) by
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* reciprocal_divide(offset, cache->reciprocal_buffer_size)
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*/
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static inline unsigned int obj_to_index(const struct kmem_cache *cache,
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const struct page *page, void *obj)
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{
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u32 offset = (obj - page->s_mem);
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return reciprocal_divide(offset, cache->reciprocal_buffer_size);
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}
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#define BOOT_CPUCACHE_ENTRIES 1
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/* internal cache of cache description objs */
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static struct kmem_cache kmem_cache_boot = {
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.batchcount = 1,
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.limit = BOOT_CPUCACHE_ENTRIES,
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.shared = 1,
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.size = sizeof(struct kmem_cache),
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.name = "kmem_cache",
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};
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static DEFINE_PER_CPU(struct delayed_work, slab_reap_work);
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static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep)
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{
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return this_cpu_ptr(cachep->cpu_cache);
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}
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/*
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* Calculate the number of objects and left-over bytes for a given buffer size.
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*/
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static unsigned int cache_estimate(unsigned long gfporder, size_t buffer_size,
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unsigned long flags, size_t *left_over)
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{
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unsigned int num;
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size_t slab_size = PAGE_SIZE << gfporder;
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/*
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* The slab management structure can be either off the slab or
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* on it. For the latter case, the memory allocated for a
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* slab is used for:
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*
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* - @buffer_size bytes for each object
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* - One freelist_idx_t for each object
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*
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* We don't need to consider alignment of freelist because
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* freelist will be at the end of slab page. The objects will be
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* at the correct alignment.
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*
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* If the slab management structure is off the slab, then the
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* alignment will already be calculated into the size. Because
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* the slabs are all pages aligned, the objects will be at the
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* correct alignment when allocated.
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*/
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if (flags & (CFLGS_OBJFREELIST_SLAB | CFLGS_OFF_SLAB)) {
|
|
num = slab_size / buffer_size;
|
|
*left_over = slab_size % buffer_size;
|
|
} else {
|
|
num = slab_size / (buffer_size + sizeof(freelist_idx_t));
|
|
*left_over = slab_size %
|
|
(buffer_size + sizeof(freelist_idx_t));
|
|
}
|
|
|
|
return num;
|
|
}
|
|
|
|
#if DEBUG
|
|
#define slab_error(cachep, msg) __slab_error(__func__, cachep, msg)
|
|
|
|
static void __slab_error(const char *function, struct kmem_cache *cachep,
|
|
char *msg)
|
|
{
|
|
pr_err("slab error in %s(): cache `%s': %s\n",
|
|
function, cachep->name, msg);
|
|
dump_stack();
|
|
add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* 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 __init noaliencache_setup(char *s)
|
|
{
|
|
use_alien_caches = 0;
|
|
return 1;
|
|
}
|
|
__setup("noaliencache", noaliencache_setup);
|
|
|
|
static int __init slab_max_order_setup(char *str)
|
|
{
|
|
get_option(&str, &slab_max_order);
|
|
slab_max_order = slab_max_order < 0 ? 0 :
|
|
min(slab_max_order, MAX_ORDER - 1);
|
|
slab_max_order_set = true;
|
|
|
|
return 1;
|
|
}
|
|
__setup("slab_max_order=", slab_max_order_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, slab_reap_node);
|
|
|
|
static void init_reap_node(int cpu)
|
|
{
|
|
per_cpu(slab_reap_node, cpu) = next_node_in(cpu_to_mem(cpu),
|
|
node_online_map);
|
|
}
|
|
|
|
static void next_reap_node(void)
|
|
{
|
|
int node = __this_cpu_read(slab_reap_node);
|
|
|
|
node = next_node_in(node, node_online_map);
|
|
__this_cpu_write(slab_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 start_cpu_timer(int cpu)
|
|
{
|
|
struct delayed_work *reap_work = &per_cpu(slab_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_DEFERRABLE_WORK(reap_work, cache_reap);
|
|
schedule_delayed_work_on(cpu, reap_work,
|
|
__round_jiffies_relative(HZ, cpu));
|
|
}
|
|
}
|
|
|
|
static void init_arraycache(struct array_cache *ac, int limit, int batch)
|
|
{
|
|
/*
|
|
* The array_cache structures contain pointers to free object.
|
|
* However, when such objects are allocated or transferred to another
|
|
* cache the pointers are not cleared and they could be counted as
|
|
* valid references during a kmemleak scan. Therefore, kmemleak must
|
|
* not scan such objects.
|
|
*/
|
|
kmemleak_no_scan(ac);
|
|
if (ac) {
|
|
ac->avail = 0;
|
|
ac->limit = limit;
|
|
ac->batchcount = batch;
|
|
ac->touched = 0;
|
|
}
|
|
}
|
|
|
|
static struct array_cache *alloc_arraycache(int node, int entries,
|
|
int batchcount, gfp_t gfp)
|
|
{
|
|
size_t memsize = sizeof(void *) * entries + sizeof(struct array_cache);
|
|
struct array_cache *ac = NULL;
|
|
|
|
ac = kmalloc_node(memsize, gfp, node);
|
|
init_arraycache(ac, entries, batchcount);
|
|
return ac;
|
|
}
|
|
|
|
static noinline void cache_free_pfmemalloc(struct kmem_cache *cachep,
|
|
struct page *page, void *objp)
|
|
{
|
|
struct kmem_cache_node *n;
|
|
int page_node;
|
|
LIST_HEAD(list);
|
|
|
|
page_node = page_to_nid(page);
|
|
n = get_node(cachep, page_node);
|
|
|
|
spin_lock(&n->list_lock);
|
|
free_block(cachep, &objp, 1, page_node, &list);
|
|
spin_unlock(&n->list_lock);
|
|
|
|
slabs_destroy(cachep, &list);
|
|
}
|
|
|
|
/*
|
|
* 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 = min3(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;
|
|
return nr;
|
|
}
|
|
|
|
#ifndef CONFIG_NUMA
|
|
|
|
#define drain_alien_cache(cachep, alien) do { } while (0)
|
|
#define reap_alien(cachep, n) do { } while (0)
|
|
|
|
static inline struct alien_cache **alloc_alien_cache(int node,
|
|
int limit, gfp_t gfp)
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
static inline void free_alien_cache(struct alien_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;
|
|
}
|
|
|
|
static inline gfp_t gfp_exact_node(gfp_t flags)
|
|
{
|
|
return flags & ~__GFP_NOFAIL;
|
|
}
|
|
|
|
#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 alien_cache *__alloc_alien_cache(int node, int entries,
|
|
int batch, gfp_t gfp)
|
|
{
|
|
size_t memsize = sizeof(void *) * entries + sizeof(struct alien_cache);
|
|
struct alien_cache *alc = NULL;
|
|
|
|
alc = kmalloc_node(memsize, gfp, node);
|
|
init_arraycache(&alc->ac, entries, batch);
|
|
spin_lock_init(&alc->lock);
|
|
return alc;
|
|
}
|
|
|
|
static struct alien_cache **alloc_alien_cache(int node, int limit, gfp_t gfp)
|
|
{
|
|
struct alien_cache **alc_ptr;
|
|
size_t memsize = sizeof(void *) * nr_node_ids;
|
|
int i;
|
|
|
|
if (limit > 1)
|
|
limit = 12;
|
|
alc_ptr = kzalloc_node(memsize, gfp, node);
|
|
if (!alc_ptr)
|
|
return NULL;
|
|
|
|
for_each_node(i) {
|
|
if (i == node || !node_online(i))
|
|
continue;
|
|
alc_ptr[i] = __alloc_alien_cache(node, limit, 0xbaadf00d, gfp);
|
|
if (!alc_ptr[i]) {
|
|
for (i--; i >= 0; i--)
|
|
kfree(alc_ptr[i]);
|
|
kfree(alc_ptr);
|
|
return NULL;
|
|
}
|
|
}
|
|
return alc_ptr;
|
|
}
|
|
|
|
static void free_alien_cache(struct alien_cache **alc_ptr)
|
|
{
|
|
int i;
|
|
|
|
if (!alc_ptr)
|
|
return;
|
|
for_each_node(i)
|
|
kfree(alc_ptr[i]);
|
|
kfree(alc_ptr);
|
|
}
|
|
|
|
static void __drain_alien_cache(struct kmem_cache *cachep,
|
|
struct array_cache *ac, int node,
|
|
struct list_head *list)
|
|
{
|
|
struct kmem_cache_node *n = get_node(cachep, node);
|
|
|
|
if (ac->avail) {
|
|
spin_lock(&n->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 (n->shared)
|
|
transfer_objects(n->shared, ac, ac->limit);
|
|
|
|
free_block(cachep, ac->entry, ac->avail, node, list);
|
|
ac->avail = 0;
|
|
spin_unlock(&n->list_lock);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Called from cache_reap() to regularly drain alien caches round robin.
|
|
*/
|
|
static void reap_alien(struct kmem_cache *cachep, struct kmem_cache_node *n)
|
|
{
|
|
int node = __this_cpu_read(slab_reap_node);
|
|
|
|
if (n->alien) {
|
|
struct alien_cache *alc = n->alien[node];
|
|
struct array_cache *ac;
|
|
|
|
if (alc) {
|
|
ac = &alc->ac;
|
|
if (ac->avail && spin_trylock_irq(&alc->lock)) {
|
|
LIST_HEAD(list);
|
|
|
|
__drain_alien_cache(cachep, ac, node, &list);
|
|
spin_unlock_irq(&alc->lock);
|
|
slabs_destroy(cachep, &list);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static void drain_alien_cache(struct kmem_cache *cachep,
|
|
struct alien_cache **alien)
|
|
{
|
|
int i = 0;
|
|
struct alien_cache *alc;
|
|
struct array_cache *ac;
|
|
unsigned long flags;
|
|
|
|
for_each_online_node(i) {
|
|
alc = alien[i];
|
|
if (alc) {
|
|
LIST_HEAD(list);
|
|
|
|
ac = &alc->ac;
|
|
spin_lock_irqsave(&alc->lock, flags);
|
|
__drain_alien_cache(cachep, ac, i, &list);
|
|
spin_unlock_irqrestore(&alc->lock, flags);
|
|
slabs_destroy(cachep, &list);
|
|
}
|
|
}
|
|
}
|
|
|
|
static int __cache_free_alien(struct kmem_cache *cachep, void *objp,
|
|
int node, int page_node)
|
|
{
|
|
struct kmem_cache_node *n;
|
|
struct alien_cache *alien = NULL;
|
|
struct array_cache *ac;
|
|
LIST_HEAD(list);
|
|
|
|
n = get_node(cachep, node);
|
|
STATS_INC_NODEFREES(cachep);
|
|
if (n->alien && n->alien[page_node]) {
|
|
alien = n->alien[page_node];
|
|
ac = &alien->ac;
|
|
spin_lock(&alien->lock);
|
|
if (unlikely(ac->avail == ac->limit)) {
|
|
STATS_INC_ACOVERFLOW(cachep);
|
|
__drain_alien_cache(cachep, ac, page_node, &list);
|
|
}
|
|
ac->entry[ac->avail++] = objp;
|
|
spin_unlock(&alien->lock);
|
|
slabs_destroy(cachep, &list);
|
|
} else {
|
|
n = get_node(cachep, page_node);
|
|
spin_lock(&n->list_lock);
|
|
free_block(cachep, &objp, 1, page_node, &list);
|
|
spin_unlock(&n->list_lock);
|
|
slabs_destroy(cachep, &list);
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
|
|
{
|
|
int page_node = page_to_nid(virt_to_page(objp));
|
|
int node = numa_mem_id();
|
|
/*
|
|
* Make sure we are not freeing a object from another node to the array
|
|
* cache on this cpu.
|
|
*/
|
|
if (likely(node == page_node))
|
|
return 0;
|
|
|
|
return __cache_free_alien(cachep, objp, node, page_node);
|
|
}
|
|
|
|
/*
|
|
* Construct gfp mask to allocate from a specific node but do not reclaim or
|
|
* warn about failures.
|
|
*/
|
|
static inline gfp_t gfp_exact_node(gfp_t flags)
|
|
{
|
|
return (flags | __GFP_THISNODE | __GFP_NOWARN) & ~(__GFP_RECLAIM|__GFP_NOFAIL);
|
|
}
|
|
#endif
|
|
|
|
static int init_cache_node(struct kmem_cache *cachep, int node, gfp_t gfp)
|
|
{
|
|
struct kmem_cache_node *n;
|
|
|
|
/*
|
|
* Set up the kmem_cache_node for cpu before we can
|
|
* begin anything. Make sure some other cpu on this
|
|
* node has not already allocated this
|
|
*/
|
|
n = get_node(cachep, node);
|
|
if (n) {
|
|
spin_lock_irq(&n->list_lock);
|
|
n->free_limit = (1 + nr_cpus_node(node)) * cachep->batchcount +
|
|
cachep->num;
|
|
spin_unlock_irq(&n->list_lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
n = kmalloc_node(sizeof(struct kmem_cache_node), gfp, node);
|
|
if (!n)
|
|
return -ENOMEM;
|
|
|
|
kmem_cache_node_init(n);
|
|
n->next_reap = jiffies + REAPTIMEOUT_NODE +
|
|
((unsigned long)cachep) % REAPTIMEOUT_NODE;
|
|
|
|
n->free_limit =
|
|
(1 + nr_cpus_node(node)) * cachep->batchcount + cachep->num;
|
|
|
|
/*
|
|
* The kmem_cache_nodes don't come and go as CPUs
|
|
* come and go. slab_mutex is sufficient
|
|
* protection here.
|
|
*/
|
|
cachep->node[node] = n;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Allocates and initializes node for a node on each slab cache, used for
|
|
* either memory or cpu hotplug. If memory is being hot-added, the kmem_cache_node
|
|
* will be allocated off-node since memory is not yet online for the new node.
|
|
* When hotplugging memory or a cpu, existing node are not replaced if
|
|
* already in use.
|
|
*
|
|
* Must hold slab_mutex.
|
|
*/
|
|
static int init_cache_node_node(int node)
|
|
{
|
|
int ret;
|
|
struct kmem_cache *cachep;
|
|
|
|
list_for_each_entry(cachep, &slab_caches, list) {
|
|
ret = init_cache_node(cachep, node, GFP_KERNEL);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int setup_kmem_cache_node(struct kmem_cache *cachep,
|
|
int node, gfp_t gfp, bool force_change)
|
|
{
|
|
int ret = -ENOMEM;
|
|
struct kmem_cache_node *n;
|
|
struct array_cache *old_shared = NULL;
|
|
struct array_cache *new_shared = NULL;
|
|
struct alien_cache **new_alien = NULL;
|
|
LIST_HEAD(list);
|
|
|
|
if (use_alien_caches) {
|
|
new_alien = alloc_alien_cache(node, cachep->limit, gfp);
|
|
if (!new_alien)
|
|
goto fail;
|
|
}
|
|
|
|
if (cachep->shared) {
|
|
new_shared = alloc_arraycache(node,
|
|
cachep->shared * cachep->batchcount, 0xbaadf00d, gfp);
|
|
if (!new_shared)
|
|
goto fail;
|
|
}
|
|
|
|
ret = init_cache_node(cachep, node, gfp);
|
|
if (ret)
|
|
goto fail;
|
|
|
|
n = get_node(cachep, node);
|
|
spin_lock_irq(&n->list_lock);
|
|
if (n->shared && force_change) {
|
|
free_block(cachep, n->shared->entry,
|
|
n->shared->avail, node, &list);
|
|
n->shared->avail = 0;
|
|
}
|
|
|
|
if (!n->shared || force_change) {
|
|
old_shared = n->shared;
|
|
n->shared = new_shared;
|
|
new_shared = NULL;
|
|
}
|
|
|
|
if (!n->alien) {
|
|
n->alien = new_alien;
|
|
new_alien = NULL;
|
|
}
|
|
|
|
spin_unlock_irq(&n->list_lock);
|
|
slabs_destroy(cachep, &list);
|
|
|
|
/*
|
|
* To protect lockless access to n->shared during irq disabled context.
|
|
* If n->shared isn't NULL in irq disabled context, accessing to it is
|
|
* guaranteed to be valid until irq is re-enabled, because it will be
|
|
* freed after synchronize_sched().
|
|
*/
|
|
if (force_change)
|
|
synchronize_sched();
|
|
|
|
fail:
|
|
kfree(old_shared);
|
|
kfree(new_shared);
|
|
free_alien_cache(new_alien);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void cpuup_canceled(long cpu)
|
|
{
|
|
struct kmem_cache *cachep;
|
|
struct kmem_cache_node *n = NULL;
|
|
int node = cpu_to_mem(cpu);
|
|
const struct cpumask *mask = cpumask_of_node(node);
|
|
|
|
list_for_each_entry(cachep, &slab_caches, list) {
|
|
struct array_cache *nc;
|
|
struct array_cache *shared;
|
|
struct alien_cache **alien;
|
|
LIST_HEAD(list);
|
|
|
|
n = get_node(cachep, node);
|
|
if (!n)
|
|
continue;
|
|
|
|
spin_lock_irq(&n->list_lock);
|
|
|
|
/* Free limit for this kmem_cache_node */
|
|
n->free_limit -= cachep->batchcount;
|
|
|
|
/* cpu is dead; no one can alloc from it. */
|
|
nc = per_cpu_ptr(cachep->cpu_cache, cpu);
|
|
if (nc) {
|
|
free_block(cachep, nc->entry, nc->avail, node, &list);
|
|
nc->avail = 0;
|
|
}
|
|
|
|
if (!cpumask_empty(mask)) {
|
|
spin_unlock_irq(&n->list_lock);
|
|
goto free_slab;
|
|
}
|
|
|
|
shared = n->shared;
|
|
if (shared) {
|
|
free_block(cachep, shared->entry,
|
|
shared->avail, node, &list);
|
|
n->shared = NULL;
|
|
}
|
|
|
|
alien = n->alien;
|
|
n->alien = NULL;
|
|
|
|
spin_unlock_irq(&n->list_lock);
|
|
|
|
kfree(shared);
|
|
if (alien) {
|
|
drain_alien_cache(cachep, alien);
|
|
free_alien_cache(alien);
|
|
}
|
|
|
|
free_slab:
|
|
slabs_destroy(cachep, &list);
|
|
}
|
|
/*
|
|
* 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, &slab_caches, list) {
|
|
n = get_node(cachep, node);
|
|
if (!n)
|
|
continue;
|
|
drain_freelist(cachep, n, INT_MAX);
|
|
}
|
|
}
|
|
|
|
static int cpuup_prepare(long cpu)
|
|
{
|
|
struct kmem_cache *cachep;
|
|
int node = cpu_to_mem(cpu);
|
|
int err;
|
|
|
|
/*
|
|
* 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_cache_node and not this cpu's kmem_cache_node
|
|
*/
|
|
err = init_cache_node_node(node);
|
|
if (err < 0)
|
|
goto bad;
|
|
|
|
/*
|
|
* Now we can go ahead with allocating the shared arrays and
|
|
* array caches
|
|
*/
|
|
list_for_each_entry(cachep, &slab_caches, list) {
|
|
err = setup_kmem_cache_node(cachep, node, GFP_KERNEL, false);
|
|
if (err)
|
|
goto bad;
|
|
}
|
|
|
|
return 0;
|
|
bad:
|
|
cpuup_canceled(cpu);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static int 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(&slab_mutex);
|
|
err = cpuup_prepare(cpu);
|
|
mutex_unlock(&slab_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 slab_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_delayed_work_sync(&per_cpu(slab_reap_work, cpu));
|
|
/* Now the cache_reaper is guaranteed to be not running. */
|
|
per_cpu(slab_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_cache_node 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 node
|
|
* 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(&slab_mutex);
|
|
cpuup_canceled(cpu);
|
|
mutex_unlock(&slab_mutex);
|
|
break;
|
|
}
|
|
return notifier_from_errno(err);
|
|
}
|
|
|
|
static struct notifier_block cpucache_notifier = {
|
|
&cpuup_callback, NULL, 0
|
|
};
|
|
|
|
#if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG)
|
|
/*
|
|
* Drains freelist for a node on each slab cache, used for memory hot-remove.
|
|
* Returns -EBUSY if all objects cannot be drained so that the node is not
|
|
* removed.
|
|
*
|
|
* Must hold slab_mutex.
|
|
*/
|
|
static int __meminit drain_cache_node_node(int node)
|
|
{
|
|
struct kmem_cache *cachep;
|
|
int ret = 0;
|
|
|
|
list_for_each_entry(cachep, &slab_caches, list) {
|
|
struct kmem_cache_node *n;
|
|
|
|
n = get_node(cachep, node);
|
|
if (!n)
|
|
continue;
|
|
|
|
drain_freelist(cachep, n, INT_MAX);
|
|
|
|
if (!list_empty(&n->slabs_full) ||
|
|
!list_empty(&n->slabs_partial)) {
|
|
ret = -EBUSY;
|
|
break;
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static int __meminit slab_memory_callback(struct notifier_block *self,
|
|
unsigned long action, void *arg)
|
|
{
|
|
struct memory_notify *mnb = arg;
|
|
int ret = 0;
|
|
int nid;
|
|
|
|
nid = mnb->status_change_nid;
|
|
if (nid < 0)
|
|
goto out;
|
|
|
|
switch (action) {
|
|
case MEM_GOING_ONLINE:
|
|
mutex_lock(&slab_mutex);
|
|
ret = init_cache_node_node(nid);
|
|
mutex_unlock(&slab_mutex);
|
|
break;
|
|
case MEM_GOING_OFFLINE:
|
|
mutex_lock(&slab_mutex);
|
|
ret = drain_cache_node_node(nid);
|
|
mutex_unlock(&slab_mutex);
|
|
break;
|
|
case MEM_ONLINE:
|
|
case MEM_OFFLINE:
|
|
case MEM_CANCEL_ONLINE:
|
|
case MEM_CANCEL_OFFLINE:
|
|
break;
|
|
}
|
|
out:
|
|
return notifier_from_errno(ret);
|
|
}
|
|
#endif /* CONFIG_NUMA && CONFIG_MEMORY_HOTPLUG */
|
|
|
|
/*
|
|
* swap the static kmem_cache_node with kmalloced memory
|
|
*/
|
|
static void __init init_list(struct kmem_cache *cachep, struct kmem_cache_node *list,
|
|
int nodeid)
|
|
{
|
|
struct kmem_cache_node *ptr;
|
|
|
|
ptr = kmalloc_node(sizeof(struct kmem_cache_node), GFP_NOWAIT, nodeid);
|
|
BUG_ON(!ptr);
|
|
|
|
memcpy(ptr, list, sizeof(struct kmem_cache_node));
|
|
/*
|
|
* Do not assume that spinlocks can be initialized via memcpy:
|
|
*/
|
|
spin_lock_init(&ptr->list_lock);
|
|
|
|
MAKE_ALL_LISTS(cachep, ptr, nodeid);
|
|
cachep->node[nodeid] = ptr;
|
|
}
|
|
|
|
/*
|
|
* For setting up all the kmem_cache_node for cache whose buffer_size is same as
|
|
* size of kmem_cache_node.
|
|
*/
|
|
static void __init set_up_node(struct kmem_cache *cachep, int index)
|
|
{
|
|
int node;
|
|
|
|
for_each_online_node(node) {
|
|
cachep->node[node] = &init_kmem_cache_node[index + node];
|
|
cachep->node[node]->next_reap = jiffies +
|
|
REAPTIMEOUT_NODE +
|
|
((unsigned long)cachep) % REAPTIMEOUT_NODE;
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_SLAB_FREELIST_RANDOM
|
|
static void freelist_randomize(struct rnd_state *state, freelist_idx_t *list,
|
|
size_t count)
|
|
{
|
|
size_t i;
|
|
unsigned int rand;
|
|
|
|
for (i = 0; i < count; i++)
|
|
list[i] = i;
|
|
|
|
/* Fisher-Yates shuffle */
|
|
for (i = count - 1; i > 0; i--) {
|
|
rand = prandom_u32_state(state);
|
|
rand %= (i + 1);
|
|
swap(list[i], list[rand]);
|
|
}
|
|
}
|
|
|
|
/* Create a random sequence per cache */
|
|
static int cache_random_seq_create(struct kmem_cache *cachep, gfp_t gfp)
|
|
{
|
|
unsigned int seed, count = cachep->num;
|
|
struct rnd_state state;
|
|
|
|
if (count < 2)
|
|
return 0;
|
|
|
|
/* If it fails, we will just use the global lists */
|
|
cachep->random_seq = kcalloc(count, sizeof(freelist_idx_t), gfp);
|
|
if (!cachep->random_seq)
|
|
return -ENOMEM;
|
|
|
|
/* Get best entropy at this stage */
|
|
get_random_bytes_arch(&seed, sizeof(seed));
|
|
prandom_seed_state(&state, seed);
|
|
|
|
freelist_randomize(&state, cachep->random_seq, count);
|
|
return 0;
|
|
}
|
|
|
|
/* Destroy the per-cache random freelist sequence */
|
|
static void cache_random_seq_destroy(struct kmem_cache *cachep)
|
|
{
|
|
kfree(cachep->random_seq);
|
|
cachep->random_seq = NULL;
|
|
}
|
|
#else
|
|
static inline int cache_random_seq_create(struct kmem_cache *cachep, gfp_t gfp)
|
|
{
|
|
return 0;
|
|
}
|
|
static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { }
|
|
#endif /* CONFIG_SLAB_FREELIST_RANDOM */
|
|
|
|
|
|
/*
|
|
* Initialisation. Called after the page allocator have been initialised and
|
|
* before smp_init().
|
|
*/
|
|
void __init kmem_cache_init(void)
|
|
{
|
|
int i;
|
|
|
|
BUILD_BUG_ON(sizeof(((struct page *)NULL)->lru) <
|
|
sizeof(struct rcu_head));
|
|
kmem_cache = &kmem_cache_boot;
|
|
|
|
if (!IS_ENABLED(CONFIG_NUMA) || num_possible_nodes() == 1)
|
|
use_alien_caches = 0;
|
|
|
|
for (i = 0; i < NUM_INIT_LISTS; i++)
|
|
kmem_cache_node_init(&init_kmem_cache_node[i]);
|
|
|
|
/*
|
|
* Fragmentation resistance on low memory - only use bigger
|
|
* page orders on machines with more than 32MB of memory if
|
|
* not overridden on the command line.
|
|
*/
|
|
if (!slab_max_order_set && totalram_pages > (32 << 20) >> PAGE_SHIFT)
|
|
slab_max_order = SLAB_MAX_ORDER_HI;
|
|
|
|
/* Bootstrap is tricky, because several objects are allocated
|
|
* from caches that do not exist yet:
|
|
* 1) initialize the kmem_cache cache: it contains the struct
|
|
* kmem_cache structures of all caches, except kmem_cache itself:
|
|
* kmem_cache is statically allocated.
|
|
* Initially an __init data area is used for the head array and the
|
|
* kmem_cache_node 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 kmem_cache and the first
|
|
* kmalloc cache with kmalloc allocated arrays.
|
|
* 5) Replace the __init data for kmem_cache_node for kmem_cache and
|
|
* the other cache's with kmalloc allocated memory.
|
|
* 6) Resize the head arrays of the kmalloc caches to their final sizes.
|
|
*/
|
|
|
|
/* 1) create the kmem_cache */
|
|
|
|
/*
|
|
* struct kmem_cache size depends on nr_node_ids & nr_cpu_ids
|
|
*/
|
|
create_boot_cache(kmem_cache, "kmem_cache",
|
|
offsetof(struct kmem_cache, node) +
|
|
nr_node_ids * sizeof(struct kmem_cache_node *),
|
|
SLAB_HWCACHE_ALIGN);
|
|
list_add(&kmem_cache->list, &slab_caches);
|
|
slab_state = PARTIAL;
|
|
|
|
/*
|
|
* Initialize the caches that provide memory for the kmem_cache_node
|
|
* structures first. Without this, further allocations will bug.
|
|
*/
|
|
kmalloc_caches[INDEX_NODE] = create_kmalloc_cache("kmalloc-node",
|
|
kmalloc_size(INDEX_NODE), ARCH_KMALLOC_FLAGS);
|
|
slab_state = PARTIAL_NODE;
|
|
setup_kmalloc_cache_index_table();
|
|
|
|
slab_early_init = 0;
|
|
|
|
/* 5) Replace the bootstrap kmem_cache_node */
|
|
{
|
|
int nid;
|
|
|
|
for_each_online_node(nid) {
|
|
init_list(kmem_cache, &init_kmem_cache_node[CACHE_CACHE + nid], nid);
|
|
|
|
init_list(kmalloc_caches[INDEX_NODE],
|
|
&init_kmem_cache_node[SIZE_NODE + nid], nid);
|
|
}
|
|
}
|
|
|
|
create_kmalloc_caches(ARCH_KMALLOC_FLAGS);
|
|
}
|
|
|
|
void __init kmem_cache_init_late(void)
|
|
{
|
|
struct kmem_cache *cachep;
|
|
|
|
slab_state = UP;
|
|
|
|
/* 6) resize the head arrays to their final sizes */
|
|
mutex_lock(&slab_mutex);
|
|
list_for_each_entry(cachep, &slab_caches, list)
|
|
if (enable_cpucache(cachep, GFP_NOWAIT))
|
|
BUG();
|
|
mutex_unlock(&slab_mutex);
|
|
|
|
/* Done! */
|
|
slab_state = FULL;
|
|
|
|
/*
|
|
* Register a cpu startup notifier callback that initializes
|
|
* cpu_cache_get for all new cpus
|
|
*/
|
|
register_cpu_notifier(&cpucache_notifier);
|
|
|
|
#ifdef CONFIG_NUMA
|
|
/*
|
|
* Register a memory hotplug callback that initializes and frees
|
|
* node.
|
|
*/
|
|
hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI);
|
|
#endif
|
|
|
|
/*
|
|
* 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);
|
|
|
|
/* Done! */
|
|
slab_state = FULL;
|
|
return 0;
|
|
}
|
|
__initcall(cpucache_init);
|
|
|
|
static noinline void
|
|
slab_out_of_memory(struct kmem_cache *cachep, gfp_t gfpflags, int nodeid)
|
|
{
|
|
#if DEBUG
|
|
struct kmem_cache_node *n;
|
|
struct page *page;
|
|
unsigned long flags;
|
|
int node;
|
|
static DEFINE_RATELIMIT_STATE(slab_oom_rs, DEFAULT_RATELIMIT_INTERVAL,
|
|
DEFAULT_RATELIMIT_BURST);
|
|
|
|
if ((gfpflags & __GFP_NOWARN) || !__ratelimit(&slab_oom_rs))
|
|
return;
|
|
|
|
pr_warn("SLAB: Unable to allocate memory on node %d, gfp=%#x(%pGg)\n",
|
|
nodeid, gfpflags, &gfpflags);
|
|
pr_warn(" cache: %s, object size: %d, order: %d\n",
|
|
cachep->name, cachep->size, cachep->gfporder);
|
|
|
|
for_each_kmem_cache_node(cachep, node, n) {
|
|
unsigned long active_objs = 0, num_objs = 0, free_objects = 0;
|
|
unsigned long active_slabs = 0, num_slabs = 0;
|
|
|
|
spin_lock_irqsave(&n->list_lock, flags);
|
|
list_for_each_entry(page, &n->slabs_full, lru) {
|
|
active_objs += cachep->num;
|
|
active_slabs++;
|
|
}
|
|
list_for_each_entry(page, &n->slabs_partial, lru) {
|
|
active_objs += page->active;
|
|
active_slabs++;
|
|
}
|
|
list_for_each_entry(page, &n->slabs_free, lru)
|
|
num_slabs++;
|
|
|
|
free_objects += n->free_objects;
|
|
spin_unlock_irqrestore(&n->list_lock, flags);
|
|
|
|
num_slabs += active_slabs;
|
|
num_objs = num_slabs * cachep->num;
|
|
pr_warn(" node %d: slabs: %ld/%ld, objs: %ld/%ld, free: %ld\n",
|
|
node, active_slabs, num_slabs, active_objs, num_objs,
|
|
free_objects);
|
|
}
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Interface to system's page allocator. No need to hold the
|
|
* kmem_cache_node ->list_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 struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
|
|
int nodeid)
|
|
{
|
|
struct page *page;
|
|
int nr_pages;
|
|
|
|
flags |= cachep->allocflags;
|
|
if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
|
|
flags |= __GFP_RECLAIMABLE;
|
|
|
|
page = __alloc_pages_node(nodeid, flags | __GFP_NOTRACK, cachep->gfporder);
|
|
if (!page) {
|
|
slab_out_of_memory(cachep, flags, nodeid);
|
|
return NULL;
|
|
}
|
|
|
|
if (memcg_charge_slab(page, flags, cachep->gfporder, cachep)) {
|
|
__free_pages(page, cachep->gfporder);
|
|
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);
|
|
|
|
__SetPageSlab(page);
|
|
/* Record if ALLOC_NO_WATERMARKS was set when allocating the slab */
|
|
if (sk_memalloc_socks() && page_is_pfmemalloc(page))
|
|
SetPageSlabPfmemalloc(page);
|
|
|
|
if (kmemcheck_enabled && !(cachep->flags & SLAB_NOTRACK)) {
|
|
kmemcheck_alloc_shadow(page, cachep->gfporder, flags, nodeid);
|
|
|
|
if (cachep->ctor)
|
|
kmemcheck_mark_uninitialized_pages(page, nr_pages);
|
|
else
|
|
kmemcheck_mark_unallocated_pages(page, nr_pages);
|
|
}
|
|
|
|
return page;
|
|
}
|
|
|
|
/*
|
|
* Interface to system's page release.
|
|
*/
|
|
static void kmem_freepages(struct kmem_cache *cachep, struct page *page)
|
|
{
|
|
int order = cachep->gfporder;
|
|
unsigned long nr_freed = (1 << order);
|
|
|
|
kmemcheck_free_shadow(page, order);
|
|
|
|
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);
|
|
|
|
BUG_ON(!PageSlab(page));
|
|
__ClearPageSlabPfmemalloc(page);
|
|
__ClearPageSlab(page);
|
|
page_mapcount_reset(page);
|
|
page->mapping = NULL;
|
|
|
|
if (current->reclaim_state)
|
|
current->reclaim_state->reclaimed_slab += nr_freed;
|
|
memcg_uncharge_slab(page, order, cachep);
|
|
__free_pages(page, order);
|
|
}
|
|
|
|
static void kmem_rcu_free(struct rcu_head *head)
|
|
{
|
|
struct kmem_cache *cachep;
|
|
struct page *page;
|
|
|
|
page = container_of(head, struct page, rcu_head);
|
|
cachep = page->slab_cache;
|
|
|
|
kmem_freepages(cachep, page);
|
|
}
|
|
|
|
#if DEBUG
|
|
static bool is_debug_pagealloc_cache(struct kmem_cache *cachep)
|
|
{
|
|
if (debug_pagealloc_enabled() && OFF_SLAB(cachep) &&
|
|
(cachep->size % PAGE_SIZE) == 0)
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
#ifdef CONFIG_DEBUG_PAGEALLOC
|
|
static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr,
|
|
unsigned long caller)
|
|
{
|
|
int size = cachep->object_size;
|
|
|
|
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;
|
|
}
|
|
|
|
static void slab_kernel_map(struct kmem_cache *cachep, void *objp,
|
|
int map, unsigned long caller)
|
|
{
|
|
if (!is_debug_pagealloc_cache(cachep))
|
|
return;
|
|
|
|
if (caller)
|
|
store_stackinfo(cachep, objp, caller);
|
|
|
|
kernel_map_pages(virt_to_page(objp), cachep->size / PAGE_SIZE, map);
|
|
}
|
|
|
|
#else
|
|
static inline void slab_kernel_map(struct kmem_cache *cachep, void *objp,
|
|
int map, unsigned long caller) {}
|
|
|
|
#endif
|
|
|
|
static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val)
|
|
{
|
|
int size = cachep->object_size;
|
|
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;
|
|
|
|
pr_err("%03x: ", offset);
|
|
for (i = 0; i < limit; i++) {
|
|
if (data[offset + i] != POISON_FREE) {
|
|
error = data[offset + i];
|
|
bad_count++;
|
|
}
|
|
}
|
|
print_hex_dump(KERN_CONT, "", 0, 16, 1,
|
|
&data[offset], limit, 1);
|
|
|
|
if (bad_count == 1) {
|
|
error ^= POISON_FREE;
|
|
if (!(error & (error - 1))) {
|
|
pr_err("Single bit error detected. Probably bad RAM.\n");
|
|
#ifdef CONFIG_X86
|
|
pr_err("Run memtest86+ or a similar memory test tool.\n");
|
|
#else
|
|
pr_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) {
|
|
pr_err("Redzone: 0x%llx/0x%llx\n",
|
|
*dbg_redzone1(cachep, objp),
|
|
*dbg_redzone2(cachep, objp));
|
|
}
|
|
|
|
if (cachep->flags & SLAB_STORE_USER) {
|
|
pr_err("Last user: [<%p>](%pSR)\n",
|
|
*dbg_userword(cachep, objp),
|
|
*dbg_userword(cachep, objp));
|
|
}
|
|
realobj = (char *)objp + obj_offset(cachep);
|
|
size = cachep->object_size;
|
|
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;
|
|
|
|
if (is_debug_pagealloc_cache(cachep))
|
|
return;
|
|
|
|
realobj = (char *)objp + obj_offset(cachep);
|
|
size = cachep->object_size;
|
|
|
|
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) {
|
|
pr_err("Slab corruption (%s): %s start=%p, len=%d\n",
|
|
print_tainted(), 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 page *page = virt_to_head_page(objp);
|
|
unsigned int objnr;
|
|
|
|
objnr = obj_to_index(cachep, page, objp);
|
|
if (objnr) {
|
|
objp = index_to_obj(cachep, page, objnr - 1);
|
|
realobj = (char *)objp + obj_offset(cachep);
|
|
pr_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, page, objnr + 1);
|
|
realobj = (char *)objp + obj_offset(cachep);
|
|
pr_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 page *page)
|
|
{
|
|
int i;
|
|
|
|
if (OBJFREELIST_SLAB(cachep) && cachep->flags & SLAB_POISON) {
|
|
poison_obj(cachep, page->freelist - obj_offset(cachep),
|
|
POISON_FREE);
|
|
}
|
|
|
|
for (i = 0; i < cachep->num; i++) {
|
|
void *objp = index_to_obj(cachep, page, i);
|
|
|
|
if (cachep->flags & SLAB_POISON) {
|
|
check_poison_obj(cachep, objp);
|
|
slab_kernel_map(cachep, objp, 1, 0);
|
|
}
|
|
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 page *page)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
* slab_destroy - destroy and release all objects in a slab
|
|
* @cachep: cache pointer being destroyed
|
|
* @page: page pointer being destroyed
|
|
*
|
|
* Destroy all the objs in a slab page, and release the mem back to the system.
|
|
* Before calling the slab page must have been unlinked from the cache. The
|
|
* kmem_cache_node ->list_lock is not held/needed.
|
|
*/
|
|
static void slab_destroy(struct kmem_cache *cachep, struct page *page)
|
|
{
|
|
void *freelist;
|
|
|
|
freelist = page->freelist;
|
|
slab_destroy_debugcheck(cachep, page);
|
|
if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU))
|
|
call_rcu(&page->rcu_head, kmem_rcu_free);
|
|
else
|
|
kmem_freepages(cachep, page);
|
|
|
|
/*
|
|
* From now on, we don't use freelist
|
|
* although actual page can be freed in rcu context
|
|
*/
|
|
if (OFF_SLAB(cachep))
|
|
kmem_cache_free(cachep->freelist_cache, freelist);
|
|
}
|
|
|
|
static void slabs_destroy(struct kmem_cache *cachep, struct list_head *list)
|
|
{
|
|
struct page *page, *n;
|
|
|
|
list_for_each_entry_safe(page, n, list, lru) {
|
|
list_del(&page->lru);
|
|
slab_destroy(cachep, page);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* 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.
|
|
* @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, unsigned long flags)
|
|
{
|
|
size_t left_over = 0;
|
|
int gfporder;
|
|
|
|
for (gfporder = 0; gfporder <= KMALLOC_MAX_ORDER; gfporder++) {
|
|
unsigned int num;
|
|
size_t remainder;
|
|
|
|
num = cache_estimate(gfporder, size, flags, &remainder);
|
|
if (!num)
|
|
continue;
|
|
|
|
/* Can't handle number of objects more than SLAB_OBJ_MAX_NUM */
|
|
if (num > SLAB_OBJ_MAX_NUM)
|
|
break;
|
|
|
|
if (flags & CFLGS_OFF_SLAB) {
|
|
struct kmem_cache *freelist_cache;
|
|
size_t freelist_size;
|
|
|
|
freelist_size = num * sizeof(freelist_idx_t);
|
|
freelist_cache = kmalloc_slab(freelist_size, 0u);
|
|
if (!freelist_cache)
|
|
continue;
|
|
|
|
/*
|
|
* Needed to avoid possible looping condition
|
|
* in cache_grow_begin()
|
|
*/
|
|
if (OFF_SLAB(freelist_cache))
|
|
continue;
|
|
|
|
/* check if off slab has enough benefit */
|
|
if (freelist_cache->size > cachep->size / 2)
|
|
continue;
|
|
}
|
|
|
|
/* 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_max_order)
|
|
break;
|
|
|
|
/*
|
|
* Acceptable internal fragmentation?
|
|
*/
|
|
if (left_over * 8 <= (PAGE_SIZE << gfporder))
|
|
break;
|
|
}
|
|
return left_over;
|
|
}
|
|
|
|
static struct array_cache __percpu *alloc_kmem_cache_cpus(
|
|
struct kmem_cache *cachep, int entries, int batchcount)
|
|
{
|
|
int cpu;
|
|
size_t size;
|
|
struct array_cache __percpu *cpu_cache;
|
|
|
|
size = sizeof(void *) * entries + sizeof(struct array_cache);
|
|
cpu_cache = __alloc_percpu(size, sizeof(void *));
|
|
|
|
if (!cpu_cache)
|
|
return NULL;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
init_arraycache(per_cpu_ptr(cpu_cache, cpu),
|
|
entries, batchcount);
|
|
}
|
|
|
|
return cpu_cache;
|
|
}
|
|
|
|
static int __init_refok setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp)
|
|
{
|
|
if (slab_state >= FULL)
|
|
return enable_cpucache(cachep, gfp);
|
|
|
|
cachep->cpu_cache = alloc_kmem_cache_cpus(cachep, 1, 1);
|
|
if (!cachep->cpu_cache)
|
|
return 1;
|
|
|
|
if (slab_state == DOWN) {
|
|
/* Creation of first cache (kmem_cache). */
|
|
set_up_node(kmem_cache, CACHE_CACHE);
|
|
} else if (slab_state == PARTIAL) {
|
|
/* For kmem_cache_node */
|
|
set_up_node(cachep, SIZE_NODE);
|
|
} else {
|
|
int node;
|
|
|
|
for_each_online_node(node) {
|
|
cachep->node[node] = kmalloc_node(
|
|
sizeof(struct kmem_cache_node), gfp, node);
|
|
BUG_ON(!cachep->node[node]);
|
|
kmem_cache_node_init(cachep->node[node]);
|
|
}
|
|
}
|
|
|
|
cachep->node[numa_mem_id()]->next_reap =
|
|
jiffies + REAPTIMEOUT_NODE +
|
|
((unsigned long)cachep) % REAPTIMEOUT_NODE;
|
|
|
|
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;
|
|
}
|
|
|
|
unsigned long kmem_cache_flags(unsigned long object_size,
|
|
unsigned long flags, const char *name,
|
|
void (*ctor)(void *))
|
|
{
|
|
return flags;
|
|
}
|
|
|
|
struct kmem_cache *
|
|
__kmem_cache_alias(const char *name, size_t size, size_t align,
|
|
unsigned long flags, void (*ctor)(void *))
|
|
{
|
|
struct kmem_cache *cachep;
|
|
|
|
cachep = find_mergeable(size, align, flags, name, ctor);
|
|
if (cachep) {
|
|
cachep->refcount++;
|
|
|
|
/*
|
|
* Adjust the object sizes so that we clear
|
|
* the complete object on kzalloc.
|
|
*/
|
|
cachep->object_size = max_t(int, cachep->object_size, size);
|
|
}
|
|
return cachep;
|
|
}
|
|
|
|
static bool set_objfreelist_slab_cache(struct kmem_cache *cachep,
|
|
size_t size, unsigned long flags)
|
|
{
|
|
size_t left;
|
|
|
|
cachep->num = 0;
|
|
|
|
if (cachep->ctor || flags & SLAB_DESTROY_BY_RCU)
|
|
return false;
|
|
|
|
left = calculate_slab_order(cachep, size,
|
|
flags | CFLGS_OBJFREELIST_SLAB);
|
|
if (!cachep->num)
|
|
return false;
|
|
|
|
if (cachep->num * sizeof(freelist_idx_t) > cachep->object_size)
|
|
return false;
|
|
|
|
cachep->colour = left / cachep->colour_off;
|
|
|
|
return true;
|
|
}
|
|
|
|
static bool set_off_slab_cache(struct kmem_cache *cachep,
|
|
size_t size, unsigned long flags)
|
|
{
|
|
size_t left;
|
|
|
|
cachep->num = 0;
|
|
|
|
/*
|
|
* Always use on-slab management when SLAB_NOLEAKTRACE
|
|
* to avoid recursive calls into kmemleak.
|
|
*/
|
|
if (flags & SLAB_NOLEAKTRACE)
|
|
return false;
|
|
|
|
/*
|
|
* Size is large, assume best to place the slab management obj
|
|
* off-slab (should allow better packing of objs).
|
|
*/
|
|
left = calculate_slab_order(cachep, size, flags | CFLGS_OFF_SLAB);
|
|
if (!cachep->num)
|
|
return false;
|
|
|
|
/*
|
|
* 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 (left >= cachep->num * sizeof(freelist_idx_t))
|
|
return false;
|
|
|
|
cachep->colour = left / cachep->colour_off;
|
|
|
|
return true;
|
|
}
|
|
|
|
static bool set_on_slab_cache(struct kmem_cache *cachep,
|
|
size_t size, unsigned long flags)
|
|
{
|
|
size_t left;
|
|
|
|
cachep->num = 0;
|
|
|
|
left = calculate_slab_order(cachep, size, flags);
|
|
if (!cachep->num)
|
|
return false;
|
|
|
|
cachep->colour = left / cachep->colour_off;
|
|
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* __kmem_cache_create - Create a cache.
|
|
* @cachep: cache management descriptor
|
|
* @flags: SLAB flags
|
|
*
|
|
* 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.
|
|
*
|
|
* 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.
|
|
*/
|
|
int
|
|
__kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
|
|
{
|
|
size_t ralign = BYTES_PER_WORD;
|
|
gfp_t gfp;
|
|
int err;
|
|
size_t size = cachep->size;
|
|
|
|
#if DEBUG
|
|
#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
|
|
#endif
|
|
|
|
/*
|
|
* 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);
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
/* 3) caller mandated alignment */
|
|
if (ralign < cachep->align) {
|
|
ralign = cachep->align;
|
|
}
|
|
/* disable debug if necessary */
|
|
if (ralign > __alignof__(unsigned long long))
|
|
flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
|
|
/*
|
|
* 4) Store it.
|
|
*/
|
|
cachep->align = ralign;
|
|
cachep->colour_off = cache_line_size();
|
|
/* Offset must be a multiple of the alignment. */
|
|
if (cachep->colour_off < cachep->align)
|
|
cachep->colour_off = cachep->align;
|
|
|
|
if (slab_is_available())
|
|
gfp = GFP_KERNEL;
|
|
else
|
|
gfp = GFP_NOWAIT;
|
|
|
|
#if DEBUG
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
#endif
|
|
|
|
kasan_cache_create(cachep, &size, &flags);
|
|
|
|
size = ALIGN(size, cachep->align);
|
|
/*
|
|
* We should restrict the number of objects in a slab to implement
|
|
* byte sized index. Refer comment on SLAB_OBJ_MIN_SIZE definition.
|
|
*/
|
|
if (FREELIST_BYTE_INDEX && size < SLAB_OBJ_MIN_SIZE)
|
|
size = ALIGN(SLAB_OBJ_MIN_SIZE, cachep->align);
|
|
|
|
#if DEBUG
|
|
/*
|
|
* To activate debug pagealloc, off-slab management is necessary
|
|
* requirement. In early phase of initialization, small sized slab
|
|
* doesn't get initialized so it would not be possible. So, we need
|
|
* to check size >= 256. It guarantees that all necessary small
|
|
* sized slab is initialized in current slab initialization sequence.
|
|
*/
|
|
if (debug_pagealloc_enabled() && (flags & SLAB_POISON) &&
|
|
size >= 256 && cachep->object_size > cache_line_size()) {
|
|
if (size < PAGE_SIZE || size % PAGE_SIZE == 0) {
|
|
size_t tmp_size = ALIGN(size, PAGE_SIZE);
|
|
|
|
if (set_off_slab_cache(cachep, tmp_size, flags)) {
|
|
flags |= CFLGS_OFF_SLAB;
|
|
cachep->obj_offset += tmp_size - size;
|
|
size = tmp_size;
|
|
goto done;
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
if (set_objfreelist_slab_cache(cachep, size, flags)) {
|
|
flags |= CFLGS_OBJFREELIST_SLAB;
|
|
goto done;
|
|
}
|
|
|
|
if (set_off_slab_cache(cachep, size, flags)) {
|
|
flags |= CFLGS_OFF_SLAB;
|
|
goto done;
|
|
}
|
|
|
|
if (set_on_slab_cache(cachep, size, flags))
|
|
goto done;
|
|
|
|
return -E2BIG;
|
|
|
|
done:
|
|
cachep->freelist_size = cachep->num * sizeof(freelist_idx_t);
|
|
cachep->flags = flags;
|
|
cachep->allocflags = __GFP_COMP;
|
|
if (flags & SLAB_CACHE_DMA)
|
|
cachep->allocflags |= GFP_DMA;
|
|
cachep->size = size;
|
|
cachep->reciprocal_buffer_size = reciprocal_value(size);
|
|
|
|
#if DEBUG
|
|
/*
|
|
* If we're going to use the generic kernel_map_pages()
|
|
* poisoning, then it's going to smash the contents of
|
|
* the redzone and userword anyhow, so switch them off.
|
|
*/
|
|
if (IS_ENABLED(CONFIG_PAGE_POISONING) &&
|
|
(cachep->flags & SLAB_POISON) &&
|
|
is_debug_pagealloc_cache(cachep))
|
|
cachep->flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
|
|
#endif
|
|
|
|
if (OFF_SLAB(cachep)) {
|
|
cachep->freelist_cache =
|
|
kmalloc_slab(cachep->freelist_size, 0u);
|
|
}
|
|
|
|
err = setup_cpu_cache(cachep, gfp);
|
|
if (err) {
|
|
__kmem_cache_release(cachep);
|
|
return err;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
#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_mutex_acquired(void)
|
|
{
|
|
BUG_ON(!mutex_is_locked(&slab_mutex));
|
|
}
|
|
|
|
static void check_spinlock_acquired(struct kmem_cache *cachep)
|
|
{
|
|
#ifdef CONFIG_SMP
|
|
check_irq_off();
|
|
assert_spin_locked(&get_node(cachep, numa_mem_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(&get_node(cachep, node)->list_lock);
|
|
#endif
|
|
}
|
|
|
|
#else
|
|
#define check_irq_off() do { } while(0)
|
|
#define check_irq_on() do { } while(0)
|
|
#define check_mutex_acquired() 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_locked(struct kmem_cache *cachep, struct array_cache *ac,
|
|
int node, bool free_all, struct list_head *list)
|
|
{
|
|
int tofree;
|
|
|
|
if (!ac || !ac->avail)
|
|
return;
|
|
|
|
tofree = free_all ? ac->avail : (ac->limit + 4) / 5;
|
|
if (tofree > ac->avail)
|
|
tofree = (ac->avail + 1) / 2;
|
|
|
|
free_block(cachep, ac->entry, tofree, node, list);
|
|
ac->avail -= tofree;
|
|
memmove(ac->entry, &(ac->entry[tofree]), sizeof(void *) * ac->avail);
|
|
}
|
|
|
|
static void do_drain(void *arg)
|
|
{
|
|
struct kmem_cache *cachep = arg;
|
|
struct array_cache *ac;
|
|
int node = numa_mem_id();
|
|
struct kmem_cache_node *n;
|
|
LIST_HEAD(list);
|
|
|
|
check_irq_off();
|
|
ac = cpu_cache_get(cachep);
|
|
n = get_node(cachep, node);
|
|
spin_lock(&n->list_lock);
|
|
free_block(cachep, ac->entry, ac->avail, node, &list);
|
|
spin_unlock(&n->list_lock);
|
|
slabs_destroy(cachep, &list);
|
|
ac->avail = 0;
|
|
}
|
|
|
|
static void drain_cpu_caches(struct kmem_cache *cachep)
|
|
{
|
|
struct kmem_cache_node *n;
|
|
int node;
|
|
LIST_HEAD(list);
|
|
|
|
on_each_cpu(do_drain, cachep, 1);
|
|
check_irq_on();
|
|
for_each_kmem_cache_node(cachep, node, n)
|
|
if (n->alien)
|
|
drain_alien_cache(cachep, n->alien);
|
|
|
|
for_each_kmem_cache_node(cachep, node, n) {
|
|
spin_lock_irq(&n->list_lock);
|
|
drain_array_locked(cachep, n->shared, node, true, &list);
|
|
spin_unlock_irq(&n->list_lock);
|
|
|
|
slabs_destroy(cachep, &list);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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_cache_node *n, int tofree)
|
|
{
|
|
struct list_head *p;
|
|
int nr_freed;
|
|
struct page *page;
|
|
|
|
nr_freed = 0;
|
|
while (nr_freed < tofree && !list_empty(&n->slabs_free)) {
|
|
|
|
spin_lock_irq(&n->list_lock);
|
|
p = n->slabs_free.prev;
|
|
if (p == &n->slabs_free) {
|
|
spin_unlock_irq(&n->list_lock);
|
|
goto out;
|
|
}
|
|
|
|
page = list_entry(p, struct page, lru);
|
|
list_del(&page->lru);
|
|
/*
|
|
* Safe to drop the lock. The slab is no longer linked
|
|
* to the cache.
|
|
*/
|
|
n->free_objects -= cache->num;
|
|
spin_unlock_irq(&n->list_lock);
|
|
slab_destroy(cache, page);
|
|
nr_freed++;
|
|
}
|
|
out:
|
|
return nr_freed;
|
|
}
|
|
|
|
int __kmem_cache_shrink(struct kmem_cache *cachep, bool deactivate)
|
|
{
|
|
int ret = 0;
|
|
int node;
|
|
struct kmem_cache_node *n;
|
|
|
|
drain_cpu_caches(cachep);
|
|
|
|
check_irq_on();
|
|
for_each_kmem_cache_node(cachep, node, n) {
|
|
drain_freelist(cachep, n, INT_MAX);
|
|
|
|
ret += !list_empty(&n->slabs_full) ||
|
|
!list_empty(&n->slabs_partial);
|
|
}
|
|
return (ret ? 1 : 0);
|
|
}
|
|
|
|
int __kmem_cache_shutdown(struct kmem_cache *cachep)
|
|
{
|
|
return __kmem_cache_shrink(cachep, false);
|
|
}
|
|
|
|
void __kmem_cache_release(struct kmem_cache *cachep)
|
|
{
|
|
int i;
|
|
struct kmem_cache_node *n;
|
|
|
|
cache_random_seq_destroy(cachep);
|
|
|
|
free_percpu(cachep->cpu_cache);
|
|
|
|
/* NUMA: free the node structures */
|
|
for_each_kmem_cache_node(cachep, i, n) {
|
|
kfree(n->shared);
|
|
free_alien_cache(n->alien);
|
|
kfree(n);
|
|
cachep->node[i] = NULL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Get the memory for a slab management obj.
|
|
*
|
|
* For a slab cache when the slab descriptor is off-slab, the
|
|
* slab descriptor can't come from the same cache which is being created,
|
|
* Because if it is the case, that means we defer the creation of
|
|
* the kmalloc_{dma,}_cache of size sizeof(slab descriptor) to this point.
|
|
* And we eventually call down to __kmem_cache_create(), which
|
|
* in turn looks up in the kmalloc_{dma,}_caches for the disired-size one.
|
|
* This is a "chicken-and-egg" problem.
|
|
*
|
|
* So the off-slab slab descriptor shall come from the kmalloc_{dma,}_caches,
|
|
* which are all initialized during kmem_cache_init().
|
|
*/
|
|
static void *alloc_slabmgmt(struct kmem_cache *cachep,
|
|
struct page *page, int colour_off,
|
|
gfp_t local_flags, int nodeid)
|
|
{
|
|
void *freelist;
|
|
void *addr = page_address(page);
|
|
|
|
page->s_mem = addr + colour_off;
|
|
page->active = 0;
|
|
|
|
if (OBJFREELIST_SLAB(cachep))
|
|
freelist = NULL;
|
|
else if (OFF_SLAB(cachep)) {
|
|
/* Slab management obj is off-slab. */
|
|
freelist = kmem_cache_alloc_node(cachep->freelist_cache,
|
|
local_flags, nodeid);
|
|
if (!freelist)
|
|
return NULL;
|
|
} else {
|
|
/* We will use last bytes at the slab for freelist */
|
|
freelist = addr + (PAGE_SIZE << cachep->gfporder) -
|
|
cachep->freelist_size;
|
|
}
|
|
|
|
return freelist;
|
|
}
|
|
|
|
static inline freelist_idx_t get_free_obj(struct page *page, unsigned int idx)
|
|
{
|
|
return ((freelist_idx_t *)page->freelist)[idx];
|
|
}
|
|
|
|
static inline void set_free_obj(struct page *page,
|
|
unsigned int idx, freelist_idx_t val)
|
|
{
|
|
((freelist_idx_t *)(page->freelist))[idx] = val;
|
|
}
|
|
|
|
static void cache_init_objs_debug(struct kmem_cache *cachep, struct page *page)
|
|
{
|
|
#if DEBUG
|
|
int i;
|
|
|
|
for (i = 0; i < cachep->num; i++) {
|
|
void *objp = index_to_obj(cachep, page, i);
|
|
|
|
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)) {
|
|
kasan_unpoison_object_data(cachep,
|
|
objp + obj_offset(cachep));
|
|
cachep->ctor(objp + obj_offset(cachep));
|
|
kasan_poison_object_data(
|
|
cachep, 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");
|
|
}
|
|
/* need to poison the objs? */
|
|
if (cachep->flags & SLAB_POISON) {
|
|
poison_obj(cachep, objp, POISON_FREE);
|
|
slab_kernel_map(cachep, objp, 0, 0);
|
|
}
|
|
}
|
|
#endif
|
|
}
|
|
|
|
#ifdef CONFIG_SLAB_FREELIST_RANDOM
|
|
/* Hold information during a freelist initialization */
|
|
union freelist_init_state {
|
|
struct {
|
|
unsigned int pos;
|
|
freelist_idx_t *list;
|
|
unsigned int count;
|
|
unsigned int rand;
|
|
};
|
|
struct rnd_state rnd_state;
|
|
};
|
|
|
|
/*
|
|
* Initialize the state based on the randomization methode available.
|
|
* return true if the pre-computed list is available, false otherwize.
|
|
*/
|
|
static bool freelist_state_initialize(union freelist_init_state *state,
|
|
struct kmem_cache *cachep,
|
|
unsigned int count)
|
|
{
|
|
bool ret;
|
|
unsigned int rand;
|
|
|
|
/* Use best entropy available to define a random shift */
|
|
get_random_bytes_arch(&rand, sizeof(rand));
|
|
|
|
/* Use a random state if the pre-computed list is not available */
|
|
if (!cachep->random_seq) {
|
|
prandom_seed_state(&state->rnd_state, rand);
|
|
ret = false;
|
|
} else {
|
|
state->list = cachep->random_seq;
|
|
state->count = count;
|
|
state->pos = 0;
|
|
state->rand = rand;
|
|
ret = true;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/* Get the next entry on the list and randomize it using a random shift */
|
|
static freelist_idx_t next_random_slot(union freelist_init_state *state)
|
|
{
|
|
return (state->list[state->pos++] + state->rand) % state->count;
|
|
}
|
|
|
|
/*
|
|
* Shuffle the freelist initialization state based on pre-computed lists.
|
|
* return true if the list was successfully shuffled, false otherwise.
|
|
*/
|
|
static bool shuffle_freelist(struct kmem_cache *cachep, struct page *page)
|
|
{
|
|
unsigned int objfreelist = 0, i, count = cachep->num;
|
|
union freelist_init_state state;
|
|
bool precomputed;
|
|
|
|
if (count < 2)
|
|
return false;
|
|
|
|
precomputed = freelist_state_initialize(&state, cachep, count);
|
|
|
|
/* Take a random entry as the objfreelist */
|
|
if (OBJFREELIST_SLAB(cachep)) {
|
|
if (!precomputed)
|
|
objfreelist = count - 1;
|
|
else
|
|
objfreelist = next_random_slot(&state);
|
|
page->freelist = index_to_obj(cachep, page, objfreelist) +
|
|
obj_offset(cachep);
|
|
count--;
|
|
}
|
|
|
|
/*
|
|
* On early boot, generate the list dynamically.
|
|
* Later use a pre-computed list for speed.
|
|
*/
|
|
if (!precomputed) {
|
|
freelist_randomize(&state.rnd_state, page->freelist, count);
|
|
} else {
|
|
for (i = 0; i < count; i++)
|
|
set_free_obj(page, i, next_random_slot(&state));
|
|
}
|
|
|
|
if (OBJFREELIST_SLAB(cachep))
|
|
set_free_obj(page, cachep->num - 1, objfreelist);
|
|
|
|
return true;
|
|
}
|
|
#else
|
|
static inline bool shuffle_freelist(struct kmem_cache *cachep,
|
|
struct page *page)
|
|
{
|
|
return false;
|
|
}
|
|
#endif /* CONFIG_SLAB_FREELIST_RANDOM */
|
|
|
|
static void cache_init_objs(struct kmem_cache *cachep,
|
|
struct page *page)
|
|
{
|
|
int i;
|
|
void *objp;
|
|
bool shuffled;
|
|
|
|
cache_init_objs_debug(cachep, page);
|
|
|
|
/* Try to randomize the freelist if enabled */
|
|
shuffled = shuffle_freelist(cachep, page);
|
|
|
|
if (!shuffled && OBJFREELIST_SLAB(cachep)) {
|
|
page->freelist = index_to_obj(cachep, page, cachep->num - 1) +
|
|
obj_offset(cachep);
|
|
}
|
|
|
|
for (i = 0; i < cachep->num; i++) {
|
|
/* constructor could break poison info */
|
|
if (DEBUG == 0 && cachep->ctor) {
|
|
objp = index_to_obj(cachep, page, i);
|
|
kasan_unpoison_object_data(cachep, objp);
|
|
cachep->ctor(objp);
|
|
kasan_poison_object_data(cachep, objp);
|
|
}
|
|
|
|
if (!shuffled)
|
|
set_free_obj(page, i, i);
|
|
}
|
|
}
|
|
|
|
static void *slab_get_obj(struct kmem_cache *cachep, struct page *page)
|
|
{
|
|
void *objp;
|
|
|
|
objp = index_to_obj(cachep, page, get_free_obj(page, page->active));
|
|
page->active++;
|
|
|
|
#if DEBUG
|
|
if (cachep->flags & SLAB_STORE_USER)
|
|
set_store_user_dirty(cachep);
|
|
#endif
|
|
|
|
return objp;
|
|
}
|
|
|
|
static void slab_put_obj(struct kmem_cache *cachep,
|
|
struct page *page, void *objp)
|
|
{
|
|
unsigned int objnr = obj_to_index(cachep, page, objp);
|
|
#if DEBUG
|
|
unsigned int i;
|
|
|
|
/* Verify double free bug */
|
|
for (i = page->active; i < cachep->num; i++) {
|
|
if (get_free_obj(page, i) == objnr) {
|
|
pr_err("slab: double free detected in cache '%s', objp %p\n",
|
|
cachep->name, objp);
|
|
BUG();
|
|
}
|
|
}
|
|
#endif
|
|
page->active--;
|
|
if (!page->freelist)
|
|
page->freelist = objp + obj_offset(cachep);
|
|
|
|
set_free_obj(page, page->active, objnr);
|
|
}
|
|
|
|
/*
|
|
* 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, and slab debugging.
|
|
*/
|
|
static void slab_map_pages(struct kmem_cache *cache, struct page *page,
|
|
void *freelist)
|
|
{
|
|
page->slab_cache = cache;
|
|
page->freelist = freelist;
|
|
}
|
|
|
|
/*
|
|
* 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 struct page *cache_grow_begin(struct kmem_cache *cachep,
|
|
gfp_t flags, int nodeid)
|
|
{
|
|
void *freelist;
|
|
size_t offset;
|
|
gfp_t local_flags;
|
|
int page_node;
|
|
struct kmem_cache_node *n;
|
|
struct page *page;
|
|
|
|
/*
|
|
* Be lazy and only check for valid flags here, keeping it out of the
|
|
* critical path in kmem_cache_alloc().
|
|
*/
|
|
if (unlikely(flags & GFP_SLAB_BUG_MASK)) {
|
|
pr_emerg("gfp: %u\n", flags & GFP_SLAB_BUG_MASK);
|
|
BUG();
|
|
}
|
|
local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK);
|
|
|
|
check_irq_off();
|
|
if (gfpflags_allow_blocking(local_flags))
|
|
local_irq_enable();
|
|
|
|
/*
|
|
* Get mem for the objs. Attempt to allocate a physical page from
|
|
* 'nodeid'.
|
|
*/
|
|
page = kmem_getpages(cachep, local_flags, nodeid);
|
|
if (!page)
|
|
goto failed;
|
|
|
|
page_node = page_to_nid(page);
|
|
n = get_node(cachep, page_node);
|
|
|
|
/* Get colour for the slab, and cal the next value. */
|
|
n->colour_next++;
|
|
if (n->colour_next >= cachep->colour)
|
|
n->colour_next = 0;
|
|
|
|
offset = n->colour_next;
|
|
if (offset >= cachep->colour)
|
|
offset = 0;
|
|
|
|
offset *= cachep->colour_off;
|
|
|
|
/* Get slab management. */
|
|
freelist = alloc_slabmgmt(cachep, page, offset,
|
|
local_flags & ~GFP_CONSTRAINT_MASK, page_node);
|
|
if (OFF_SLAB(cachep) && !freelist)
|
|
goto opps1;
|
|
|
|
slab_map_pages(cachep, page, freelist);
|
|
|
|
kasan_poison_slab(page);
|
|
cache_init_objs(cachep, page);
|
|
|
|
if (gfpflags_allow_blocking(local_flags))
|
|
local_irq_disable();
|
|
|
|
return page;
|
|
|
|
opps1:
|
|
kmem_freepages(cachep, page);
|
|
failed:
|
|
if (gfpflags_allow_blocking(local_flags))
|
|
local_irq_disable();
|
|
return NULL;
|
|
}
|
|
|
|
static void cache_grow_end(struct kmem_cache *cachep, struct page *page)
|
|
{
|
|
struct kmem_cache_node *n;
|
|
void *list = NULL;
|
|
|
|
check_irq_off();
|
|
|
|
if (!page)
|
|
return;
|
|
|
|
INIT_LIST_HEAD(&page->lru);
|
|
n = get_node(cachep, page_to_nid(page));
|
|
|
|
spin_lock(&n->list_lock);
|
|
if (!page->active)
|
|
list_add_tail(&page->lru, &(n->slabs_free));
|
|
else
|
|
fixup_slab_list(cachep, n, page, &list);
|
|
STATS_INC_GROWN(cachep);
|
|
n->free_objects += cachep->num - page->active;
|
|
spin_unlock(&n->list_lock);
|
|
|
|
fixup_objfreelist_debug(cachep, &list);
|
|
}
|
|
|
|
#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)) {
|
|
pr_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");
|
|
|
|
pr_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,
|
|
unsigned long caller)
|
|
{
|
|
unsigned int objnr;
|
|
struct page *page;
|
|
|
|
BUG_ON(virt_to_cache(objp) != cachep);
|
|
|
|
objp -= obj_offset(cachep);
|
|
kfree_debugcheck(objp);
|
|
page = virt_to_head_page(objp);
|
|
|
|
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) {
|
|
set_store_user_dirty(cachep);
|
|
*dbg_userword(cachep, objp) = (void *)caller;
|
|
}
|
|
|
|
objnr = obj_to_index(cachep, page, objp);
|
|
|
|
BUG_ON(objnr >= cachep->num);
|
|
BUG_ON(objp != index_to_obj(cachep, page, objnr));
|
|
|
|
if (cachep->flags & SLAB_POISON) {
|
|
poison_obj(cachep, objp, POISON_FREE);
|
|
slab_kernel_map(cachep, objp, 0, caller);
|
|
}
|
|
return objp;
|
|
}
|
|
|
|
#else
|
|
#define kfree_debugcheck(x) do { } while(0)
|
|
#define cache_free_debugcheck(x,objp,z) (objp)
|
|
#endif
|
|
|
|
static inline void fixup_objfreelist_debug(struct kmem_cache *cachep,
|
|
void **list)
|
|
{
|
|
#if DEBUG
|
|
void *next = *list;
|
|
void *objp;
|
|
|
|
while (next) {
|
|
objp = next - obj_offset(cachep);
|
|
next = *(void **)next;
|
|
poison_obj(cachep, objp, POISON_FREE);
|
|
}
|
|
#endif
|
|
}
|
|
|
|
static inline void fixup_slab_list(struct kmem_cache *cachep,
|
|
struct kmem_cache_node *n, struct page *page,
|
|
void **list)
|
|
{
|
|
/* move slabp to correct slabp list: */
|
|
list_del(&page->lru);
|
|
if (page->active == cachep->num) {
|
|
list_add(&page->lru, &n->slabs_full);
|
|
if (OBJFREELIST_SLAB(cachep)) {
|
|
#if DEBUG
|
|
/* Poisoning will be done without holding the lock */
|
|
if (cachep->flags & SLAB_POISON) {
|
|
void **objp = page->freelist;
|
|
|
|
*objp = *list;
|
|
*list = objp;
|
|
}
|
|
#endif
|
|
page->freelist = NULL;
|
|
}
|
|
} else
|
|
list_add(&page->lru, &n->slabs_partial);
|
|
}
|
|
|
|
/* Try to find non-pfmemalloc slab if needed */
|
|
static noinline struct page *get_valid_first_slab(struct kmem_cache_node *n,
|
|
struct page *page, bool pfmemalloc)
|
|
{
|
|
if (!page)
|
|
return NULL;
|
|
|
|
if (pfmemalloc)
|
|
return page;
|
|
|
|
if (!PageSlabPfmemalloc(page))
|
|
return page;
|
|
|
|
/* No need to keep pfmemalloc slab if we have enough free objects */
|
|
if (n->free_objects > n->free_limit) {
|
|
ClearPageSlabPfmemalloc(page);
|
|
return page;
|
|
}
|
|
|
|
/* Move pfmemalloc slab to the end of list to speed up next search */
|
|
list_del(&page->lru);
|
|
if (!page->active)
|
|
list_add_tail(&page->lru, &n->slabs_free);
|
|
else
|
|
list_add_tail(&page->lru, &n->slabs_partial);
|
|
|
|
list_for_each_entry(page, &n->slabs_partial, lru) {
|
|
if (!PageSlabPfmemalloc(page))
|
|
return page;
|
|
}
|
|
|
|
list_for_each_entry(page, &n->slabs_free, lru) {
|
|
if (!PageSlabPfmemalloc(page))
|
|
return page;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static struct page *get_first_slab(struct kmem_cache_node *n, bool pfmemalloc)
|
|
{
|
|
struct page *page;
|
|
|
|
page = list_first_entry_or_null(&n->slabs_partial,
|
|
struct page, lru);
|
|
if (!page) {
|
|
n->free_touched = 1;
|
|
page = list_first_entry_or_null(&n->slabs_free,
|
|
struct page, lru);
|
|
}
|
|
|
|
if (sk_memalloc_socks())
|
|
return get_valid_first_slab(n, page, pfmemalloc);
|
|
|
|
return page;
|
|
}
|
|
|
|
static noinline void *cache_alloc_pfmemalloc(struct kmem_cache *cachep,
|
|
struct kmem_cache_node *n, gfp_t flags)
|
|
{
|
|
struct page *page;
|
|
void *obj;
|
|
void *list = NULL;
|
|
|
|
if (!gfp_pfmemalloc_allowed(flags))
|
|
return NULL;
|
|
|
|
spin_lock(&n->list_lock);
|
|
page = get_first_slab(n, true);
|
|
if (!page) {
|
|
spin_unlock(&n->list_lock);
|
|
return NULL;
|
|
}
|
|
|
|
obj = slab_get_obj(cachep, page);
|
|
n->free_objects--;
|
|
|
|
fixup_slab_list(cachep, n, page, &list);
|
|
|
|
spin_unlock(&n->list_lock);
|
|
fixup_objfreelist_debug(cachep, &list);
|
|
|
|
return obj;
|
|
}
|
|
|
|
/*
|
|
* Slab list should be fixed up by fixup_slab_list() for existing slab
|
|
* or cache_grow_end() for new slab
|
|
*/
|
|
static __always_inline int alloc_block(struct kmem_cache *cachep,
|
|
struct array_cache *ac, struct page *page, int batchcount)
|
|
{
|
|
/*
|
|
* There must be at least one object available for
|
|
* allocation.
|
|
*/
|
|
BUG_ON(page->active >= cachep->num);
|
|
|
|
while (page->active < cachep->num && batchcount--) {
|
|
STATS_INC_ALLOCED(cachep);
|
|
STATS_INC_ACTIVE(cachep);
|
|
STATS_SET_HIGH(cachep);
|
|
|
|
ac->entry[ac->avail++] = slab_get_obj(cachep, page);
|
|
}
|
|
|
|
return batchcount;
|
|
}
|
|
|
|
static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags)
|
|
{
|
|
int batchcount;
|
|
struct kmem_cache_node *n;
|
|
struct array_cache *ac, *shared;
|
|
int node;
|
|
void *list = NULL;
|
|
struct page *page;
|
|
|
|
check_irq_off();
|
|
node = numa_mem_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;
|
|
}
|
|
n = get_node(cachep, node);
|
|
|
|
BUG_ON(ac->avail > 0 || !n);
|
|
shared = READ_ONCE(n->shared);
|
|
if (!n->free_objects && (!shared || !shared->avail))
|
|
goto direct_grow;
|
|
|
|
spin_lock(&n->list_lock);
|
|
shared = READ_ONCE(n->shared);
|
|
|
|
/* See if we can refill from the shared array */
|
|
if (shared && transfer_objects(ac, shared, batchcount)) {
|
|
shared->touched = 1;
|
|
goto alloc_done;
|
|
}
|
|
|
|
while (batchcount > 0) {
|
|
/* Get slab alloc is to come from. */
|
|
page = get_first_slab(n, false);
|
|
if (!page)
|
|
goto must_grow;
|
|
|
|
check_spinlock_acquired(cachep);
|
|
|
|
batchcount = alloc_block(cachep, ac, page, batchcount);
|
|
fixup_slab_list(cachep, n, page, &list);
|
|
}
|
|
|
|
must_grow:
|
|
n->free_objects -= ac->avail;
|
|
alloc_done:
|
|
spin_unlock(&n->list_lock);
|
|
fixup_objfreelist_debug(cachep, &list);
|
|
|
|
direct_grow:
|
|
if (unlikely(!ac->avail)) {
|
|
/* Check if we can use obj in pfmemalloc slab */
|
|
if (sk_memalloc_socks()) {
|
|
void *obj = cache_alloc_pfmemalloc(cachep, n, flags);
|
|
|
|
if (obj)
|
|
return obj;
|
|
}
|
|
|
|
page = cache_grow_begin(cachep, gfp_exact_node(flags), node);
|
|
|
|
/*
|
|
* cache_grow_begin() can reenable interrupts,
|
|
* then ac could change.
|
|
*/
|
|
ac = cpu_cache_get(cachep);
|
|
if (!ac->avail && page)
|
|
alloc_block(cachep, ac, page, batchcount);
|
|
cache_grow_end(cachep, page);
|
|
|
|
if (!ac->avail)
|
|
return NULL;
|
|
}
|
|
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(gfpflags_allow_blocking(flags));
|
|
}
|
|
|
|
#if DEBUG
|
|
static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
|
|
gfp_t flags, void *objp, unsigned long caller)
|
|
{
|
|
if (!objp)
|
|
return objp;
|
|
if (cachep->flags & SLAB_POISON) {
|
|
check_poison_obj(cachep, objp);
|
|
slab_kernel_map(cachep, objp, 1, 0);
|
|
poison_obj(cachep, objp, POISON_INUSE);
|
|
}
|
|
if (cachep->flags & SLAB_STORE_USER)
|
|
*dbg_userword(cachep, objp) = (void *)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");
|
|
pr_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;
|
|
}
|
|
|
|
objp += obj_offset(cachep);
|
|
if (cachep->ctor && cachep->flags & SLAB_POISON)
|
|
cachep->ctor(objp);
|
|
if (ARCH_SLAB_MINALIGN &&
|
|
((unsigned long)objp & (ARCH_SLAB_MINALIGN-1))) {
|
|
pr_err("0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n",
|
|
objp, (int)ARCH_SLAB_MINALIGN);
|
|
}
|
|
return objp;
|
|
}
|
|
#else
|
|
#define cache_alloc_debugcheck_after(a,b,objp,d) (objp)
|
|
#endif
|
|
|
|
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)) {
|
|
ac->touched = 1;
|
|
objp = ac->entry[--ac->avail];
|
|
|
|
STATS_INC_ALLOCHIT(cachep);
|
|
goto out;
|
|
}
|
|
|
|
STATS_INC_ALLOCMISS(cachep);
|
|
objp = cache_alloc_refill(cachep, flags);
|
|
/*
|
|
* the 'ac' may be updated by cache_alloc_refill(),
|
|
* and kmemleak_erase() requires its correct value.
|
|
*/
|
|
ac = cpu_cache_get(cachep);
|
|
|
|
out:
|
|
/*
|
|
* To avoid a false negative, if an object that is in one of the
|
|
* per-CPU caches is leaked, we need to make sure kmemleak doesn't
|
|
* treat the array pointers as a reference to the object.
|
|
*/
|
|
if (objp)
|
|
kmemleak_erase(&ac->entry[ac->avail]);
|
|
return objp;
|
|
}
|
|
|
|
#ifdef CONFIG_NUMA
|
|
/*
|
|
* Try allocating on another node if PFA_SPREAD_SLAB is a mempolicy is set.
|
|
*
|
|
* 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_mem_id();
|
|
if (cpuset_do_slab_mem_spread() && (cachep->flags & SLAB_MEM_SPREAD))
|
|
nid_alloc = cpuset_slab_spread_node();
|
|
else if (current->mempolicy)
|
|
nid_alloc = mempolicy_slab_node();
|
|
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 node 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;
|
|
struct zoneref *z;
|
|
struct zone *zone;
|
|
enum zone_type high_zoneidx = gfp_zone(flags);
|
|
void *obj = NULL;
|
|
struct page *page;
|
|
int nid;
|
|
unsigned int cpuset_mems_cookie;
|
|
|
|
if (flags & __GFP_THISNODE)
|
|
return NULL;
|
|
|
|
retry_cpuset:
|
|
cpuset_mems_cookie = read_mems_allowed_begin();
|
|
zonelist = node_zonelist(mempolicy_slab_node(), flags);
|
|
|
|
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(zone, flags) &&
|
|
get_node(cache, nid) &&
|
|
get_node(cache, nid)->free_objects) {
|
|
obj = ____cache_alloc_node(cache,
|
|
gfp_exact_node(flags), 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.
|
|
*/
|
|
page = cache_grow_begin(cache, flags, numa_mem_id());
|
|
cache_grow_end(cache, page);
|
|
if (page) {
|
|
nid = page_to_nid(page);
|
|
obj = ____cache_alloc_node(cache,
|
|
gfp_exact_node(flags), nid);
|
|
|
|
/*
|
|
* Another processor may allocate the objects in
|
|
* the slab since we are not holding any locks.
|
|
*/
|
|
if (!obj)
|
|
goto retry;
|
|
}
|
|
}
|
|
|
|
if (unlikely(!obj && read_mems_allowed_retry(cpuset_mems_cookie)))
|
|
goto retry_cpuset;
|
|
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 page *page;
|
|
struct kmem_cache_node *n;
|
|
void *obj = NULL;
|
|
void *list = NULL;
|
|
|
|
VM_BUG_ON(nodeid < 0 || nodeid >= MAX_NUMNODES);
|
|
n = get_node(cachep, nodeid);
|
|
BUG_ON(!n);
|
|
|
|
check_irq_off();
|
|
spin_lock(&n->list_lock);
|
|
page = get_first_slab(n, false);
|
|
if (!page)
|
|
goto must_grow;
|
|
|
|
check_spinlock_acquired_node(cachep, nodeid);
|
|
|
|
STATS_INC_NODEALLOCS(cachep);
|
|
STATS_INC_ACTIVE(cachep);
|
|
STATS_SET_HIGH(cachep);
|
|
|
|
BUG_ON(page->active == cachep->num);
|
|
|
|
obj = slab_get_obj(cachep, page);
|
|
n->free_objects--;
|
|
|
|
fixup_slab_list(cachep, n, page, &list);
|
|
|
|
spin_unlock(&n->list_lock);
|
|
fixup_objfreelist_debug(cachep, &list);
|
|
return obj;
|
|
|
|
must_grow:
|
|
spin_unlock(&n->list_lock);
|
|
page = cache_grow_begin(cachep, gfp_exact_node(flags), nodeid);
|
|
if (page) {
|
|
/* This slab isn't counted yet so don't update free_objects */
|
|
obj = slab_get_obj(cachep, page);
|
|
}
|
|
cache_grow_end(cachep, page);
|
|
|
|
return obj ? obj : fallback_alloc(cachep, flags);
|
|
}
|
|
|
|
static __always_inline void *
|
|
slab_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid,
|
|
unsigned long caller)
|
|
{
|
|
unsigned long save_flags;
|
|
void *ptr;
|
|
int slab_node = numa_mem_id();
|
|
|
|
flags &= gfp_allowed_mask;
|
|
cachep = slab_pre_alloc_hook(cachep, flags);
|
|
if (unlikely(!cachep))
|
|
return NULL;
|
|
|
|
cache_alloc_debugcheck_before(cachep, flags);
|
|
local_irq_save(save_flags);
|
|
|
|
if (nodeid == NUMA_NO_NODE)
|
|
nodeid = slab_node;
|
|
|
|
if (unlikely(!get_node(cachep, nodeid))) {
|
|
/* Node not bootstrapped yet */
|
|
ptr = fallback_alloc(cachep, flags);
|
|
goto out;
|
|
}
|
|
|
|
if (nodeid == slab_node) {
|
|
/*
|
|
* 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, cachep->object_size);
|
|
|
|
slab_post_alloc_hook(cachep, flags, 1, &ptr);
|
|
return ptr;
|
|
}
|
|
|
|
static __always_inline void *
|
|
__do_cache_alloc(struct kmem_cache *cache, gfp_t flags)
|
|
{
|
|
void *objp;
|
|
|
|
if (current->mempolicy || cpuset_do_slab_mem_spread()) {
|
|
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_mem_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 *
|
|
slab_alloc(struct kmem_cache *cachep, gfp_t flags, unsigned long caller)
|
|
{
|
|
unsigned long save_flags;
|
|
void *objp;
|
|
|
|
flags &= gfp_allowed_mask;
|
|
cachep = slab_pre_alloc_hook(cachep, flags);
|
|
if (unlikely(!cachep))
|
|
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, cachep->object_size);
|
|
|
|
slab_post_alloc_hook(cachep, flags, 1, &objp);
|
|
return objp;
|
|
}
|
|
|
|
/*
|
|
* Caller needs to acquire correct kmem_cache_node's list_lock
|
|
* @list: List of detached free slabs should be freed by caller
|
|
*/
|
|
static void free_block(struct kmem_cache *cachep, void **objpp,
|
|
int nr_objects, int node, struct list_head *list)
|
|
{
|
|
int i;
|
|
struct kmem_cache_node *n = get_node(cachep, node);
|
|
struct page *page;
|
|
|
|
n->free_objects += nr_objects;
|
|
|
|
for (i = 0; i < nr_objects; i++) {
|
|
void *objp;
|
|
struct page *page;
|
|
|
|
objp = objpp[i];
|
|
|
|
page = virt_to_head_page(objp);
|
|
list_del(&page->lru);
|
|
check_spinlock_acquired_node(cachep, node);
|
|
slab_put_obj(cachep, page, objp);
|
|
STATS_DEC_ACTIVE(cachep);
|
|
|
|
/* fixup slab chains */
|
|
if (page->active == 0)
|
|
list_add(&page->lru, &n->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(&page->lru, &n->slabs_partial);
|
|
}
|
|
}
|
|
|
|
while (n->free_objects > n->free_limit && !list_empty(&n->slabs_free)) {
|
|
n->free_objects -= cachep->num;
|
|
|
|
page = list_last_entry(&n->slabs_free, struct page, lru);
|
|
list_del(&page->lru);
|
|
list_add(&page->lru, list);
|
|
}
|
|
}
|
|
|
|
static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac)
|
|
{
|
|
int batchcount;
|
|
struct kmem_cache_node *n;
|
|
int node = numa_mem_id();
|
|
LIST_HEAD(list);
|
|
|
|
batchcount = ac->batchcount;
|
|
|
|
check_irq_off();
|
|
n = get_node(cachep, node);
|
|
spin_lock(&n->list_lock);
|
|
if (n->shared) {
|
|
struct array_cache *shared_array = n->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, &list);
|
|
free_done:
|
|
#if STATS
|
|
{
|
|
int i = 0;
|
|
struct page *page;
|
|
|
|
list_for_each_entry(page, &n->slabs_free, lru) {
|
|
BUG_ON(page->active);
|
|
|
|
i++;
|
|
}
|
|
STATS_SET_FREEABLE(cachep, i);
|
|
}
|
|
#endif
|
|
spin_unlock(&n->list_lock);
|
|
slabs_destroy(cachep, &list);
|
|
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,
|
|
unsigned long caller)
|
|
{
|
|
/* Put the object into the quarantine, don't touch it for now. */
|
|
if (kasan_slab_free(cachep, objp))
|
|
return;
|
|
|
|
___cache_free(cachep, objp, caller);
|
|
}
|
|
|
|
void ___cache_free(struct kmem_cache *cachep, void *objp,
|
|
unsigned long caller)
|
|
{
|
|
struct array_cache *ac = cpu_cache_get(cachep);
|
|
|
|
check_irq_off();
|
|
kmemleak_free_recursive(objp, cachep->flags);
|
|
objp = cache_free_debugcheck(cachep, objp, caller);
|
|
|
|
kmemcheck_slab_free(cachep, objp, cachep->object_size);
|
|
|
|
/*
|
|
* 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 (nr_online_nodes > 1 && cache_free_alien(cachep, objp))
|
|
return;
|
|
|
|
if (ac->avail < ac->limit) {
|
|
STATS_INC_FREEHIT(cachep);
|
|
} else {
|
|
STATS_INC_FREEMISS(cachep);
|
|
cache_flusharray(cachep, ac);
|
|
}
|
|
|
|
if (sk_memalloc_socks()) {
|
|
struct page *page = virt_to_head_page(objp);
|
|
|
|
if (unlikely(PageSlabPfmemalloc(page))) {
|
|
cache_free_pfmemalloc(cachep, page, objp);
|
|
return;
|
|
}
|
|
}
|
|
|
|
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)
|
|
{
|
|
void *ret = slab_alloc(cachep, flags, _RET_IP_);
|
|
|
|
kasan_slab_alloc(cachep, ret, flags);
|
|
trace_kmem_cache_alloc(_RET_IP_, ret,
|
|
cachep->object_size, cachep->size, flags);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_alloc);
|
|
|
|
static __always_inline void
|
|
cache_alloc_debugcheck_after_bulk(struct kmem_cache *s, gfp_t flags,
|
|
size_t size, void **p, unsigned long caller)
|
|
{
|
|
size_t i;
|
|
|
|
for (i = 0; i < size; i++)
|
|
p[i] = cache_alloc_debugcheck_after(s, flags, p[i], caller);
|
|
}
|
|
|
|
int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
|
|
void **p)
|
|
{
|
|
size_t i;
|
|
|
|
s = slab_pre_alloc_hook(s, flags);
|
|
if (!s)
|
|
return 0;
|
|
|
|
cache_alloc_debugcheck_before(s, flags);
|
|
|
|
local_irq_disable();
|
|
for (i = 0; i < size; i++) {
|
|
void *objp = __do_cache_alloc(s, flags);
|
|
|
|
if (unlikely(!objp))
|
|
goto error;
|
|
p[i] = objp;
|
|
}
|
|
local_irq_enable();
|
|
|
|
cache_alloc_debugcheck_after_bulk(s, flags, size, p, _RET_IP_);
|
|
|
|
/* Clear memory outside IRQ disabled section */
|
|
if (unlikely(flags & __GFP_ZERO))
|
|
for (i = 0; i < size; i++)
|
|
memset(p[i], 0, s->object_size);
|
|
|
|
slab_post_alloc_hook(s, flags, size, p);
|
|
/* FIXME: Trace call missing. Christoph would like a bulk variant */
|
|
return size;
|
|
error:
|
|
local_irq_enable();
|
|
cache_alloc_debugcheck_after_bulk(s, flags, i, p, _RET_IP_);
|
|
slab_post_alloc_hook(s, flags, i, p);
|
|
__kmem_cache_free_bulk(s, i, p);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_alloc_bulk);
|
|
|
|
#ifdef CONFIG_TRACING
|
|
void *
|
|
kmem_cache_alloc_trace(struct kmem_cache *cachep, gfp_t flags, size_t size)
|
|
{
|
|
void *ret;
|
|
|
|
ret = slab_alloc(cachep, flags, _RET_IP_);
|
|
|
|
kasan_kmalloc(cachep, ret, size, flags);
|
|
trace_kmalloc(_RET_IP_, ret,
|
|
size, cachep->size, flags);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_alloc_trace);
|
|
#endif
|
|
|
|
#ifdef CONFIG_NUMA
|
|
/**
|
|
* kmem_cache_alloc_node - Allocate an object on the specified node
|
|
* @cachep: The cache to allocate from.
|
|
* @flags: See kmalloc().
|
|
* @nodeid: node number of the target node.
|
|
*
|
|
* Identical to kmem_cache_alloc 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.
|
|
*/
|
|
void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
|
|
{
|
|
void *ret = slab_alloc_node(cachep, flags, nodeid, _RET_IP_);
|
|
|
|
kasan_slab_alloc(cachep, ret, flags);
|
|
trace_kmem_cache_alloc_node(_RET_IP_, ret,
|
|
cachep->object_size, cachep->size,
|
|
flags, nodeid);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_alloc_node);
|
|
|
|
#ifdef CONFIG_TRACING
|
|
void *kmem_cache_alloc_node_trace(struct kmem_cache *cachep,
|
|
gfp_t flags,
|
|
int nodeid,
|
|
size_t size)
|
|
{
|
|
void *ret;
|
|
|
|
ret = slab_alloc_node(cachep, flags, nodeid, _RET_IP_);
|
|
|
|
kasan_kmalloc(cachep, ret, size, flags);
|
|
trace_kmalloc_node(_RET_IP_, ret,
|
|
size, cachep->size,
|
|
flags, nodeid);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_alloc_node_trace);
|
|
#endif
|
|
|
|
static __always_inline void *
|
|
__do_kmalloc_node(size_t size, gfp_t flags, int node, unsigned long caller)
|
|
{
|
|
struct kmem_cache *cachep;
|
|
void *ret;
|
|
|
|
cachep = kmalloc_slab(size, flags);
|
|
if (unlikely(ZERO_OR_NULL_PTR(cachep)))
|
|
return cachep;
|
|
ret = kmem_cache_alloc_node_trace(cachep, flags, node, size);
|
|
kasan_kmalloc(cachep, ret, size, flags);
|
|
|
|
return ret;
|
|
}
|
|
|
|
void *__kmalloc_node(size_t size, gfp_t flags, int node)
|
|
{
|
|
return __do_kmalloc_node(size, flags, node, _RET_IP_);
|
|
}
|
|
EXPORT_SYMBOL(__kmalloc_node);
|
|
|
|
void *__kmalloc_node_track_caller(size_t size, gfp_t flags,
|
|
int node, unsigned long caller)
|
|
{
|
|
return __do_kmalloc_node(size, flags, node, caller);
|
|
}
|
|
EXPORT_SYMBOL(__kmalloc_node_track_caller);
|
|
#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,
|
|
unsigned long caller)
|
|
{
|
|
struct kmem_cache *cachep;
|
|
void *ret;
|
|
|
|
cachep = kmalloc_slab(size, flags);
|
|
if (unlikely(ZERO_OR_NULL_PTR(cachep)))
|
|
return cachep;
|
|
ret = slab_alloc(cachep, flags, caller);
|
|
|
|
kasan_kmalloc(cachep, ret, size, flags);
|
|
trace_kmalloc(caller, ret,
|
|
size, cachep->size, flags);
|
|
|
|
return ret;
|
|
}
|
|
|
|
void *__kmalloc(size_t size, gfp_t flags)
|
|
{
|
|
return __do_kmalloc(size, flags, _RET_IP_);
|
|
}
|
|
EXPORT_SYMBOL(__kmalloc);
|
|
|
|
void *__kmalloc_track_caller(size_t size, gfp_t flags, unsigned long caller)
|
|
{
|
|
return __do_kmalloc(size, flags, caller);
|
|
}
|
|
EXPORT_SYMBOL(__kmalloc_track_caller);
|
|
|
|
/**
|
|
* 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;
|
|
cachep = cache_from_obj(cachep, objp);
|
|
if (!cachep)
|
|
return;
|
|
|
|
local_irq_save(flags);
|
|
debug_check_no_locks_freed(objp, cachep->object_size);
|
|
if (!(cachep->flags & SLAB_DEBUG_OBJECTS))
|
|
debug_check_no_obj_freed(objp, cachep->object_size);
|
|
__cache_free(cachep, objp, _RET_IP_);
|
|
local_irq_restore(flags);
|
|
|
|
trace_kmem_cache_free(_RET_IP_, objp);
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_free);
|
|
|
|
void kmem_cache_free_bulk(struct kmem_cache *orig_s, size_t size, void **p)
|
|
{
|
|
struct kmem_cache *s;
|
|
size_t i;
|
|
|
|
local_irq_disable();
|
|
for (i = 0; i < size; i++) {
|
|
void *objp = p[i];
|
|
|
|
if (!orig_s) /* called via kfree_bulk */
|
|
s = virt_to_cache(objp);
|
|
else
|
|
s = cache_from_obj(orig_s, objp);
|
|
|
|
debug_check_no_locks_freed(objp, s->object_size);
|
|
if (!(s->flags & SLAB_DEBUG_OBJECTS))
|
|
debug_check_no_obj_freed(objp, s->object_size);
|
|
|
|
__cache_free(s, objp, _RET_IP_);
|
|
}
|
|
local_irq_enable();
|
|
|
|
/* FIXME: add tracing */
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_free_bulk);
|
|
|
|
/**
|
|
* 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;
|
|
|
|
trace_kfree(_RET_IP_, objp);
|
|
|
|
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, c->object_size);
|
|
|
|
debug_check_no_obj_freed(objp, c->object_size);
|
|
__cache_free(c, (void *)objp, _RET_IP_);
|
|
local_irq_restore(flags);
|
|
}
|
|
EXPORT_SYMBOL(kfree);
|
|
|
|
/*
|
|
* This initializes kmem_cache_node or resizes various caches for all nodes.
|
|
*/
|
|
static int setup_kmem_cache_nodes(struct kmem_cache *cachep, gfp_t gfp)
|
|
{
|
|
int ret;
|
|
int node;
|
|
struct kmem_cache_node *n;
|
|
|
|
for_each_online_node(node) {
|
|
ret = setup_kmem_cache_node(cachep, node, gfp, true);
|
|
if (ret)
|
|
goto fail;
|
|
|
|
}
|
|
|
|
return 0;
|
|
|
|
fail:
|
|
if (!cachep->list.next) {
|
|
/* Cache is not active yet. Roll back what we did */
|
|
node--;
|
|
while (node >= 0) {
|
|
n = get_node(cachep, node);
|
|
if (n) {
|
|
kfree(n->shared);
|
|
free_alien_cache(n->alien);
|
|
kfree(n);
|
|
cachep->node[node] = NULL;
|
|
}
|
|
node--;
|
|
}
|
|
}
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/* Always called with the slab_mutex held */
|
|
static int __do_tune_cpucache(struct kmem_cache *cachep, int limit,
|
|
int batchcount, int shared, gfp_t gfp)
|
|
{
|
|
struct array_cache __percpu *cpu_cache, *prev;
|
|
int cpu;
|
|
|
|
cpu_cache = alloc_kmem_cache_cpus(cachep, limit, batchcount);
|
|
if (!cpu_cache)
|
|
return -ENOMEM;
|
|
|
|
prev = cachep->cpu_cache;
|
|
cachep->cpu_cache = cpu_cache;
|
|
kick_all_cpus_sync();
|
|
|
|
check_irq_on();
|
|
cachep->batchcount = batchcount;
|
|
cachep->limit = limit;
|
|
cachep->shared = shared;
|
|
|
|
if (!prev)
|
|
goto setup_node;
|
|
|
|
for_each_online_cpu(cpu) {
|
|
LIST_HEAD(list);
|
|
int node;
|
|
struct kmem_cache_node *n;
|
|
struct array_cache *ac = per_cpu_ptr(prev, cpu);
|
|
|
|
node = cpu_to_mem(cpu);
|
|
n = get_node(cachep, node);
|
|
spin_lock_irq(&n->list_lock);
|
|
free_block(cachep, ac->entry, ac->avail, node, &list);
|
|
spin_unlock_irq(&n->list_lock);
|
|
slabs_destroy(cachep, &list);
|
|
}
|
|
free_percpu(prev);
|
|
|
|
setup_node:
|
|
return setup_kmem_cache_nodes(cachep, gfp);
|
|
}
|
|
|
|
static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
|
|
int batchcount, int shared, gfp_t gfp)
|
|
{
|
|
int ret;
|
|
struct kmem_cache *c;
|
|
|
|
ret = __do_tune_cpucache(cachep, limit, batchcount, shared, gfp);
|
|
|
|
if (slab_state < FULL)
|
|
return ret;
|
|
|
|
if ((ret < 0) || !is_root_cache(cachep))
|
|
return ret;
|
|
|
|
lockdep_assert_held(&slab_mutex);
|
|
for_each_memcg_cache(c, cachep) {
|
|
/* return value determined by the root cache only */
|
|
__do_tune_cpucache(c, limit, batchcount, shared, gfp);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* Called with slab_mutex held always */
|
|
static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp)
|
|
{
|
|
int err;
|
|
int limit = 0;
|
|
int shared = 0;
|
|
int batchcount = 0;
|
|
|
|
err = cache_random_seq_create(cachep, gfp);
|
|
if (err)
|
|
goto end;
|
|
|
|
if (!is_root_cache(cachep)) {
|
|
struct kmem_cache *root = memcg_root_cache(cachep);
|
|
limit = root->limit;
|
|
shared = root->shared;
|
|
batchcount = root->batchcount;
|
|
}
|
|
|
|
if (limit && shared && batchcount)
|
|
goto skip_setup;
|
|
/*
|
|
* 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->size > 131072)
|
|
limit = 1;
|
|
else if (cachep->size > PAGE_SIZE)
|
|
limit = 8;
|
|
else if (cachep->size > 1024)
|
|
limit = 24;
|
|
else if (cachep->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->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
|
|
batchcount = (limit + 1) / 2;
|
|
skip_setup:
|
|
err = do_tune_cpucache(cachep, limit, batchcount, shared, gfp);
|
|
end:
|
|
if (err)
|
|
pr_err("enable_cpucache failed for %s, error %d\n",
|
|
cachep->name, -err);
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Drain an array if it contains any elements taking the node lock only if
|
|
* necessary. Note that the node listlock also protects the array_cache
|
|
* if drain_array() is used on the shared array.
|
|
*/
|
|
static void drain_array(struct kmem_cache *cachep, struct kmem_cache_node *n,
|
|
struct array_cache *ac, int node)
|
|
{
|
|
LIST_HEAD(list);
|
|
|
|
/* ac from n->shared can be freed if we don't hold the slab_mutex. */
|
|
check_mutex_acquired();
|
|
|
|
if (!ac || !ac->avail)
|
|
return;
|
|
|
|
if (ac->touched) {
|
|
ac->touched = 0;
|
|
return;
|
|
}
|
|
|
|
spin_lock_irq(&n->list_lock);
|
|
drain_array_locked(cachep, ac, node, false, &list);
|
|
spin_unlock_irq(&n->list_lock);
|
|
|
|
slabs_destroy(cachep, &list);
|
|
}
|
|
|
|
/**
|
|
* 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_cache_node *n;
|
|
int node = numa_mem_id();
|
|
struct delayed_work *work = to_delayed_work(w);
|
|
|
|
if (!mutex_trylock(&slab_mutex))
|
|
/* Give up. Setup the next iteration. */
|
|
goto out;
|
|
|
|
list_for_each_entry(searchp, &slab_caches, list) {
|
|
check_irq_on();
|
|
|
|
/*
|
|
* We only take the node lock if absolutely necessary and we
|
|
* have established with reasonable certainty that
|
|
* we can do some work if the lock was obtained.
|
|
*/
|
|
n = get_node(searchp, node);
|
|
|
|
reap_alien(searchp, n);
|
|
|
|
drain_array(searchp, n, cpu_cache_get(searchp), node);
|
|
|
|
/*
|
|
* These are racy checks but it does not matter
|
|
* if we skip one check or scan twice.
|
|
*/
|
|
if (time_after(n->next_reap, jiffies))
|
|
goto next;
|
|
|
|
n->next_reap = jiffies + REAPTIMEOUT_NODE;
|
|
|
|
drain_array(searchp, n, n->shared, node);
|
|
|
|
if (n->free_touched)
|
|
n->free_touched = 0;
|
|
else {
|
|
int freed;
|
|
|
|
freed = drain_freelist(searchp, n, (n->free_limit +
|
|
5 * searchp->num - 1) / (5 * searchp->num));
|
|
STATS_ADD_REAPED(searchp, freed);
|
|
}
|
|
next:
|
|
cond_resched();
|
|
}
|
|
check_irq_on();
|
|
mutex_unlock(&slab_mutex);
|
|
next_reap_node();
|
|
out:
|
|
/* Set up the next iteration */
|
|
schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_AC));
|
|
}
|
|
|
|
#ifdef CONFIG_SLABINFO
|
|
void get_slabinfo(struct kmem_cache *cachep, struct slabinfo *sinfo)
|
|
{
|
|
struct page *page;
|
|
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_cache_node *n;
|
|
|
|
active_objs = 0;
|
|
num_slabs = 0;
|
|
for_each_kmem_cache_node(cachep, node, n) {
|
|
|
|
check_irq_on();
|
|
spin_lock_irq(&n->list_lock);
|
|
|
|
list_for_each_entry(page, &n->slabs_full, lru) {
|
|
if (page->active != cachep->num && !error)
|
|
error = "slabs_full accounting error";
|
|
active_objs += cachep->num;
|
|
active_slabs++;
|
|
}
|
|
list_for_each_entry(page, &n->slabs_partial, lru) {
|
|
if (page->active == cachep->num && !error)
|
|
error = "slabs_partial accounting error";
|
|
if (!page->active && !error)
|
|
error = "slabs_partial accounting error";
|
|
active_objs += page->active;
|
|
active_slabs++;
|
|
}
|
|
list_for_each_entry(page, &n->slabs_free, lru) {
|
|
if (page->active && !error)
|
|
error = "slabs_free accounting error";
|
|
num_slabs++;
|
|
}
|
|
free_objects += n->free_objects;
|
|
if (n->shared)
|
|
shared_avail += n->shared->avail;
|
|
|
|
spin_unlock_irq(&n->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)
|
|
pr_err("slab: cache %s error: %s\n", name, error);
|
|
|
|
sinfo->active_objs = active_objs;
|
|
sinfo->num_objs = num_objs;
|
|
sinfo->active_slabs = active_slabs;
|
|
sinfo->num_slabs = num_slabs;
|
|
sinfo->shared_avail = shared_avail;
|
|
sinfo->limit = cachep->limit;
|
|
sinfo->batchcount = cachep->batchcount;
|
|
sinfo->shared = cachep->shared;
|
|
sinfo->objects_per_slab = cachep->num;
|
|
sinfo->cache_order = cachep->gfporder;
|
|
}
|
|
|
|
void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *cachep)
|
|
{
|
|
#if STATS
|
|
{ /* node 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
|
|
}
|
|
|
|
#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(&slab_mutex);
|
|
res = -EINVAL;
|
|
list_for_each_entry(cachep, &slab_caches, list) {
|
|
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,
|
|
GFP_KERNEL);
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
mutex_unlock(&slab_mutex);
|
|
if (res >= 0)
|
|
res = count;
|
|
return res;
|
|
}
|
|
|
|
#ifdef CONFIG_DEBUG_SLAB_LEAK
|
|
|
|
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 page *page)
|
|
{
|
|
void *p;
|
|
int i, j;
|
|
unsigned long v;
|
|
|
|
if (n[0] == n[1])
|
|
return;
|
|
for (i = 0, p = page->s_mem; i < c->num; i++, p += c->size) {
|
|
bool active = true;
|
|
|
|
for (j = page->active; j < c->num; j++) {
|
|
if (get_free_obj(page, j) == i) {
|
|
active = false;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!active)
|
|
continue;
|
|
|
|
/*
|
|
* probe_kernel_read() is used for DEBUG_PAGEALLOC. page table
|
|
* mapping is established when actual object allocation and
|
|
* we could mistakenly access the unmapped object in the cpu
|
|
* cache.
|
|
*/
|
|
if (probe_kernel_read(&v, dbg_userword(c, p), sizeof(v)))
|
|
continue;
|
|
|
|
if (!add_caller(n, v))
|
|
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, list);
|
|
struct page *page;
|
|
struct kmem_cache_node *n;
|
|
const char *name;
|
|
unsigned long *x = m->private;
|
|
int node;
|
|
int i;
|
|
|
|
if (!(cachep->flags & SLAB_STORE_USER))
|
|
return 0;
|
|
if (!(cachep->flags & SLAB_RED_ZONE))
|
|
return 0;
|
|
|
|
/*
|
|
* Set store_user_clean and start to grab stored user information
|
|
* for all objects on this cache. If some alloc/free requests comes
|
|
* during the processing, information would be wrong so restart
|
|
* whole processing.
|
|
*/
|
|
do {
|
|
set_store_user_clean(cachep);
|
|
drain_cpu_caches(cachep);
|
|
|
|
x[1] = 0;
|
|
|
|
for_each_kmem_cache_node(cachep, node, n) {
|
|
|
|
check_irq_on();
|
|
spin_lock_irq(&n->list_lock);
|
|
|
|
list_for_each_entry(page, &n->slabs_full, lru)
|
|
handle_slab(x, cachep, page);
|
|
list_for_each_entry(page, &n->slabs_partial, lru)
|
|
handle_slab(x, cachep, page);
|
|
spin_unlock_irq(&n->list_lock);
|
|
}
|
|
} while (!is_store_user_clean(cachep));
|
|
|
|
name = cachep->name;
|
|
if (x[0] == x[1]) {
|
|
/* Increase the buffer size */
|
|
mutex_unlock(&slab_mutex);
|
|
m->private = kzalloc(x[0] * 4 * sizeof(unsigned long), GFP_KERNEL);
|
|
if (!m->private) {
|
|
/* Too bad, we are really out */
|
|
m->private = x;
|
|
mutex_lock(&slab_mutex);
|
|
return -ENOMEM;
|
|
}
|
|
*(unsigned long *)m->private = x[0] * 2;
|
|
kfree(x);
|
|
mutex_lock(&slab_mutex);
|
|
/* Now make sure this entry will be retried */
|
|
m->count = m->size;
|
|
return 0;
|
|
}
|
|
for (i = 0; i < x[1]; i++) {
|
|
seq_printf(m, "%s: %lu ", name, x[2*i+3]);
|
|
show_symbol(m, x[2*i+2]);
|
|
seq_putc(m, '\n');
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations slabstats_op = {
|
|
.start = slab_start,
|
|
.next = slab_next,
|
|
.stop = slab_stop,
|
|
.show = leaks_show,
|
|
};
|
|
|
|
static int slabstats_open(struct inode *inode, struct file *file)
|
|
{
|
|
unsigned long *n;
|
|
|
|
n = __seq_open_private(file, &slabstats_op, PAGE_SIZE);
|
|
if (!n)
|
|
return -ENOMEM;
|
|
|
|
*n = PAGE_SIZE / (2 * sizeof(unsigned long));
|
|
|
|
return 0;
|
|
}
|
|
|
|
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)
|
|
{
|
|
size_t size;
|
|
|
|
BUG_ON(!objp);
|
|
if (unlikely(objp == ZERO_SIZE_PTR))
|
|
return 0;
|
|
|
|
size = virt_to_cache(objp)->object_size;
|
|
/* We assume that ksize callers could use the whole allocated area,
|
|
* so we need to unpoison this area.
|
|
*/
|
|
kasan_unpoison_shadow(objp, size);
|
|
|
|
return size;
|
|
}
|
|
EXPORT_SYMBOL(ksize);
|