62918a0361
Set use_alien_caches to 0 on non NUMA platforms. And avoid calling the cache_free_alien() when use_alien_caches is not set. This will avoid the cache miss that happens while dereferencing slabp to get nodeid. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Andi Kleen <andi@firstfloor.org> Cc: Eric Dumazet <dada1@cosmosbay.com> Cc: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
4491 lines
116 KiB
C
4491 lines
116 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 intializations 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 'cache_chain_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/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/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 <asm/cacheflush.h>
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#include <asm/tlbflush.h>
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#include <asm/page.h>
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/*
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* DEBUG - 1 for kmem_cache_create() to honour; SLAB_DEBUG_INITIAL,
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* 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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#ifndef cache_line_size
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#define cache_line_size() L1_CACHE_BYTES
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#endif
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#ifndef ARCH_KMALLOC_MINALIGN
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/*
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* Enforce a minimum alignment for the kmalloc caches.
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* Usually, the kmalloc caches are cache_line_size() aligned, except when
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* DEBUG and FORCED_DEBUG are enabled, then they are BYTES_PER_WORD aligned.
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* Some archs want to perform DMA into kmalloc caches and need a guaranteed
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* alignment larger than BYTES_PER_WORD. ARCH_KMALLOC_MINALIGN allows that.
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* Note that this flag disables some debug features.
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*/
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#define ARCH_KMALLOC_MINALIGN 0
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#endif
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#ifndef ARCH_SLAB_MINALIGN
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/*
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* Enforce a minimum alignment for all caches.
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* Intended for archs that get misalignment faults even for BYTES_PER_WORD
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* aligned buffers. Includes ARCH_KMALLOC_MINALIGN.
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* If possible: Do not enable this flag for CONFIG_DEBUG_SLAB, it disables
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* some debug features.
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*/
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#define ARCH_SLAB_MINALIGN 0
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#endif
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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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/* Legal flag mask for kmem_cache_create(). */
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#if DEBUG
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# define CREATE_MASK (SLAB_DEBUG_INITIAL | SLAB_RED_ZONE | \
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SLAB_POISON | SLAB_HWCACHE_ALIGN | \
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SLAB_CACHE_DMA | \
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SLAB_MUST_HWCACHE_ALIGN | SLAB_STORE_USER | \
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SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
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SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD)
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#else
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# define CREATE_MASK (SLAB_HWCACHE_ALIGN | \
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SLAB_CACHE_DMA | SLAB_MUST_HWCACHE_ALIGN | \
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SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
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SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD)
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#endif
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/*
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* kmem_bufctl_t:
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*
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* Bufctl's are used for linking objs within a slab
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* linked offsets.
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*
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* This implementation relies on "struct page" for locating the cache &
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* slab an object belongs to.
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* This allows the bufctl structure to be small (one int), but limits
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* the number of objects a slab (not a cache) can contain when off-slab
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* bufctls are used. The limit is the size of the largest general cache
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* that does not use off-slab slabs.
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* For 32bit archs with 4 kB pages, is this 56.
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* This is not serious, as it is only for large objects, when it is unwise
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* to have too many per slab.
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* Note: This limit can be raised by introducing a general cache whose size
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* is less than 512 (PAGE_SIZE<<3), but greater than 256.
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*/
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typedef unsigned int kmem_bufctl_t;
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#define BUFCTL_END (((kmem_bufctl_t)(~0U))-0)
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#define BUFCTL_FREE (((kmem_bufctl_t)(~0U))-1)
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#define BUFCTL_ACTIVE (((kmem_bufctl_t)(~0U))-2)
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#define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-3)
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/*
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* struct slab
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*
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* Manages the objs in a slab. Placed either at the beginning of mem allocated
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* for a slab, or allocated from an general cache.
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* Slabs are chained into three list: fully used, partial, fully free slabs.
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*/
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struct slab {
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struct list_head list;
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unsigned long colouroff;
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void *s_mem; /* including colour offset */
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unsigned int inuse; /* num of objs active in slab */
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kmem_bufctl_t free;
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unsigned short nodeid;
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};
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/*
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* struct slab_rcu
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*
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* slab_destroy on a SLAB_DESTROY_BY_RCU cache uses this structure to
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* arrange for kmem_freepages to be called via RCU. This is useful if
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* we need to approach a kernel structure obliquely, from its address
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* obtained without the usual locking. We can lock the structure to
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* stabilize it and check it's still at the given address, only if we
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* can be sure that the memory has not been meanwhile reused for some
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* other kind of object (which our subsystem's lock might corrupt).
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*
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* rcu_read_lock before reading the address, then rcu_read_unlock after
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* taking the spinlock within the structure expected at that address.
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*
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* We assume struct slab_rcu can overlay struct slab when destroying.
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*/
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struct slab_rcu {
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struct rcu_head head;
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struct kmem_cache *cachep;
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void *addr;
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};
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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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spinlock_t lock;
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void *entry[0]; /*
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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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* [0] is for gcc 2.95. It should really be [].
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*/
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};
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/*
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* bootstrap: The caches do not work without cpuarrays anymore, but the
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* cpuarrays are allocated from the generic caches...
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*/
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#define BOOT_CPUCACHE_ENTRIES 1
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struct arraycache_init {
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struct array_cache cache;
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void *entries[BOOT_CPUCACHE_ENTRIES];
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};
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/*
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* The slab lists for all objects.
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*/
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struct kmem_list3 {
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struct list_head slabs_partial; /* partial list first, better asm code */
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struct list_head slabs_full;
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struct list_head slabs_free;
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unsigned long free_objects;
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unsigned int free_limit;
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unsigned int colour_next; /* Per-node cache coloring */
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spinlock_t list_lock;
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struct array_cache *shared; /* shared per node */
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struct array_cache **alien; /* on other nodes */
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unsigned long next_reap; /* updated without locking */
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int free_touched; /* updated without locking */
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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 + 1)
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struct kmem_list3 __initdata initkmem_list3[NUM_INIT_LISTS];
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#define CACHE_CACHE 0
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#define SIZE_AC 1
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#define SIZE_L3 (1 + MAX_NUMNODES)
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static int drain_freelist(struct kmem_cache *cache,
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struct kmem_list3 *l3, int tofree);
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static void free_block(struct kmem_cache *cachep, void **objpp, int len,
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int node);
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static int enable_cpucache(struct kmem_cache *cachep);
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static void cache_reap(struct work_struct *unused);
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/*
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* This function must be completely optimized away if a constant is passed to
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* it. Mostly the same as what is in linux/slab.h except it returns an index.
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*/
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static __always_inline int index_of(const size_t size)
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{
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extern void __bad_size(void);
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if (__builtin_constant_p(size)) {
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int i = 0;
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#define CACHE(x) \
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if (size <=x) \
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return i; \
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else \
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i++;
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#include "linux/kmalloc_sizes.h"
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#undef CACHE
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__bad_size();
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} else
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__bad_size();
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return 0;
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}
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|
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static int slab_early_init = 1;
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#define INDEX_AC index_of(sizeof(struct arraycache_init))
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#define INDEX_L3 index_of(sizeof(struct kmem_list3))
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static void kmem_list3_init(struct kmem_list3 *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(&(cachep->nodelists[nodeid]->slab), listp); \
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} while (0)
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|
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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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|
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/*
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* struct kmem_cache
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*
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* manages a cache.
|
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*/
|
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|
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struct kmem_cache {
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/* 1) per-cpu data, touched during every alloc/free */
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struct array_cache *array[NR_CPUS];
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/* 2) Cache tunables. Protected by cache_chain_mutex */
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unsigned int batchcount;
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unsigned int limit;
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unsigned int shared;
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|
|
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unsigned int buffer_size;
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u32 reciprocal_buffer_size;
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/* 3) touched by every alloc & free from the backend */
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struct kmem_list3 *nodelists[MAX_NUMNODES];
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|
|
|
unsigned int flags; /* constant flags */
|
|
unsigned int num; /* # of objs per slab */
|
|
|
|
/* 4) cache_grow/shrink */
|
|
/* order of pgs per slab (2^n) */
|
|
unsigned int gfporder;
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|
|
|
/* force GFP flags, e.g. GFP_DMA */
|
|
gfp_t gfpflags;
|
|
|
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size_t colour; /* cache colouring range */
|
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unsigned int colour_off; /* colour offset */
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struct kmem_cache *slabp_cache;
|
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unsigned int slab_size;
|
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unsigned int dflags; /* dynamic flags */
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|
|
|
/* constructor func */
|
|
void (*ctor) (void *, struct kmem_cache *, unsigned long);
|
|
|
|
/* de-constructor func */
|
|
void (*dtor) (void *, struct kmem_cache *, unsigned long);
|
|
|
|
/* 5) cache creation/removal */
|
|
const char *name;
|
|
struct list_head next;
|
|
|
|
/* 6) statistics */
|
|
#if STATS
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|
unsigned long num_active;
|
|
unsigned long num_allocations;
|
|
unsigned long high_mark;
|
|
unsigned long grown;
|
|
unsigned long reaped;
|
|
unsigned long errors;
|
|
unsigned long max_freeable;
|
|
unsigned long node_allocs;
|
|
unsigned long node_frees;
|
|
unsigned long node_overflow;
|
|
atomic_t allochit;
|
|
atomic_t allocmiss;
|
|
atomic_t freehit;
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|
atomic_t freemiss;
|
|
#endif
|
|
#if DEBUG
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|
/*
|
|
* If debugging is enabled, then the allocator can add additional
|
|
* fields and/or padding to every object. buffer_size contains the total
|
|
* object size including these internal fields, the following two
|
|
* variables contain the offset to the user object and its size.
|
|
*/
|
|
int obj_offset;
|
|
int obj_size;
|
|
#endif
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|
};
|
|
|
|
#define CFLGS_OFF_SLAB (0x80000000UL)
|
|
#define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB)
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|
|
|
#define BATCHREFILL_LIMIT 16
|
|
/*
|
|
* Optimization question: fewer reaps means less probability for unnessary
|
|
* cpucache drain/refill cycles.
|
|
*
|
|
* OTOH the cpuarrays can contain lots of objects,
|
|
* which could lock up otherwise freeable slabs.
|
|
*/
|
|
#define REAPTIMEOUT_CPUC (2*HZ)
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|
#define REAPTIMEOUT_LIST3 (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--)
|
|
#define STATS_INC_ALLOCED(x) ((x)->num_allocations++)
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|
#define STATS_INC_GROWN(x) ((x)->grown++)
|
|
#define STATS_ADD_REAPED(x,y) ((x)->reaped += (y))
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|
#define STATS_SET_HIGH(x) \
|
|
do { \
|
|
if ((x)->num_active > (x)->high_mark) \
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|
(x)->high_mark = (x)->num_active; \
|
|
} while (0)
|
|
#define STATS_INC_ERR(x) ((x)->errors++)
|
|
#define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++)
|
|
#define STATS_INC_NODEFREES(x) ((x)->node_frees++)
|
|
#define STATS_INC_ACOVERFLOW(x) ((x)->node_overflow++)
|
|
#define STATS_SET_FREEABLE(x, i) \
|
|
do { \
|
|
if ((x)->max_freeable < i) \
|
|
(x)->max_freeable = i; \
|
|
} while (0)
|
|
#define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit)
|
|
#define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss)
|
|
#define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit)
|
|
#define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss)
|
|
#else
|
|
#define STATS_INC_ACTIVE(x) do { } while (0)
|
|
#define STATS_DEC_ACTIVE(x) do { } while (0)
|
|
#define STATS_INC_ALLOCED(x) do { } while (0)
|
|
#define STATS_INC_GROWN(x) do { } while (0)
|
|
#define STATS_ADD_REAPED(x,y) do { } while (0)
|
|
#define STATS_SET_HIGH(x) do { } while (0)
|
|
#define STATS_INC_ERR(x) do { } while (0)
|
|
#define STATS_INC_NODEALLOCS(x) do { } while (0)
|
|
#define STATS_INC_NODEFREES(x) do { } while (0)
|
|
#define STATS_INC_ACOVERFLOW(x) do { } while (0)
|
|
#define STATS_SET_FREEABLE(x, i) do { } while (0)
|
|
#define STATS_INC_ALLOCHIT(x) do { } while (0)
|
|
#define STATS_INC_ALLOCMISS(x) do { } while (0)
|
|
#define STATS_INC_FREEHIT(x) do { } while (0)
|
|
#define STATS_INC_FREEMISS(x) do { } while (0)
|
|
#endif
|
|
|
|
#if DEBUG
|
|
|
|
/*
|
|
* memory layout of objects:
|
|
* 0 : objp
|
|
* 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that
|
|
* the end of an object is aligned with the end of the real
|
|
* allocation. Catches writes behind the end of the allocation.
|
|
* cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1:
|
|
* redzone word.
|
|
* cachep->obj_offset: The real object.
|
|
* cachep->buffer_size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long]
|
|
* cachep->buffer_size - 1* BYTES_PER_WORD: last caller address
|
|
* [BYTES_PER_WORD long]
|
|
*/
|
|
static int obj_offset(struct kmem_cache *cachep)
|
|
{
|
|
return cachep->obj_offset;
|
|
}
|
|
|
|
static int obj_size(struct kmem_cache *cachep)
|
|
{
|
|
return cachep->obj_size;
|
|
}
|
|
|
|
static unsigned long *dbg_redzone1(struct kmem_cache *cachep, void *objp)
|
|
{
|
|
BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
|
|
return (unsigned long*) (objp+obj_offset(cachep)-BYTES_PER_WORD);
|
|
}
|
|
|
|
static unsigned long *dbg_redzone2(struct kmem_cache *cachep, void *objp)
|
|
{
|
|
BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
|
|
if (cachep->flags & SLAB_STORE_USER)
|
|
return (unsigned long *)(objp + cachep->buffer_size -
|
|
2 * BYTES_PER_WORD);
|
|
return (unsigned long *)(objp + cachep->buffer_size - BYTES_PER_WORD);
|
|
}
|
|
|
|
static void **dbg_userword(struct kmem_cache *cachep, void *objp)
|
|
{
|
|
BUG_ON(!(cachep->flags & SLAB_STORE_USER));
|
|
return (void **)(objp + cachep->buffer_size - BYTES_PER_WORD);
|
|
}
|
|
|
|
#else
|
|
|
|
#define obj_offset(x) 0
|
|
#define obj_size(cachep) (cachep->buffer_size)
|
|
#define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long *)NULL;})
|
|
#define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long *)NULL;})
|
|
#define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;})
|
|
|
|
#endif
|
|
|
|
/*
|
|
* Maximum size of an obj (in 2^order pages) and absolute limit for the gfp
|
|
* order.
|
|
*/
|
|
#if defined(CONFIG_LARGE_ALLOCS)
|
|
#define MAX_OBJ_ORDER 13 /* up to 32Mb */
|
|
#define MAX_GFP_ORDER 13 /* up to 32Mb */
|
|
#elif defined(CONFIG_MMU)
|
|
#define MAX_OBJ_ORDER 5 /* 32 pages */
|
|
#define MAX_GFP_ORDER 5 /* 32 pages */
|
|
#else
|
|
#define MAX_OBJ_ORDER 8 /* up to 1Mb */
|
|
#define MAX_GFP_ORDER 8 /* up to 1Mb */
|
|
#endif
|
|
|
|
/*
|
|
* Do not go above this order unless 0 objects fit into the slab.
|
|
*/
|
|
#define BREAK_GFP_ORDER_HI 1
|
|
#define BREAK_GFP_ORDER_LO 0
|
|
static int slab_break_gfp_order = BREAK_GFP_ORDER_LO;
|
|
|
|
/*
|
|
* Functions for storing/retrieving the cachep and or slab from the page
|
|
* allocator. These are used to find the slab an obj belongs to. With kfree(),
|
|
* these are used to find the cache which an obj belongs to.
|
|
*/
|
|
static inline void page_set_cache(struct page *page, struct kmem_cache *cache)
|
|
{
|
|
page->lru.next = (struct list_head *)cache;
|
|
}
|
|
|
|
static inline struct kmem_cache *page_get_cache(struct page *page)
|
|
{
|
|
if (unlikely(PageCompound(page)))
|
|
page = (struct page *)page_private(page);
|
|
BUG_ON(!PageSlab(page));
|
|
return (struct kmem_cache *)page->lru.next;
|
|
}
|
|
|
|
static inline void page_set_slab(struct page *page, struct slab *slab)
|
|
{
|
|
page->lru.prev = (struct list_head *)slab;
|
|
}
|
|
|
|
static inline struct slab *page_get_slab(struct page *page)
|
|
{
|
|
if (unlikely(PageCompound(page)))
|
|
page = (struct page *)page_private(page);
|
|
BUG_ON(!PageSlab(page));
|
|
return (struct slab *)page->lru.prev;
|
|
}
|
|
|
|
static inline struct kmem_cache *virt_to_cache(const void *obj)
|
|
{
|
|
struct page *page = virt_to_page(obj);
|
|
return page_get_cache(page);
|
|
}
|
|
|
|
static inline struct slab *virt_to_slab(const void *obj)
|
|
{
|
|
struct page *page = virt_to_page(obj);
|
|
return page_get_slab(page);
|
|
}
|
|
|
|
static inline void *index_to_obj(struct kmem_cache *cache, struct slab *slab,
|
|
unsigned int idx)
|
|
{
|
|
return slab->s_mem + cache->buffer_size * idx;
|
|
}
|
|
|
|
/*
|
|
* We want to avoid an expensive divide : (offset / cache->buffer_size)
|
|
* Using the fact that buffer_size is a constant for a particular cache,
|
|
* we can replace (offset / cache->buffer_size) by
|
|
* reciprocal_divide(offset, cache->reciprocal_buffer_size)
|
|
*/
|
|
static inline unsigned int obj_to_index(const struct kmem_cache *cache,
|
|
const struct slab *slab, void *obj)
|
|
{
|
|
u32 offset = (obj - slab->s_mem);
|
|
return reciprocal_divide(offset, cache->reciprocal_buffer_size);
|
|
}
|
|
|
|
/*
|
|
* These are the default caches for kmalloc. Custom caches can have other sizes.
|
|
*/
|
|
struct cache_sizes malloc_sizes[] = {
|
|
#define CACHE(x) { .cs_size = (x) },
|
|
#include <linux/kmalloc_sizes.h>
|
|
CACHE(ULONG_MAX)
|
|
#undef CACHE
|
|
};
|
|
EXPORT_SYMBOL(malloc_sizes);
|
|
|
|
/* Must match cache_sizes above. Out of line to keep cache footprint low. */
|
|
struct cache_names {
|
|
char *name;
|
|
char *name_dma;
|
|
};
|
|
|
|
static struct cache_names __initdata cache_names[] = {
|
|
#define CACHE(x) { .name = "size-" #x, .name_dma = "size-" #x "(DMA)" },
|
|
#include <linux/kmalloc_sizes.h>
|
|
{NULL,}
|
|
#undef CACHE
|
|
};
|
|
|
|
static struct arraycache_init initarray_cache __initdata =
|
|
{ {0, BOOT_CPUCACHE_ENTRIES, 1, 0} };
|
|
static struct arraycache_init initarray_generic =
|
|
{ {0, BOOT_CPUCACHE_ENTRIES, 1, 0} };
|
|
|
|
/* internal cache of cache description objs */
|
|
static struct kmem_cache cache_cache = {
|
|
.batchcount = 1,
|
|
.limit = BOOT_CPUCACHE_ENTRIES,
|
|
.shared = 1,
|
|
.buffer_size = sizeof(struct kmem_cache),
|
|
.name = "kmem_cache",
|
|
#if DEBUG
|
|
.obj_size = sizeof(struct kmem_cache),
|
|
#endif
|
|
};
|
|
|
|
#define BAD_ALIEN_MAGIC 0x01020304ul
|
|
|
|
#ifdef CONFIG_LOCKDEP
|
|
|
|
/*
|
|
* Slab sometimes uses the kmalloc slabs to store the slab headers
|
|
* for other slabs "off slab".
|
|
* The locking for this is tricky in that it nests within the locks
|
|
* of all other slabs in a few places; to deal with this special
|
|
* locking we put on-slab caches into a separate lock-class.
|
|
*
|
|
* We set lock class for alien array caches which are up during init.
|
|
* The lock annotation will be lost if all cpus of a node goes down and
|
|
* then comes back up during hotplug
|
|
*/
|
|
static struct lock_class_key on_slab_l3_key;
|
|
static struct lock_class_key on_slab_alc_key;
|
|
|
|
static inline void init_lock_keys(void)
|
|
|
|
{
|
|
int q;
|
|
struct cache_sizes *s = malloc_sizes;
|
|
|
|
while (s->cs_size != ULONG_MAX) {
|
|
for_each_node(q) {
|
|
struct array_cache **alc;
|
|
int r;
|
|
struct kmem_list3 *l3 = s->cs_cachep->nodelists[q];
|
|
if (!l3 || OFF_SLAB(s->cs_cachep))
|
|
continue;
|
|
lockdep_set_class(&l3->list_lock, &on_slab_l3_key);
|
|
alc = l3->alien;
|
|
/*
|
|
* FIXME: This check for BAD_ALIEN_MAGIC
|
|
* should go away when common slab code is taught to
|
|
* work even without alien caches.
|
|
* Currently, non NUMA code returns BAD_ALIEN_MAGIC
|
|
* for alloc_alien_cache,
|
|
*/
|
|
if (!alc || (unsigned long)alc == BAD_ALIEN_MAGIC)
|
|
continue;
|
|
for_each_node(r) {
|
|
if (alc[r])
|
|
lockdep_set_class(&alc[r]->lock,
|
|
&on_slab_alc_key);
|
|
}
|
|
}
|
|
s++;
|
|
}
|
|
}
|
|
#else
|
|
static inline void init_lock_keys(void)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* 1. Guard access to the cache-chain.
|
|
* 2. Protect sanity of cpu_online_map against cpu hotplug events
|
|
*/
|
|
static DEFINE_MUTEX(cache_chain_mutex);
|
|
static struct list_head cache_chain;
|
|
|
|
/*
|
|
* chicken and egg problem: delay the per-cpu array allocation
|
|
* until the general caches are up.
|
|
*/
|
|
static enum {
|
|
NONE,
|
|
PARTIAL_AC,
|
|
PARTIAL_L3,
|
|
FULL
|
|
} g_cpucache_up;
|
|
|
|
/*
|
|
* used by boot code to determine if it can use slab based allocator
|
|
*/
|
|
int slab_is_available(void)
|
|
{
|
|
return g_cpucache_up == FULL;
|
|
}
|
|
|
|
static DEFINE_PER_CPU(struct delayed_work, reap_work);
|
|
|
|
static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep)
|
|
{
|
|
return cachep->array[smp_processor_id()];
|
|
}
|
|
|
|
static inline struct kmem_cache *__find_general_cachep(size_t size,
|
|
gfp_t gfpflags)
|
|
{
|
|
struct cache_sizes *csizep = malloc_sizes;
|
|
|
|
#if DEBUG
|
|
/* This happens if someone tries to call
|
|
* kmem_cache_create(), or __kmalloc(), before
|
|
* the generic caches are initialized.
|
|
*/
|
|
BUG_ON(malloc_sizes[INDEX_AC].cs_cachep == NULL);
|
|
#endif
|
|
while (size > csizep->cs_size)
|
|
csizep++;
|
|
|
|
/*
|
|
* Really subtle: The last entry with cs->cs_size==ULONG_MAX
|
|
* has cs_{dma,}cachep==NULL. Thus no special case
|
|
* for large kmalloc calls required.
|
|
*/
|
|
#ifdef CONFIG_ZONE_DMA
|
|
if (unlikely(gfpflags & GFP_DMA))
|
|
return csizep->cs_dmacachep;
|
|
#endif
|
|
return csizep->cs_cachep;
|
|
}
|
|
|
|
static struct kmem_cache *kmem_find_general_cachep(size_t size, gfp_t gfpflags)
|
|
{
|
|
return __find_general_cachep(size, gfpflags);
|
|
}
|
|
|
|
static size_t slab_mgmt_size(size_t nr_objs, size_t align)
|
|
{
|
|
return ALIGN(sizeof(struct slab)+nr_objs*sizeof(kmem_bufctl_t), align);
|
|
}
|
|
|
|
/*
|
|
* Calculate the number of objects and left-over bytes for a given buffer size.
|
|
*/
|
|
static void cache_estimate(unsigned long gfporder, size_t buffer_size,
|
|
size_t align, int flags, size_t *left_over,
|
|
unsigned int *num)
|
|
{
|
|
int nr_objs;
|
|
size_t mgmt_size;
|
|
size_t slab_size = PAGE_SIZE << gfporder;
|
|
|
|
/*
|
|
* The slab management structure can be either off the slab or
|
|
* on it. For the latter case, the memory allocated for a
|
|
* slab is used for:
|
|
*
|
|
* - The struct slab
|
|
* - One kmem_bufctl_t for each object
|
|
* - Padding to respect alignment of @align
|
|
* - @buffer_size bytes for each object
|
|
*
|
|
* If the slab management structure is off the slab, then the
|
|
* alignment will already be calculated into the size. Because
|
|
* the slabs are all pages aligned, the objects will be at the
|
|
* correct alignment when allocated.
|
|
*/
|
|
if (flags & CFLGS_OFF_SLAB) {
|
|
mgmt_size = 0;
|
|
nr_objs = slab_size / buffer_size;
|
|
|
|
if (nr_objs > SLAB_LIMIT)
|
|
nr_objs = SLAB_LIMIT;
|
|
} else {
|
|
/*
|
|
* Ignore padding for the initial guess. The padding
|
|
* is at most @align-1 bytes, and @buffer_size is at
|
|
* least @align. In the worst case, this result will
|
|
* be one greater than the number of objects that fit
|
|
* into the memory allocation when taking the padding
|
|
* into account.
|
|
*/
|
|
nr_objs = (slab_size - sizeof(struct slab)) /
|
|
(buffer_size + sizeof(kmem_bufctl_t));
|
|
|
|
/*
|
|
* This calculated number will be either the right
|
|
* amount, or one greater than what we want.
|
|
*/
|
|
if (slab_mgmt_size(nr_objs, align) + nr_objs*buffer_size
|
|
> slab_size)
|
|
nr_objs--;
|
|
|
|
if (nr_objs > SLAB_LIMIT)
|
|
nr_objs = SLAB_LIMIT;
|
|
|
|
mgmt_size = slab_mgmt_size(nr_objs, align);
|
|
}
|
|
*num = nr_objs;
|
|
*left_over = slab_size - nr_objs*buffer_size - mgmt_size;
|
|
}
|
|
|
|
#define slab_error(cachep, msg) __slab_error(__FUNCTION__, cachep, msg)
|
|
|
|
static void __slab_error(const char *function, struct kmem_cache *cachep,
|
|
char *msg)
|
|
{
|
|
printk(KERN_ERR "slab error in %s(): cache `%s': %s\n",
|
|
function, cachep->name, msg);
|
|
dump_stack();
|
|
}
|
|
|
|
/*
|
|
* By default on NUMA we use alien caches to stage the freeing of
|
|
* objects allocated from other nodes. This causes massive memory
|
|
* inefficiencies when using fake NUMA setup to split memory into a
|
|
* large number of small nodes, so it can be disabled on the command
|
|
* line
|
|
*/
|
|
|
|
static int use_alien_caches __read_mostly = 1;
|
|
static int __init noaliencache_setup(char *s)
|
|
{
|
|
use_alien_caches = 0;
|
|
return 1;
|
|
}
|
|
__setup("noaliencache", noaliencache_setup);
|
|
|
|
#ifdef CONFIG_NUMA
|
|
/*
|
|
* Special reaping functions for NUMA systems called from cache_reap().
|
|
* These take care of doing round robin flushing of alien caches (containing
|
|
* objects freed on different nodes from which they were allocated) and the
|
|
* flushing of remote pcps by calling drain_node_pages.
|
|
*/
|
|
static DEFINE_PER_CPU(unsigned long, reap_node);
|
|
|
|
static void init_reap_node(int cpu)
|
|
{
|
|
int node;
|
|
|
|
node = next_node(cpu_to_node(cpu), node_online_map);
|
|
if (node == MAX_NUMNODES)
|
|
node = first_node(node_online_map);
|
|
|
|
per_cpu(reap_node, cpu) = node;
|
|
}
|
|
|
|
static void next_reap_node(void)
|
|
{
|
|
int node = __get_cpu_var(reap_node);
|
|
|
|
/*
|
|
* Also drain per cpu pages on remote zones
|
|
*/
|
|
if (node != numa_node_id())
|
|
drain_node_pages(node);
|
|
|
|
node = next_node(node, node_online_map);
|
|
if (unlikely(node >= MAX_NUMNODES))
|
|
node = first_node(node_online_map);
|
|
__get_cpu_var(reap_node) = node;
|
|
}
|
|
|
|
#else
|
|
#define init_reap_node(cpu) do { } while (0)
|
|
#define next_reap_node(void) do { } while (0)
|
|
#endif
|
|
|
|
/*
|
|
* Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz
|
|
* via the workqueue/eventd.
|
|
* Add the CPU number into the expiration time to minimize the possibility of
|
|
* the CPUs getting into lockstep and contending for the global cache chain
|
|
* lock.
|
|
*/
|
|
static void __devinit start_cpu_timer(int cpu)
|
|
{
|
|
struct delayed_work *reap_work = &per_cpu(reap_work, cpu);
|
|
|
|
/*
|
|
* When this gets called from do_initcalls via cpucache_init(),
|
|
* init_workqueues() has already run, so keventd will be setup
|
|
* at that time.
|
|
*/
|
|
if (keventd_up() && reap_work->work.func == NULL) {
|
|
init_reap_node(cpu);
|
|
INIT_DELAYED_WORK(reap_work, cache_reap);
|
|
schedule_delayed_work_on(cpu, reap_work,
|
|
__round_jiffies_relative(HZ, cpu));
|
|
}
|
|
}
|
|
|
|
static struct array_cache *alloc_arraycache(int node, int entries,
|
|
int batchcount)
|
|
{
|
|
int memsize = sizeof(void *) * entries + sizeof(struct array_cache);
|
|
struct array_cache *nc = NULL;
|
|
|
|
nc = kmalloc_node(memsize, GFP_KERNEL, node);
|
|
if (nc) {
|
|
nc->avail = 0;
|
|
nc->limit = entries;
|
|
nc->batchcount = batchcount;
|
|
nc->touched = 0;
|
|
spin_lock_init(&nc->lock);
|
|
}
|
|
return nc;
|
|
}
|
|
|
|
/*
|
|
* Transfer objects in one arraycache to another.
|
|
* Locking must be handled by the caller.
|
|
*
|
|
* Return the number of entries transferred.
|
|
*/
|
|
static int transfer_objects(struct array_cache *to,
|
|
struct array_cache *from, unsigned int max)
|
|
{
|
|
/* Figure out how many entries to transfer */
|
|
int nr = min(min(from->avail, max), to->limit - to->avail);
|
|
|
|
if (!nr)
|
|
return 0;
|
|
|
|
memcpy(to->entry + to->avail, from->entry + from->avail -nr,
|
|
sizeof(void *) *nr);
|
|
|
|
from->avail -= nr;
|
|
to->avail += nr;
|
|
to->touched = 1;
|
|
return nr;
|
|
}
|
|
|
|
#ifndef CONFIG_NUMA
|
|
|
|
#define drain_alien_cache(cachep, alien) do { } while (0)
|
|
#define reap_alien(cachep, l3) do { } while (0)
|
|
|
|
static inline struct array_cache **alloc_alien_cache(int node, int limit)
|
|
{
|
|
return (struct array_cache **)BAD_ALIEN_MAGIC;
|
|
}
|
|
|
|
static inline void free_alien_cache(struct array_cache **ac_ptr)
|
|
{
|
|
}
|
|
|
|
static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline void *alternate_node_alloc(struct kmem_cache *cachep,
|
|
gfp_t flags)
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
static inline void *____cache_alloc_node(struct kmem_cache *cachep,
|
|
gfp_t flags, int nodeid)
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
#else /* CONFIG_NUMA */
|
|
|
|
static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int);
|
|
static void *alternate_node_alloc(struct kmem_cache *, gfp_t);
|
|
|
|
static struct array_cache **alloc_alien_cache(int node, int limit)
|
|
{
|
|
struct array_cache **ac_ptr;
|
|
int memsize = sizeof(void *) * nr_node_ids;
|
|
int i;
|
|
|
|
if (limit > 1)
|
|
limit = 12;
|
|
ac_ptr = kmalloc_node(memsize, GFP_KERNEL, node);
|
|
if (ac_ptr) {
|
|
for_each_node(i) {
|
|
if (i == node || !node_online(i)) {
|
|
ac_ptr[i] = NULL;
|
|
continue;
|
|
}
|
|
ac_ptr[i] = alloc_arraycache(node, limit, 0xbaadf00d);
|
|
if (!ac_ptr[i]) {
|
|
for (i--; i <= 0; i--)
|
|
kfree(ac_ptr[i]);
|
|
kfree(ac_ptr);
|
|
return NULL;
|
|
}
|
|
}
|
|
}
|
|
return ac_ptr;
|
|
}
|
|
|
|
static void free_alien_cache(struct array_cache **ac_ptr)
|
|
{
|
|
int i;
|
|
|
|
if (!ac_ptr)
|
|
return;
|
|
for_each_node(i)
|
|
kfree(ac_ptr[i]);
|
|
kfree(ac_ptr);
|
|
}
|
|
|
|
static void __drain_alien_cache(struct kmem_cache *cachep,
|
|
struct array_cache *ac, int node)
|
|
{
|
|
struct kmem_list3 *rl3 = cachep->nodelists[node];
|
|
|
|
if (ac->avail) {
|
|
spin_lock(&rl3->list_lock);
|
|
/*
|
|
* Stuff objects into the remote nodes shared array first.
|
|
* That way we could avoid the overhead of putting the objects
|
|
* into the free lists and getting them back later.
|
|
*/
|
|
if (rl3->shared)
|
|
transfer_objects(rl3->shared, ac, ac->limit);
|
|
|
|
free_block(cachep, ac->entry, ac->avail, node);
|
|
ac->avail = 0;
|
|
spin_unlock(&rl3->list_lock);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Called from cache_reap() to regularly drain alien caches round robin.
|
|
*/
|
|
static void reap_alien(struct kmem_cache *cachep, struct kmem_list3 *l3)
|
|
{
|
|
int node = __get_cpu_var(reap_node);
|
|
|
|
if (l3->alien) {
|
|
struct array_cache *ac = l3->alien[node];
|
|
|
|
if (ac && ac->avail && spin_trylock_irq(&ac->lock)) {
|
|
__drain_alien_cache(cachep, ac, node);
|
|
spin_unlock_irq(&ac->lock);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void drain_alien_cache(struct kmem_cache *cachep,
|
|
struct array_cache **alien)
|
|
{
|
|
int i = 0;
|
|
struct array_cache *ac;
|
|
unsigned long flags;
|
|
|
|
for_each_online_node(i) {
|
|
ac = alien[i];
|
|
if (ac) {
|
|
spin_lock_irqsave(&ac->lock, flags);
|
|
__drain_alien_cache(cachep, ac, i);
|
|
spin_unlock_irqrestore(&ac->lock, flags);
|
|
}
|
|
}
|
|
}
|
|
|
|
static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
|
|
{
|
|
struct slab *slabp = virt_to_slab(objp);
|
|
int nodeid = slabp->nodeid;
|
|
struct kmem_list3 *l3;
|
|
struct array_cache *alien = NULL;
|
|
int node;
|
|
|
|
node = numa_node_id();
|
|
|
|
/*
|
|
* Make sure we are not freeing a object from another node to the array
|
|
* cache on this cpu.
|
|
*/
|
|
if (likely(slabp->nodeid == node))
|
|
return 0;
|
|
|
|
l3 = cachep->nodelists[node];
|
|
STATS_INC_NODEFREES(cachep);
|
|
if (l3->alien && l3->alien[nodeid]) {
|
|
alien = l3->alien[nodeid];
|
|
spin_lock(&alien->lock);
|
|
if (unlikely(alien->avail == alien->limit)) {
|
|
STATS_INC_ACOVERFLOW(cachep);
|
|
__drain_alien_cache(cachep, alien, nodeid);
|
|
}
|
|
alien->entry[alien->avail++] = objp;
|
|
spin_unlock(&alien->lock);
|
|
} else {
|
|
spin_lock(&(cachep->nodelists[nodeid])->list_lock);
|
|
free_block(cachep, &objp, 1, nodeid);
|
|
spin_unlock(&(cachep->nodelists[nodeid])->list_lock);
|
|
}
|
|
return 1;
|
|
}
|
|
#endif
|
|
|
|
static int __cpuinit cpuup_callback(struct notifier_block *nfb,
|
|
unsigned long action, void *hcpu)
|
|
{
|
|
long cpu = (long)hcpu;
|
|
struct kmem_cache *cachep;
|
|
struct kmem_list3 *l3 = NULL;
|
|
int node = cpu_to_node(cpu);
|
|
int memsize = sizeof(struct kmem_list3);
|
|
|
|
switch (action) {
|
|
case CPU_UP_PREPARE:
|
|
mutex_lock(&cache_chain_mutex);
|
|
/*
|
|
* We need to do this right in the beginning since
|
|
* alloc_arraycache's are going to use this list.
|
|
* kmalloc_node allows us to add the slab to the right
|
|
* kmem_list3 and not this cpu's kmem_list3
|
|
*/
|
|
|
|
list_for_each_entry(cachep, &cache_chain, next) {
|
|
/*
|
|
* Set up the size64 kmemlist for cpu before we can
|
|
* begin anything. Make sure some other cpu on this
|
|
* node has not already allocated this
|
|
*/
|
|
if (!cachep->nodelists[node]) {
|
|
l3 = kmalloc_node(memsize, GFP_KERNEL, node);
|
|
if (!l3)
|
|
goto bad;
|
|
kmem_list3_init(l3);
|
|
l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
|
|
((unsigned long)cachep) % REAPTIMEOUT_LIST3;
|
|
|
|
/*
|
|
* The l3s don't come and go as CPUs come and
|
|
* go. cache_chain_mutex is sufficient
|
|
* protection here.
|
|
*/
|
|
cachep->nodelists[node] = l3;
|
|
}
|
|
|
|
spin_lock_irq(&cachep->nodelists[node]->list_lock);
|
|
cachep->nodelists[node]->free_limit =
|
|
(1 + nr_cpus_node(node)) *
|
|
cachep->batchcount + cachep->num;
|
|
spin_unlock_irq(&cachep->nodelists[node]->list_lock);
|
|
}
|
|
|
|
/*
|
|
* Now we can go ahead with allocating the shared arrays and
|
|
* array caches
|
|
*/
|
|
list_for_each_entry(cachep, &cache_chain, next) {
|
|
struct array_cache *nc;
|
|
struct array_cache *shared;
|
|
struct array_cache **alien = NULL;
|
|
|
|
nc = alloc_arraycache(node, cachep->limit,
|
|
cachep->batchcount);
|
|
if (!nc)
|
|
goto bad;
|
|
shared = alloc_arraycache(node,
|
|
cachep->shared * cachep->batchcount,
|
|
0xbaadf00d);
|
|
if (!shared)
|
|
goto bad;
|
|
|
|
if (use_alien_caches) {
|
|
alien = alloc_alien_cache(node, cachep->limit);
|
|
if (!alien)
|
|
goto bad;
|
|
}
|
|
cachep->array[cpu] = nc;
|
|
l3 = cachep->nodelists[node];
|
|
BUG_ON(!l3);
|
|
|
|
spin_lock_irq(&l3->list_lock);
|
|
if (!l3->shared) {
|
|
/*
|
|
* We are serialised from CPU_DEAD or
|
|
* CPU_UP_CANCELLED by the cpucontrol lock
|
|
*/
|
|
l3->shared = shared;
|
|
shared = NULL;
|
|
}
|
|
#ifdef CONFIG_NUMA
|
|
if (!l3->alien) {
|
|
l3->alien = alien;
|
|
alien = NULL;
|
|
}
|
|
#endif
|
|
spin_unlock_irq(&l3->list_lock);
|
|
kfree(shared);
|
|
free_alien_cache(alien);
|
|
}
|
|
break;
|
|
case CPU_ONLINE:
|
|
mutex_unlock(&cache_chain_mutex);
|
|
start_cpu_timer(cpu);
|
|
break;
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
case CPU_DOWN_PREPARE:
|
|
mutex_lock(&cache_chain_mutex);
|
|
break;
|
|
case CPU_DOWN_FAILED:
|
|
mutex_unlock(&cache_chain_mutex);
|
|
break;
|
|
case CPU_DEAD:
|
|
/*
|
|
* Even if all the cpus of a node are down, we don't free the
|
|
* kmem_list3 of any cache. This to avoid a race between
|
|
* cpu_down, and a kmalloc allocation from another cpu for
|
|
* memory from the node of the cpu going down. The list3
|
|
* structure is usually allocated from kmem_cache_create() and
|
|
* gets destroyed at kmem_cache_destroy().
|
|
*/
|
|
/* fall thru */
|
|
#endif
|
|
case CPU_UP_CANCELED:
|
|
list_for_each_entry(cachep, &cache_chain, next) {
|
|
struct array_cache *nc;
|
|
struct array_cache *shared;
|
|
struct array_cache **alien;
|
|
cpumask_t mask;
|
|
|
|
mask = node_to_cpumask(node);
|
|
/* cpu is dead; no one can alloc from it. */
|
|
nc = cachep->array[cpu];
|
|
cachep->array[cpu] = NULL;
|
|
l3 = cachep->nodelists[node];
|
|
|
|
if (!l3)
|
|
goto free_array_cache;
|
|
|
|
spin_lock_irq(&l3->list_lock);
|
|
|
|
/* Free limit for this kmem_list3 */
|
|
l3->free_limit -= cachep->batchcount;
|
|
if (nc)
|
|
free_block(cachep, nc->entry, nc->avail, node);
|
|
|
|
if (!cpus_empty(mask)) {
|
|
spin_unlock_irq(&l3->list_lock);
|
|
goto free_array_cache;
|
|
}
|
|
|
|
shared = l3->shared;
|
|
if (shared) {
|
|
free_block(cachep, l3->shared->entry,
|
|
l3->shared->avail, node);
|
|
l3->shared = NULL;
|
|
}
|
|
|
|
alien = l3->alien;
|
|
l3->alien = NULL;
|
|
|
|
spin_unlock_irq(&l3->list_lock);
|
|
|
|
kfree(shared);
|
|
if (alien) {
|
|
drain_alien_cache(cachep, alien);
|
|
free_alien_cache(alien);
|
|
}
|
|
free_array_cache:
|
|
kfree(nc);
|
|
}
|
|
/*
|
|
* In the previous loop, all the objects were freed to
|
|
* the respective cache's slabs, now we can go ahead and
|
|
* shrink each nodelist to its limit.
|
|
*/
|
|
list_for_each_entry(cachep, &cache_chain, next) {
|
|
l3 = cachep->nodelists[node];
|
|
if (!l3)
|
|
continue;
|
|
drain_freelist(cachep, l3, l3->free_objects);
|
|
}
|
|
mutex_unlock(&cache_chain_mutex);
|
|
break;
|
|
}
|
|
return NOTIFY_OK;
|
|
bad:
|
|
return NOTIFY_BAD;
|
|
}
|
|
|
|
static struct notifier_block __cpuinitdata cpucache_notifier = {
|
|
&cpuup_callback, NULL, 0
|
|
};
|
|
|
|
/*
|
|
* swap the static kmem_list3 with kmalloced memory
|
|
*/
|
|
static void init_list(struct kmem_cache *cachep, struct kmem_list3 *list,
|
|
int nodeid)
|
|
{
|
|
struct kmem_list3 *ptr;
|
|
|
|
ptr = kmalloc_node(sizeof(struct kmem_list3), GFP_KERNEL, nodeid);
|
|
BUG_ON(!ptr);
|
|
|
|
local_irq_disable();
|
|
memcpy(ptr, list, sizeof(struct kmem_list3));
|
|
/*
|
|
* Do not assume that spinlocks can be initialized via memcpy:
|
|
*/
|
|
spin_lock_init(&ptr->list_lock);
|
|
|
|
MAKE_ALL_LISTS(cachep, ptr, nodeid);
|
|
cachep->nodelists[nodeid] = ptr;
|
|
local_irq_enable();
|
|
}
|
|
|
|
/*
|
|
* Initialisation. Called after the page allocator have been initialised and
|
|
* before smp_init().
|
|
*/
|
|
void __init kmem_cache_init(void)
|
|
{
|
|
size_t left_over;
|
|
struct cache_sizes *sizes;
|
|
struct cache_names *names;
|
|
int i;
|
|
int order;
|
|
int node;
|
|
|
|
if (num_possible_nodes() == 1)
|
|
use_alien_caches = 0;
|
|
|
|
for (i = 0; i < NUM_INIT_LISTS; i++) {
|
|
kmem_list3_init(&initkmem_list3[i]);
|
|
if (i < MAX_NUMNODES)
|
|
cache_cache.nodelists[i] = NULL;
|
|
}
|
|
|
|
/*
|
|
* Fragmentation resistance on low memory - only use bigger
|
|
* page orders on machines with more than 32MB of memory.
|
|
*/
|
|
if (num_physpages > (32 << 20) >> PAGE_SHIFT)
|
|
slab_break_gfp_order = BREAK_GFP_ORDER_HI;
|
|
|
|
/* Bootstrap is tricky, because several objects are allocated
|
|
* from caches that do not exist yet:
|
|
* 1) initialize the cache_cache cache: it contains the struct
|
|
* kmem_cache structures of all caches, except cache_cache itself:
|
|
* cache_cache is statically allocated.
|
|
* Initially an __init data area is used for the head array and the
|
|
* kmem_list3 structures, it's replaced with a kmalloc allocated
|
|
* array at the end of the bootstrap.
|
|
* 2) Create the first kmalloc cache.
|
|
* The struct kmem_cache for the new cache is allocated normally.
|
|
* An __init data area is used for the head array.
|
|
* 3) Create the remaining kmalloc caches, with minimally sized
|
|
* head arrays.
|
|
* 4) Replace the __init data head arrays for cache_cache and the first
|
|
* kmalloc cache with kmalloc allocated arrays.
|
|
* 5) Replace the __init data for kmem_list3 for cache_cache and
|
|
* the other cache's with kmalloc allocated memory.
|
|
* 6) Resize the head arrays of the kmalloc caches to their final sizes.
|
|
*/
|
|
|
|
node = numa_node_id();
|
|
|
|
/* 1) create the cache_cache */
|
|
INIT_LIST_HEAD(&cache_chain);
|
|
list_add(&cache_cache.next, &cache_chain);
|
|
cache_cache.colour_off = cache_line_size();
|
|
cache_cache.array[smp_processor_id()] = &initarray_cache.cache;
|
|
cache_cache.nodelists[node] = &initkmem_list3[CACHE_CACHE];
|
|
|
|
cache_cache.buffer_size = ALIGN(cache_cache.buffer_size,
|
|
cache_line_size());
|
|
cache_cache.reciprocal_buffer_size =
|
|
reciprocal_value(cache_cache.buffer_size);
|
|
|
|
for (order = 0; order < MAX_ORDER; order++) {
|
|
cache_estimate(order, cache_cache.buffer_size,
|
|
cache_line_size(), 0, &left_over, &cache_cache.num);
|
|
if (cache_cache.num)
|
|
break;
|
|
}
|
|
BUG_ON(!cache_cache.num);
|
|
cache_cache.gfporder = order;
|
|
cache_cache.colour = left_over / cache_cache.colour_off;
|
|
cache_cache.slab_size = ALIGN(cache_cache.num * sizeof(kmem_bufctl_t) +
|
|
sizeof(struct slab), cache_line_size());
|
|
|
|
/* 2+3) create the kmalloc caches */
|
|
sizes = malloc_sizes;
|
|
names = cache_names;
|
|
|
|
/*
|
|
* Initialize the caches that provide memory for the array cache and the
|
|
* kmem_list3 structures first. Without this, further allocations will
|
|
* bug.
|
|
*/
|
|
|
|
sizes[INDEX_AC].cs_cachep = kmem_cache_create(names[INDEX_AC].name,
|
|
sizes[INDEX_AC].cs_size,
|
|
ARCH_KMALLOC_MINALIGN,
|
|
ARCH_KMALLOC_FLAGS|SLAB_PANIC,
|
|
NULL, NULL);
|
|
|
|
if (INDEX_AC != INDEX_L3) {
|
|
sizes[INDEX_L3].cs_cachep =
|
|
kmem_cache_create(names[INDEX_L3].name,
|
|
sizes[INDEX_L3].cs_size,
|
|
ARCH_KMALLOC_MINALIGN,
|
|
ARCH_KMALLOC_FLAGS|SLAB_PANIC,
|
|
NULL, NULL);
|
|
}
|
|
|
|
slab_early_init = 0;
|
|
|
|
while (sizes->cs_size != ULONG_MAX) {
|
|
/*
|
|
* For performance, all the general caches are L1 aligned.
|
|
* This should be particularly beneficial on SMP boxes, as it
|
|
* eliminates "false sharing".
|
|
* Note for systems short on memory removing the alignment will
|
|
* allow tighter packing of the smaller caches.
|
|
*/
|
|
if (!sizes->cs_cachep) {
|
|
sizes->cs_cachep = kmem_cache_create(names->name,
|
|
sizes->cs_size,
|
|
ARCH_KMALLOC_MINALIGN,
|
|
ARCH_KMALLOC_FLAGS|SLAB_PANIC,
|
|
NULL, NULL);
|
|
}
|
|
#ifdef CONFIG_ZONE_DMA
|
|
sizes->cs_dmacachep = kmem_cache_create(
|
|
names->name_dma,
|
|
sizes->cs_size,
|
|
ARCH_KMALLOC_MINALIGN,
|
|
ARCH_KMALLOC_FLAGS|SLAB_CACHE_DMA|
|
|
SLAB_PANIC,
|
|
NULL, NULL);
|
|
#endif
|
|
sizes++;
|
|
names++;
|
|
}
|
|
/* 4) Replace the bootstrap head arrays */
|
|
{
|
|
struct array_cache *ptr;
|
|
|
|
ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
|
|
|
|
local_irq_disable();
|
|
BUG_ON(cpu_cache_get(&cache_cache) != &initarray_cache.cache);
|
|
memcpy(ptr, cpu_cache_get(&cache_cache),
|
|
sizeof(struct arraycache_init));
|
|
/*
|
|
* Do not assume that spinlocks can be initialized via memcpy:
|
|
*/
|
|
spin_lock_init(&ptr->lock);
|
|
|
|
cache_cache.array[smp_processor_id()] = ptr;
|
|
local_irq_enable();
|
|
|
|
ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
|
|
|
|
local_irq_disable();
|
|
BUG_ON(cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep)
|
|
!= &initarray_generic.cache);
|
|
memcpy(ptr, cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep),
|
|
sizeof(struct arraycache_init));
|
|
/*
|
|
* Do not assume that spinlocks can be initialized via memcpy:
|
|
*/
|
|
spin_lock_init(&ptr->lock);
|
|
|
|
malloc_sizes[INDEX_AC].cs_cachep->array[smp_processor_id()] =
|
|
ptr;
|
|
local_irq_enable();
|
|
}
|
|
/* 5) Replace the bootstrap kmem_list3's */
|
|
{
|
|
int nid;
|
|
|
|
/* Replace the static kmem_list3 structures for the boot cpu */
|
|
init_list(&cache_cache, &initkmem_list3[CACHE_CACHE], node);
|
|
|
|
for_each_online_node(nid) {
|
|
init_list(malloc_sizes[INDEX_AC].cs_cachep,
|
|
&initkmem_list3[SIZE_AC + nid], nid);
|
|
|
|
if (INDEX_AC != INDEX_L3) {
|
|
init_list(malloc_sizes[INDEX_L3].cs_cachep,
|
|
&initkmem_list3[SIZE_L3 + nid], nid);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* 6) resize the head arrays to their final sizes */
|
|
{
|
|
struct kmem_cache *cachep;
|
|
mutex_lock(&cache_chain_mutex);
|
|
list_for_each_entry(cachep, &cache_chain, next)
|
|
if (enable_cpucache(cachep))
|
|
BUG();
|
|
mutex_unlock(&cache_chain_mutex);
|
|
}
|
|
|
|
/* Annotate slab for lockdep -- annotate the malloc caches */
|
|
init_lock_keys();
|
|
|
|
|
|
/* Done! */
|
|
g_cpucache_up = FULL;
|
|
|
|
/*
|
|
* Register a cpu startup notifier callback that initializes
|
|
* cpu_cache_get for all new cpus
|
|
*/
|
|
register_cpu_notifier(&cpucache_notifier);
|
|
|
|
/*
|
|
* The reap timers are started later, with a module init call: That part
|
|
* of the kernel is not yet operational.
|
|
*/
|
|
}
|
|
|
|
static int __init cpucache_init(void)
|
|
{
|
|
int cpu;
|
|
|
|
/*
|
|
* Register the timers that return unneeded pages to the page allocator
|
|
*/
|
|
for_each_online_cpu(cpu)
|
|
start_cpu_timer(cpu);
|
|
return 0;
|
|
}
|
|
__initcall(cpucache_init);
|
|
|
|
/*
|
|
* Interface to system's page allocator. No need to hold the cache-lock.
|
|
*
|
|
* If we requested dmaable memory, we will get it. Even if we
|
|
* did not request dmaable memory, we might get it, but that
|
|
* would be relatively rare and ignorable.
|
|
*/
|
|
static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
|
|
{
|
|
struct page *page;
|
|
int nr_pages;
|
|
int i;
|
|
|
|
#ifndef CONFIG_MMU
|
|
/*
|
|
* Nommu uses slab's for process anonymous memory allocations, and thus
|
|
* requires __GFP_COMP to properly refcount higher order allocations
|
|
*/
|
|
flags |= __GFP_COMP;
|
|
#endif
|
|
|
|
flags |= cachep->gfpflags;
|
|
|
|
page = alloc_pages_node(nodeid, flags, cachep->gfporder);
|
|
if (!page)
|
|
return NULL;
|
|
|
|
nr_pages = (1 << cachep->gfporder);
|
|
if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
|
|
add_zone_page_state(page_zone(page),
|
|
NR_SLAB_RECLAIMABLE, nr_pages);
|
|
else
|
|
add_zone_page_state(page_zone(page),
|
|
NR_SLAB_UNRECLAIMABLE, nr_pages);
|
|
for (i = 0; i < nr_pages; i++)
|
|
__SetPageSlab(page + i);
|
|
return page_address(page);
|
|
}
|
|
|
|
/*
|
|
* Interface to system's page release.
|
|
*/
|
|
static void kmem_freepages(struct kmem_cache *cachep, void *addr)
|
|
{
|
|
unsigned long i = (1 << cachep->gfporder);
|
|
struct page *page = virt_to_page(addr);
|
|
const unsigned long nr_freed = i;
|
|
|
|
if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
|
|
sub_zone_page_state(page_zone(page),
|
|
NR_SLAB_RECLAIMABLE, nr_freed);
|
|
else
|
|
sub_zone_page_state(page_zone(page),
|
|
NR_SLAB_UNRECLAIMABLE, nr_freed);
|
|
while (i--) {
|
|
BUG_ON(!PageSlab(page));
|
|
__ClearPageSlab(page);
|
|
page++;
|
|
}
|
|
if (current->reclaim_state)
|
|
current->reclaim_state->reclaimed_slab += nr_freed;
|
|
free_pages((unsigned long)addr, cachep->gfporder);
|
|
}
|
|
|
|
static void kmem_rcu_free(struct rcu_head *head)
|
|
{
|
|
struct slab_rcu *slab_rcu = (struct slab_rcu *)head;
|
|
struct kmem_cache *cachep = slab_rcu->cachep;
|
|
|
|
kmem_freepages(cachep, slab_rcu->addr);
|
|
if (OFF_SLAB(cachep))
|
|
kmem_cache_free(cachep->slabp_cache, slab_rcu);
|
|
}
|
|
|
|
#if DEBUG
|
|
|
|
#ifdef CONFIG_DEBUG_PAGEALLOC
|
|
static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr,
|
|
unsigned long caller)
|
|
{
|
|
int size = obj_size(cachep);
|
|
|
|
addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)];
|
|
|
|
if (size < 5 * sizeof(unsigned long))
|
|
return;
|
|
|
|
*addr++ = 0x12345678;
|
|
*addr++ = caller;
|
|
*addr++ = smp_processor_id();
|
|
size -= 3 * sizeof(unsigned long);
|
|
{
|
|
unsigned long *sptr = &caller;
|
|
unsigned long svalue;
|
|
|
|
while (!kstack_end(sptr)) {
|
|
svalue = *sptr++;
|
|
if (kernel_text_address(svalue)) {
|
|
*addr++ = svalue;
|
|
size -= sizeof(unsigned long);
|
|
if (size <= sizeof(unsigned long))
|
|
break;
|
|
}
|
|
}
|
|
|
|
}
|
|
*addr++ = 0x87654321;
|
|
}
|
|
#endif
|
|
|
|
static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val)
|
|
{
|
|
int size = obj_size(cachep);
|
|
addr = &((char *)addr)[obj_offset(cachep)];
|
|
|
|
memset(addr, val, size);
|
|
*(unsigned char *)(addr + size - 1) = POISON_END;
|
|
}
|
|
|
|
static void dump_line(char *data, int offset, int limit)
|
|
{
|
|
int i;
|
|
unsigned char error = 0;
|
|
int bad_count = 0;
|
|
|
|
printk(KERN_ERR "%03x:", offset);
|
|
for (i = 0; i < limit; i++) {
|
|
if (data[offset + i] != POISON_FREE) {
|
|
error = data[offset + i];
|
|
bad_count++;
|
|
}
|
|
printk(" %02x", (unsigned char)data[offset + i]);
|
|
}
|
|
printk("\n");
|
|
|
|
if (bad_count == 1) {
|
|
error ^= POISON_FREE;
|
|
if (!(error & (error - 1))) {
|
|
printk(KERN_ERR "Single bit error detected. Probably "
|
|
"bad RAM.\n");
|
|
#ifdef CONFIG_X86
|
|
printk(KERN_ERR "Run memtest86+ or a similar memory "
|
|
"test tool.\n");
|
|
#else
|
|
printk(KERN_ERR "Run a memory test tool.\n");
|
|
#endif
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if DEBUG
|
|
|
|
static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines)
|
|
{
|
|
int i, size;
|
|
char *realobj;
|
|
|
|
if (cachep->flags & SLAB_RED_ZONE) {
|
|
printk(KERN_ERR "Redzone: 0x%lx/0x%lx.\n",
|
|
*dbg_redzone1(cachep, objp),
|
|
*dbg_redzone2(cachep, objp));
|
|
}
|
|
|
|
if (cachep->flags & SLAB_STORE_USER) {
|
|
printk(KERN_ERR "Last user: [<%p>]",
|
|
*dbg_userword(cachep, objp));
|
|
print_symbol("(%s)",
|
|
(unsigned long)*dbg_userword(cachep, objp));
|
|
printk("\n");
|
|
}
|
|
realobj = (char *)objp + obj_offset(cachep);
|
|
size = obj_size(cachep);
|
|
for (i = 0; i < size && lines; i += 16, lines--) {
|
|
int limit;
|
|
limit = 16;
|
|
if (i + limit > size)
|
|
limit = size - i;
|
|
dump_line(realobj, i, limit);
|
|
}
|
|
}
|
|
|
|
static void check_poison_obj(struct kmem_cache *cachep, void *objp)
|
|
{
|
|
char *realobj;
|
|
int size, i;
|
|
int lines = 0;
|
|
|
|
realobj = (char *)objp + obj_offset(cachep);
|
|
size = obj_size(cachep);
|
|
|
|
for (i = 0; i < size; i++) {
|
|
char exp = POISON_FREE;
|
|
if (i == size - 1)
|
|
exp = POISON_END;
|
|
if (realobj[i] != exp) {
|
|
int limit;
|
|
/* Mismatch ! */
|
|
/* Print header */
|
|
if (lines == 0) {
|
|
printk(KERN_ERR
|
|
"Slab corruption: %s start=%p, len=%d\n",
|
|
cachep->name, realobj, size);
|
|
print_objinfo(cachep, objp, 0);
|
|
}
|
|
/* Hexdump the affected line */
|
|
i = (i / 16) * 16;
|
|
limit = 16;
|
|
if (i + limit > size)
|
|
limit = size - i;
|
|
dump_line(realobj, i, limit);
|
|
i += 16;
|
|
lines++;
|
|
/* Limit to 5 lines */
|
|
if (lines > 5)
|
|
break;
|
|
}
|
|
}
|
|
if (lines != 0) {
|
|
/* Print some data about the neighboring objects, if they
|
|
* exist:
|
|
*/
|
|
struct slab *slabp = virt_to_slab(objp);
|
|
unsigned int objnr;
|
|
|
|
objnr = obj_to_index(cachep, slabp, objp);
|
|
if (objnr) {
|
|
objp = index_to_obj(cachep, slabp, objnr - 1);
|
|
realobj = (char *)objp + obj_offset(cachep);
|
|
printk(KERN_ERR "Prev obj: start=%p, len=%d\n",
|
|
realobj, size);
|
|
print_objinfo(cachep, objp, 2);
|
|
}
|
|
if (objnr + 1 < cachep->num) {
|
|
objp = index_to_obj(cachep, slabp, objnr + 1);
|
|
realobj = (char *)objp + obj_offset(cachep);
|
|
printk(KERN_ERR "Next obj: start=%p, len=%d\n",
|
|
realobj, size);
|
|
print_objinfo(cachep, objp, 2);
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if DEBUG
|
|
/**
|
|
* slab_destroy_objs - destroy a slab and its objects
|
|
* @cachep: cache pointer being destroyed
|
|
* @slabp: slab pointer being destroyed
|
|
*
|
|
* Call the registered destructor for each object in a slab that is being
|
|
* destroyed.
|
|
*/
|
|
static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp)
|
|
{
|
|
int i;
|
|
for (i = 0; i < cachep->num; i++) {
|
|
void *objp = index_to_obj(cachep, slabp, i);
|
|
|
|
if (cachep->flags & SLAB_POISON) {
|
|
#ifdef CONFIG_DEBUG_PAGEALLOC
|
|
if (cachep->buffer_size % PAGE_SIZE == 0 &&
|
|
OFF_SLAB(cachep))
|
|
kernel_map_pages(virt_to_page(objp),
|
|
cachep->buffer_size / PAGE_SIZE, 1);
|
|
else
|
|
check_poison_obj(cachep, objp);
|
|
#else
|
|
check_poison_obj(cachep, objp);
|
|
#endif
|
|
}
|
|
if (cachep->flags & SLAB_RED_ZONE) {
|
|
if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
|
|
slab_error(cachep, "start of a freed object "
|
|
"was overwritten");
|
|
if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
|
|
slab_error(cachep, "end of a freed object "
|
|
"was overwritten");
|
|
}
|
|
if (cachep->dtor && !(cachep->flags & SLAB_POISON))
|
|
(cachep->dtor) (objp + obj_offset(cachep), cachep, 0);
|
|
}
|
|
}
|
|
#else
|
|
static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp)
|
|
{
|
|
if (cachep->dtor) {
|
|
int i;
|
|
for (i = 0; i < cachep->num; i++) {
|
|
void *objp = index_to_obj(cachep, slabp, i);
|
|
(cachep->dtor) (objp, cachep, 0);
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
* slab_destroy - destroy and release all objects in a slab
|
|
* @cachep: cache pointer being destroyed
|
|
* @slabp: slab pointer being destroyed
|
|
*
|
|
* Destroy all the objs in a slab, and release the mem back to the system.
|
|
* Before calling the slab must have been unlinked from the cache. The
|
|
* cache-lock is not held/needed.
|
|
*/
|
|
static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp)
|
|
{
|
|
void *addr = slabp->s_mem - slabp->colouroff;
|
|
|
|
slab_destroy_objs(cachep, slabp);
|
|
if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) {
|
|
struct slab_rcu *slab_rcu;
|
|
|
|
slab_rcu = (struct slab_rcu *)slabp;
|
|
slab_rcu->cachep = cachep;
|
|
slab_rcu->addr = addr;
|
|
call_rcu(&slab_rcu->head, kmem_rcu_free);
|
|
} else {
|
|
kmem_freepages(cachep, addr);
|
|
if (OFF_SLAB(cachep))
|
|
kmem_cache_free(cachep->slabp_cache, slabp);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* For setting up all the kmem_list3s for cache whose buffer_size is same as
|
|
* size of kmem_list3.
|
|
*/
|
|
static void set_up_list3s(struct kmem_cache *cachep, int index)
|
|
{
|
|
int node;
|
|
|
|
for_each_online_node(node) {
|
|
cachep->nodelists[node] = &initkmem_list3[index + node];
|
|
cachep->nodelists[node]->next_reap = jiffies +
|
|
REAPTIMEOUT_LIST3 +
|
|
((unsigned long)cachep) % REAPTIMEOUT_LIST3;
|
|
}
|
|
}
|
|
|
|
static void __kmem_cache_destroy(struct kmem_cache *cachep)
|
|
{
|
|
int i;
|
|
struct kmem_list3 *l3;
|
|
|
|
for_each_online_cpu(i)
|
|
kfree(cachep->array[i]);
|
|
|
|
/* NUMA: free the list3 structures */
|
|
for_each_online_node(i) {
|
|
l3 = cachep->nodelists[i];
|
|
if (l3) {
|
|
kfree(l3->shared);
|
|
free_alien_cache(l3->alien);
|
|
kfree(l3);
|
|
}
|
|
}
|
|
kmem_cache_free(&cache_cache, cachep);
|
|
}
|
|
|
|
|
|
/**
|
|
* calculate_slab_order - calculate size (page order) of slabs
|
|
* @cachep: pointer to the cache that is being created
|
|
* @size: size of objects to be created in this cache.
|
|
* @align: required alignment for the objects.
|
|
* @flags: slab allocation flags
|
|
*
|
|
* Also calculates the number of objects per slab.
|
|
*
|
|
* This could be made much more intelligent. For now, try to avoid using
|
|
* high order pages for slabs. When the gfp() functions are more friendly
|
|
* towards high-order requests, this should be changed.
|
|
*/
|
|
static size_t calculate_slab_order(struct kmem_cache *cachep,
|
|
size_t size, size_t align, unsigned long flags)
|
|
{
|
|
unsigned long offslab_limit;
|
|
size_t left_over = 0;
|
|
int gfporder;
|
|
|
|
for (gfporder = 0; gfporder <= MAX_GFP_ORDER; gfporder++) {
|
|
unsigned int num;
|
|
size_t remainder;
|
|
|
|
cache_estimate(gfporder, size, align, flags, &remainder, &num);
|
|
if (!num)
|
|
continue;
|
|
|
|
if (flags & CFLGS_OFF_SLAB) {
|
|
/*
|
|
* Max number of objs-per-slab for caches which
|
|
* use off-slab slabs. Needed to avoid a possible
|
|
* looping condition in cache_grow().
|
|
*/
|
|
offslab_limit = size - sizeof(struct slab);
|
|
offslab_limit /= sizeof(kmem_bufctl_t);
|
|
|
|
if (num > offslab_limit)
|
|
break;
|
|
}
|
|
|
|
/* Found something acceptable - save it away */
|
|
cachep->num = num;
|
|
cachep->gfporder = gfporder;
|
|
left_over = remainder;
|
|
|
|
/*
|
|
* A VFS-reclaimable slab tends to have most allocations
|
|
* as GFP_NOFS and we really don't want to have to be allocating
|
|
* higher-order pages when we are unable to shrink dcache.
|
|
*/
|
|
if (flags & SLAB_RECLAIM_ACCOUNT)
|
|
break;
|
|
|
|
/*
|
|
* Large number of objects is good, but very large slabs are
|
|
* currently bad for the gfp()s.
|
|
*/
|
|
if (gfporder >= slab_break_gfp_order)
|
|
break;
|
|
|
|
/*
|
|
* Acceptable internal fragmentation?
|
|
*/
|
|
if (left_over * 8 <= (PAGE_SIZE << gfporder))
|
|
break;
|
|
}
|
|
return left_over;
|
|
}
|
|
|
|
static int setup_cpu_cache(struct kmem_cache *cachep)
|
|
{
|
|
if (g_cpucache_up == FULL)
|
|
return enable_cpucache(cachep);
|
|
|
|
if (g_cpucache_up == NONE) {
|
|
/*
|
|
* Note: the first kmem_cache_create must create the cache
|
|
* that's used by kmalloc(24), otherwise the creation of
|
|
* further caches will BUG().
|
|
*/
|
|
cachep->array[smp_processor_id()] = &initarray_generic.cache;
|
|
|
|
/*
|
|
* If the cache that's used by kmalloc(sizeof(kmem_list3)) is
|
|
* the first cache, then we need to set up all its list3s,
|
|
* otherwise the creation of further caches will BUG().
|
|
*/
|
|
set_up_list3s(cachep, SIZE_AC);
|
|
if (INDEX_AC == INDEX_L3)
|
|
g_cpucache_up = PARTIAL_L3;
|
|
else
|
|
g_cpucache_up = PARTIAL_AC;
|
|
} else {
|
|
cachep->array[smp_processor_id()] =
|
|
kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);
|
|
|
|
if (g_cpucache_up == PARTIAL_AC) {
|
|
set_up_list3s(cachep, SIZE_L3);
|
|
g_cpucache_up = PARTIAL_L3;
|
|
} else {
|
|
int node;
|
|
for_each_online_node(node) {
|
|
cachep->nodelists[node] =
|
|
kmalloc_node(sizeof(struct kmem_list3),
|
|
GFP_KERNEL, node);
|
|
BUG_ON(!cachep->nodelists[node]);
|
|
kmem_list3_init(cachep->nodelists[node]);
|
|
}
|
|
}
|
|
}
|
|
cachep->nodelists[numa_node_id()]->next_reap =
|
|
jiffies + REAPTIMEOUT_LIST3 +
|
|
((unsigned long)cachep) % REAPTIMEOUT_LIST3;
|
|
|
|
cpu_cache_get(cachep)->avail = 0;
|
|
cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES;
|
|
cpu_cache_get(cachep)->batchcount = 1;
|
|
cpu_cache_get(cachep)->touched = 0;
|
|
cachep->batchcount = 1;
|
|
cachep->limit = BOOT_CPUCACHE_ENTRIES;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* kmem_cache_create - Create a cache.
|
|
* @name: A string which is used in /proc/slabinfo to identify this cache.
|
|
* @size: The size of objects to be created in this cache.
|
|
* @align: The required alignment for the objects.
|
|
* @flags: SLAB flags
|
|
* @ctor: A constructor for the objects.
|
|
* @dtor: A destructor for the objects.
|
|
*
|
|
* Returns a ptr to the cache on success, NULL on failure.
|
|
* Cannot be called within a int, but can be interrupted.
|
|
* The @ctor is run when new pages are allocated by the cache
|
|
* and the @dtor is run before the pages are handed back.
|
|
*
|
|
* @name must be valid until the cache is destroyed. This implies that
|
|
* the module calling this has to destroy the cache before getting unloaded.
|
|
*
|
|
* The flags are
|
|
*
|
|
* %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
|
|
* to catch references to uninitialised memory.
|
|
*
|
|
* %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
|
|
* for buffer overruns.
|
|
*
|
|
* %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
|
|
* cacheline. This can be beneficial if you're counting cycles as closely
|
|
* as davem.
|
|
*/
|
|
struct kmem_cache *
|
|
kmem_cache_create (const char *name, size_t size, size_t align,
|
|
unsigned long flags,
|
|
void (*ctor)(void*, struct kmem_cache *, unsigned long),
|
|
void (*dtor)(void*, struct kmem_cache *, unsigned long))
|
|
{
|
|
size_t left_over, slab_size, ralign;
|
|
struct kmem_cache *cachep = NULL, *pc;
|
|
|
|
/*
|
|
* Sanity checks... these are all serious usage bugs.
|
|
*/
|
|
if (!name || in_interrupt() || (size < BYTES_PER_WORD) ||
|
|
(size > (1 << MAX_OBJ_ORDER) * PAGE_SIZE) || (dtor && !ctor)) {
|
|
printk(KERN_ERR "%s: Early error in slab %s\n", __FUNCTION__,
|
|
name);
|
|
BUG();
|
|
}
|
|
|
|
/*
|
|
* We use cache_chain_mutex to ensure a consistent view of
|
|
* cpu_online_map as well. Please see cpuup_callback
|
|
*/
|
|
mutex_lock(&cache_chain_mutex);
|
|
|
|
list_for_each_entry(pc, &cache_chain, next) {
|
|
char tmp;
|
|
int res;
|
|
|
|
/*
|
|
* This happens when the module gets unloaded and doesn't
|
|
* destroy its slab cache and no-one else reuses the vmalloc
|
|
* area of the module. Print a warning.
|
|
*/
|
|
res = probe_kernel_address(pc->name, tmp);
|
|
if (res) {
|
|
printk("SLAB: cache with size %d has lost its name\n",
|
|
pc->buffer_size);
|
|
continue;
|
|
}
|
|
|
|
if (!strcmp(pc->name, name)) {
|
|
printk("kmem_cache_create: duplicate cache %s\n", name);
|
|
dump_stack();
|
|
goto oops;
|
|
}
|
|
}
|
|
|
|
#if DEBUG
|
|
WARN_ON(strchr(name, ' ')); /* It confuses parsers */
|
|
if ((flags & SLAB_DEBUG_INITIAL) && !ctor) {
|
|
/* No constructor, but inital state check requested */
|
|
printk(KERN_ERR "%s: No con, but init state check "
|
|
"requested - %s\n", __FUNCTION__, name);
|
|
flags &= ~SLAB_DEBUG_INITIAL;
|
|
}
|
|
#if FORCED_DEBUG
|
|
/*
|
|
* Enable redzoning and last user accounting, except for caches with
|
|
* large objects, if the increased size would increase the object size
|
|
* above the next power of two: caches with object sizes just above a
|
|
* power of two have a significant amount of internal fragmentation.
|
|
*/
|
|
if (size < 4096 || fls(size - 1) == fls(size-1 + 3 * BYTES_PER_WORD))
|
|
flags |= SLAB_RED_ZONE | SLAB_STORE_USER;
|
|
if (!(flags & SLAB_DESTROY_BY_RCU))
|
|
flags |= SLAB_POISON;
|
|
#endif
|
|
if (flags & SLAB_DESTROY_BY_RCU)
|
|
BUG_ON(flags & SLAB_POISON);
|
|
#endif
|
|
if (flags & SLAB_DESTROY_BY_RCU)
|
|
BUG_ON(dtor);
|
|
|
|
/*
|
|
* Always checks flags, a caller might be expecting debug support which
|
|
* isn't available.
|
|
*/
|
|
BUG_ON(flags & ~CREATE_MASK);
|
|
|
|
/*
|
|
* Check that size is in terms of words. This is needed to avoid
|
|
* unaligned accesses for some archs when redzoning is used, and makes
|
|
* sure any on-slab bufctl's are also correctly aligned.
|
|
*/
|
|
if (size & (BYTES_PER_WORD - 1)) {
|
|
size += (BYTES_PER_WORD - 1);
|
|
size &= ~(BYTES_PER_WORD - 1);
|
|
}
|
|
|
|
/* calculate the final buffer alignment: */
|
|
|
|
/* 1) arch recommendation: can be overridden for debug */
|
|
if (flags & SLAB_HWCACHE_ALIGN) {
|
|
/*
|
|
* Default alignment: as specified by the arch code. Except if
|
|
* an object is really small, then squeeze multiple objects into
|
|
* one cacheline.
|
|
*/
|
|
ralign = cache_line_size();
|
|
while (size <= ralign / 2)
|
|
ralign /= 2;
|
|
} else {
|
|
ralign = BYTES_PER_WORD;
|
|
}
|
|
|
|
/*
|
|
* Redzoning and user store require word alignment. Note this will be
|
|
* overridden by architecture or caller mandated alignment if either
|
|
* is greater than BYTES_PER_WORD.
|
|
*/
|
|
if (flags & SLAB_RED_ZONE || flags & SLAB_STORE_USER)
|
|
ralign = BYTES_PER_WORD;
|
|
|
|
/* 2) arch mandated alignment */
|
|
if (ralign < ARCH_SLAB_MINALIGN) {
|
|
ralign = ARCH_SLAB_MINALIGN;
|
|
}
|
|
/* 3) caller mandated alignment */
|
|
if (ralign < align) {
|
|
ralign = align;
|
|
}
|
|
/* disable debug if necessary */
|
|
if (ralign > BYTES_PER_WORD)
|
|
flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
|
|
/*
|
|
* 4) Store it.
|
|
*/
|
|
align = ralign;
|
|
|
|
/* Get cache's description obj. */
|
|
cachep = kmem_cache_zalloc(&cache_cache, GFP_KERNEL);
|
|
if (!cachep)
|
|
goto oops;
|
|
|
|
#if DEBUG
|
|
cachep->obj_size = size;
|
|
|
|
/*
|
|
* Both debugging options require word-alignment which is calculated
|
|
* into align above.
|
|
*/
|
|
if (flags & SLAB_RED_ZONE) {
|
|
/* add space for red zone words */
|
|
cachep->obj_offset += BYTES_PER_WORD;
|
|
size += 2 * BYTES_PER_WORD;
|
|
}
|
|
if (flags & SLAB_STORE_USER) {
|
|
/* user store requires one word storage behind the end of
|
|
* the real object.
|
|
*/
|
|
size += BYTES_PER_WORD;
|
|
}
|
|
#if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC)
|
|
if (size >= malloc_sizes[INDEX_L3 + 1].cs_size
|
|
&& cachep->obj_size > cache_line_size() && size < PAGE_SIZE) {
|
|
cachep->obj_offset += PAGE_SIZE - size;
|
|
size = PAGE_SIZE;
|
|
}
|
|
#endif
|
|
#endif
|
|
|
|
/*
|
|
* Determine if the slab management is 'on' or 'off' slab.
|
|
* (bootstrapping cannot cope with offslab caches so don't do
|
|
* it too early on.)
|
|
*/
|
|
if ((size >= (PAGE_SIZE >> 3)) && !slab_early_init)
|
|
/*
|
|
* Size is large, assume best to place the slab management obj
|
|
* off-slab (should allow better packing of objs).
|
|
*/
|
|
flags |= CFLGS_OFF_SLAB;
|
|
|
|
size = ALIGN(size, align);
|
|
|
|
left_over = calculate_slab_order(cachep, size, align, flags);
|
|
|
|
if (!cachep->num) {
|
|
printk("kmem_cache_create: couldn't create cache %s.\n", name);
|
|
kmem_cache_free(&cache_cache, cachep);
|
|
cachep = NULL;
|
|
goto oops;
|
|
}
|
|
slab_size = ALIGN(cachep->num * sizeof(kmem_bufctl_t)
|
|
+ sizeof(struct slab), align);
|
|
|
|
/*
|
|
* If the slab has been placed off-slab, and we have enough space then
|
|
* move it on-slab. This is at the expense of any extra colouring.
|
|
*/
|
|
if (flags & CFLGS_OFF_SLAB && left_over >= slab_size) {
|
|
flags &= ~CFLGS_OFF_SLAB;
|
|
left_over -= slab_size;
|
|
}
|
|
|
|
if (flags & CFLGS_OFF_SLAB) {
|
|
/* really off slab. No need for manual alignment */
|
|
slab_size =
|
|
cachep->num * sizeof(kmem_bufctl_t) + sizeof(struct slab);
|
|
}
|
|
|
|
cachep->colour_off = cache_line_size();
|
|
/* Offset must be a multiple of the alignment. */
|
|
if (cachep->colour_off < align)
|
|
cachep->colour_off = align;
|
|
cachep->colour = left_over / cachep->colour_off;
|
|
cachep->slab_size = slab_size;
|
|
cachep->flags = flags;
|
|
cachep->gfpflags = 0;
|
|
if (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA))
|
|
cachep->gfpflags |= GFP_DMA;
|
|
cachep->buffer_size = size;
|
|
cachep->reciprocal_buffer_size = reciprocal_value(size);
|
|
|
|
if (flags & CFLGS_OFF_SLAB) {
|
|
cachep->slabp_cache = kmem_find_general_cachep(slab_size, 0u);
|
|
/*
|
|
* This is a possibility for one of the malloc_sizes caches.
|
|
* But since we go off slab only for object size greater than
|
|
* PAGE_SIZE/8, and malloc_sizes gets created in ascending order,
|
|
* this should not happen at all.
|
|
* But leave a BUG_ON for some lucky dude.
|
|
*/
|
|
BUG_ON(!cachep->slabp_cache);
|
|
}
|
|
cachep->ctor = ctor;
|
|
cachep->dtor = dtor;
|
|
cachep->name = name;
|
|
|
|
if (setup_cpu_cache(cachep)) {
|
|
__kmem_cache_destroy(cachep);
|
|
cachep = NULL;
|
|
goto oops;
|
|
}
|
|
|
|
/* cache setup completed, link it into the list */
|
|
list_add(&cachep->next, &cache_chain);
|
|
oops:
|
|
if (!cachep && (flags & SLAB_PANIC))
|
|
panic("kmem_cache_create(): failed to create slab `%s'\n",
|
|
name);
|
|
mutex_unlock(&cache_chain_mutex);
|
|
return cachep;
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_create);
|
|
|
|
#if DEBUG
|
|
static void check_irq_off(void)
|
|
{
|
|
BUG_ON(!irqs_disabled());
|
|
}
|
|
|
|
static void check_irq_on(void)
|
|
{
|
|
BUG_ON(irqs_disabled());
|
|
}
|
|
|
|
static void check_spinlock_acquired(struct kmem_cache *cachep)
|
|
{
|
|
#ifdef CONFIG_SMP
|
|
check_irq_off();
|
|
assert_spin_locked(&cachep->nodelists[numa_node_id()]->list_lock);
|
|
#endif
|
|
}
|
|
|
|
static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node)
|
|
{
|
|
#ifdef CONFIG_SMP
|
|
check_irq_off();
|
|
assert_spin_locked(&cachep->nodelists[node]->list_lock);
|
|
#endif
|
|
}
|
|
|
|
#else
|
|
#define check_irq_off() do { } while(0)
|
|
#define check_irq_on() do { } while(0)
|
|
#define check_spinlock_acquired(x) do { } while(0)
|
|
#define check_spinlock_acquired_node(x, y) do { } while(0)
|
|
#endif
|
|
|
|
static void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3,
|
|
struct array_cache *ac,
|
|
int force, int node);
|
|
|
|
static void do_drain(void *arg)
|
|
{
|
|
struct kmem_cache *cachep = arg;
|
|
struct array_cache *ac;
|
|
int node = numa_node_id();
|
|
|
|
check_irq_off();
|
|
ac = cpu_cache_get(cachep);
|
|
spin_lock(&cachep->nodelists[node]->list_lock);
|
|
free_block(cachep, ac->entry, ac->avail, node);
|
|
spin_unlock(&cachep->nodelists[node]->list_lock);
|
|
ac->avail = 0;
|
|
}
|
|
|
|
static void drain_cpu_caches(struct kmem_cache *cachep)
|
|
{
|
|
struct kmem_list3 *l3;
|
|
int node;
|
|
|
|
on_each_cpu(do_drain, cachep, 1, 1);
|
|
check_irq_on();
|
|
for_each_online_node(node) {
|
|
l3 = cachep->nodelists[node];
|
|
if (l3 && l3->alien)
|
|
drain_alien_cache(cachep, l3->alien);
|
|
}
|
|
|
|
for_each_online_node(node) {
|
|
l3 = cachep->nodelists[node];
|
|
if (l3)
|
|
drain_array(cachep, l3, l3->shared, 1, node);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Remove slabs from the list of free slabs.
|
|
* Specify the number of slabs to drain in tofree.
|
|
*
|
|
* Returns the actual number of slabs released.
|
|
*/
|
|
static int drain_freelist(struct kmem_cache *cache,
|
|
struct kmem_list3 *l3, int tofree)
|
|
{
|
|
struct list_head *p;
|
|
int nr_freed;
|
|
struct slab *slabp;
|
|
|
|
nr_freed = 0;
|
|
while (nr_freed < tofree && !list_empty(&l3->slabs_free)) {
|
|
|
|
spin_lock_irq(&l3->list_lock);
|
|
p = l3->slabs_free.prev;
|
|
if (p == &l3->slabs_free) {
|
|
spin_unlock_irq(&l3->list_lock);
|
|
goto out;
|
|
}
|
|
|
|
slabp = list_entry(p, struct slab, list);
|
|
#if DEBUG
|
|
BUG_ON(slabp->inuse);
|
|
#endif
|
|
list_del(&slabp->list);
|
|
/*
|
|
* Safe to drop the lock. The slab is no longer linked
|
|
* to the cache.
|
|
*/
|
|
l3->free_objects -= cache->num;
|
|
spin_unlock_irq(&l3->list_lock);
|
|
slab_destroy(cache, slabp);
|
|
nr_freed++;
|
|
}
|
|
out:
|
|
return nr_freed;
|
|
}
|
|
|
|
/* Called with cache_chain_mutex held to protect against cpu hotplug */
|
|
static int __cache_shrink(struct kmem_cache *cachep)
|
|
{
|
|
int ret = 0, i = 0;
|
|
struct kmem_list3 *l3;
|
|
|
|
drain_cpu_caches(cachep);
|
|
|
|
check_irq_on();
|
|
for_each_online_node(i) {
|
|
l3 = cachep->nodelists[i];
|
|
if (!l3)
|
|
continue;
|
|
|
|
drain_freelist(cachep, l3, l3->free_objects);
|
|
|
|
ret += !list_empty(&l3->slabs_full) ||
|
|
!list_empty(&l3->slabs_partial);
|
|
}
|
|
return (ret ? 1 : 0);
|
|
}
|
|
|
|
/**
|
|
* kmem_cache_shrink - Shrink a cache.
|
|
* @cachep: The cache to shrink.
|
|
*
|
|
* Releases as many slabs as possible for a cache.
|
|
* To help debugging, a zero exit status indicates all slabs were released.
|
|
*/
|
|
int kmem_cache_shrink(struct kmem_cache *cachep)
|
|
{
|
|
int ret;
|
|
BUG_ON(!cachep || in_interrupt());
|
|
|
|
mutex_lock(&cache_chain_mutex);
|
|
ret = __cache_shrink(cachep);
|
|
mutex_unlock(&cache_chain_mutex);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_shrink);
|
|
|
|
/**
|
|
* kmem_cache_destroy - delete a cache
|
|
* @cachep: the cache to destroy
|
|
*
|
|
* Remove a &struct kmem_cache object from the slab cache.
|
|
*
|
|
* It is expected this function will be called by a module when it is
|
|
* unloaded. This will remove the cache completely, and avoid a duplicate
|
|
* cache being allocated each time a module is loaded and unloaded, if the
|
|
* module doesn't have persistent in-kernel storage across loads and unloads.
|
|
*
|
|
* The cache must be empty before calling this function.
|
|
*
|
|
* The caller must guarantee that noone will allocate memory from the cache
|
|
* during the kmem_cache_destroy().
|
|
*/
|
|
void kmem_cache_destroy(struct kmem_cache *cachep)
|
|
{
|
|
BUG_ON(!cachep || in_interrupt());
|
|
|
|
/* Find the cache in the chain of caches. */
|
|
mutex_lock(&cache_chain_mutex);
|
|
/*
|
|
* the chain is never empty, cache_cache is never destroyed
|
|
*/
|
|
list_del(&cachep->next);
|
|
if (__cache_shrink(cachep)) {
|
|
slab_error(cachep, "Can't free all objects");
|
|
list_add(&cachep->next, &cache_chain);
|
|
mutex_unlock(&cache_chain_mutex);
|
|
return;
|
|
}
|
|
|
|
if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU))
|
|
synchronize_rcu();
|
|
|
|
__kmem_cache_destroy(cachep);
|
|
mutex_unlock(&cache_chain_mutex);
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_destroy);
|
|
|
|
/*
|
|
* Get the memory for a slab management obj.
|
|
* For a slab cache when the slab descriptor is off-slab, slab descriptors
|
|
* always come from malloc_sizes caches. The slab descriptor cannot
|
|
* come from the same cache which is getting created because,
|
|
* when we are searching for an appropriate cache for these
|
|
* descriptors in kmem_cache_create, we search through the malloc_sizes array.
|
|
* If we are creating a malloc_sizes cache here it would not be visible to
|
|
* kmem_find_general_cachep till the initialization is complete.
|
|
* Hence we cannot have slabp_cache same as the original cache.
|
|
*/
|
|
static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp,
|
|
int colour_off, gfp_t local_flags,
|
|
int nodeid)
|
|
{
|
|
struct slab *slabp;
|
|
|
|
if (OFF_SLAB(cachep)) {
|
|
/* Slab management obj is off-slab. */
|
|
slabp = kmem_cache_alloc_node(cachep->slabp_cache,
|
|
local_flags & ~GFP_THISNODE, nodeid);
|
|
if (!slabp)
|
|
return NULL;
|
|
} else {
|
|
slabp = objp + colour_off;
|
|
colour_off += cachep->slab_size;
|
|
}
|
|
slabp->inuse = 0;
|
|
slabp->colouroff = colour_off;
|
|
slabp->s_mem = objp + colour_off;
|
|
slabp->nodeid = nodeid;
|
|
return slabp;
|
|
}
|
|
|
|
static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp)
|
|
{
|
|
return (kmem_bufctl_t *) (slabp + 1);
|
|
}
|
|
|
|
static void cache_init_objs(struct kmem_cache *cachep,
|
|
struct slab *slabp, unsigned long ctor_flags)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < cachep->num; i++) {
|
|
void *objp = index_to_obj(cachep, slabp, i);
|
|
#if DEBUG
|
|
/* need to poison the objs? */
|
|
if (cachep->flags & SLAB_POISON)
|
|
poison_obj(cachep, objp, POISON_FREE);
|
|
if (cachep->flags & SLAB_STORE_USER)
|
|
*dbg_userword(cachep, objp) = NULL;
|
|
|
|
if (cachep->flags & SLAB_RED_ZONE) {
|
|
*dbg_redzone1(cachep, objp) = RED_INACTIVE;
|
|
*dbg_redzone2(cachep, objp) = RED_INACTIVE;
|
|
}
|
|
/*
|
|
* Constructors are not allowed to allocate memory from the same
|
|
* cache which they are a constructor for. Otherwise, deadlock.
|
|
* They must also be threaded.
|
|
*/
|
|
if (cachep->ctor && !(cachep->flags & SLAB_POISON))
|
|
cachep->ctor(objp + obj_offset(cachep), cachep,
|
|
ctor_flags);
|
|
|
|
if (cachep->flags & SLAB_RED_ZONE) {
|
|
if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
|
|
slab_error(cachep, "constructor overwrote the"
|
|
" end of an object");
|
|
if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
|
|
slab_error(cachep, "constructor overwrote the"
|
|
" start of an object");
|
|
}
|
|
if ((cachep->buffer_size % PAGE_SIZE) == 0 &&
|
|
OFF_SLAB(cachep) && cachep->flags & SLAB_POISON)
|
|
kernel_map_pages(virt_to_page(objp),
|
|
cachep->buffer_size / PAGE_SIZE, 0);
|
|
#else
|
|
if (cachep->ctor)
|
|
cachep->ctor(objp, cachep, ctor_flags);
|
|
#endif
|
|
slab_bufctl(slabp)[i] = i + 1;
|
|
}
|
|
slab_bufctl(slabp)[i - 1] = BUFCTL_END;
|
|
slabp->free = 0;
|
|
}
|
|
|
|
static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags)
|
|
{
|
|
if (CONFIG_ZONE_DMA_FLAG) {
|
|
if (flags & GFP_DMA)
|
|
BUG_ON(!(cachep->gfpflags & GFP_DMA));
|
|
else
|
|
BUG_ON(cachep->gfpflags & GFP_DMA);
|
|
}
|
|
}
|
|
|
|
static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp,
|
|
int nodeid)
|
|
{
|
|
void *objp = index_to_obj(cachep, slabp, slabp->free);
|
|
kmem_bufctl_t next;
|
|
|
|
slabp->inuse++;
|
|
next = slab_bufctl(slabp)[slabp->free];
|
|
#if DEBUG
|
|
slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE;
|
|
WARN_ON(slabp->nodeid != nodeid);
|
|
#endif
|
|
slabp->free = next;
|
|
|
|
return objp;
|
|
}
|
|
|
|
static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
|
|
void *objp, int nodeid)
|
|
{
|
|
unsigned int objnr = obj_to_index(cachep, slabp, objp);
|
|
|
|
#if DEBUG
|
|
/* Verify that the slab belongs to the intended node */
|
|
WARN_ON(slabp->nodeid != nodeid);
|
|
|
|
if (slab_bufctl(slabp)[objnr] + 1 <= SLAB_LIMIT + 1) {
|
|
printk(KERN_ERR "slab: double free detected in cache "
|
|
"'%s', objp %p\n", cachep->name, objp);
|
|
BUG();
|
|
}
|
|
#endif
|
|
slab_bufctl(slabp)[objnr] = slabp->free;
|
|
slabp->free = objnr;
|
|
slabp->inuse--;
|
|
}
|
|
|
|
/*
|
|
* Map pages beginning at addr to the given cache and slab. This is required
|
|
* for the slab allocator to be able to lookup the cache and slab of a
|
|
* virtual address for kfree, ksize, kmem_ptr_validate, and slab debugging.
|
|
*/
|
|
static void slab_map_pages(struct kmem_cache *cache, struct slab *slab,
|
|
void *addr)
|
|
{
|
|
int nr_pages;
|
|
struct page *page;
|
|
|
|
page = virt_to_page(addr);
|
|
|
|
nr_pages = 1;
|
|
if (likely(!PageCompound(page)))
|
|
nr_pages <<= cache->gfporder;
|
|
|
|
do {
|
|
page_set_cache(page, cache);
|
|
page_set_slab(page, slab);
|
|
page++;
|
|
} while (--nr_pages);
|
|
}
|
|
|
|
/*
|
|
* Grow (by 1) the number of slabs within a cache. This is called by
|
|
* kmem_cache_alloc() when there are no active objs left in a cache.
|
|
*/
|
|
static int cache_grow(struct kmem_cache *cachep,
|
|
gfp_t flags, int nodeid, void *objp)
|
|
{
|
|
struct slab *slabp;
|
|
size_t offset;
|
|
gfp_t local_flags;
|
|
unsigned long ctor_flags;
|
|
struct kmem_list3 *l3;
|
|
|
|
/*
|
|
* Be lazy and only check for valid flags here, keeping it out of the
|
|
* critical path in kmem_cache_alloc().
|
|
*/
|
|
BUG_ON(flags & ~(GFP_DMA | GFP_LEVEL_MASK | __GFP_NO_GROW));
|
|
if (flags & __GFP_NO_GROW)
|
|
return 0;
|
|
|
|
ctor_flags = SLAB_CTOR_CONSTRUCTOR;
|
|
local_flags = (flags & GFP_LEVEL_MASK);
|
|
if (!(local_flags & __GFP_WAIT))
|
|
/*
|
|
* Not allowed to sleep. Need to tell a constructor about
|
|
* this - it might need to know...
|
|
*/
|
|
ctor_flags |= SLAB_CTOR_ATOMIC;
|
|
|
|
/* Take the l3 list lock to change the colour_next on this node */
|
|
check_irq_off();
|
|
l3 = cachep->nodelists[nodeid];
|
|
spin_lock(&l3->list_lock);
|
|
|
|
/* Get colour for the slab, and cal the next value. */
|
|
offset = l3->colour_next;
|
|
l3->colour_next++;
|
|
if (l3->colour_next >= cachep->colour)
|
|
l3->colour_next = 0;
|
|
spin_unlock(&l3->list_lock);
|
|
|
|
offset *= cachep->colour_off;
|
|
|
|
if (local_flags & __GFP_WAIT)
|
|
local_irq_enable();
|
|
|
|
/*
|
|
* The test for missing atomic flag is performed here, rather than
|
|
* the more obvious place, simply to reduce the critical path length
|
|
* in kmem_cache_alloc(). If a caller is seriously mis-behaving they
|
|
* will eventually be caught here (where it matters).
|
|
*/
|
|
kmem_flagcheck(cachep, flags);
|
|
|
|
/*
|
|
* Get mem for the objs. Attempt to allocate a physical page from
|
|
* 'nodeid'.
|
|
*/
|
|
if (!objp)
|
|
objp = kmem_getpages(cachep, flags, nodeid);
|
|
if (!objp)
|
|
goto failed;
|
|
|
|
/* Get slab management. */
|
|
slabp = alloc_slabmgmt(cachep, objp, offset,
|
|
local_flags & ~GFP_THISNODE, nodeid);
|
|
if (!slabp)
|
|
goto opps1;
|
|
|
|
slabp->nodeid = nodeid;
|
|
slab_map_pages(cachep, slabp, objp);
|
|
|
|
cache_init_objs(cachep, slabp, ctor_flags);
|
|
|
|
if (local_flags & __GFP_WAIT)
|
|
local_irq_disable();
|
|
check_irq_off();
|
|
spin_lock(&l3->list_lock);
|
|
|
|
/* Make slab active. */
|
|
list_add_tail(&slabp->list, &(l3->slabs_free));
|
|
STATS_INC_GROWN(cachep);
|
|
l3->free_objects += cachep->num;
|
|
spin_unlock(&l3->list_lock);
|
|
return 1;
|
|
opps1:
|
|
kmem_freepages(cachep, objp);
|
|
failed:
|
|
if (local_flags & __GFP_WAIT)
|
|
local_irq_disable();
|
|
return 0;
|
|
}
|
|
|
|
#if DEBUG
|
|
|
|
/*
|
|
* Perform extra freeing checks:
|
|
* - detect bad pointers.
|
|
* - POISON/RED_ZONE checking
|
|
* - destructor calls, for caches with POISON+dtor
|
|
*/
|
|
static void kfree_debugcheck(const void *objp)
|
|
{
|
|
if (!virt_addr_valid(objp)) {
|
|
printk(KERN_ERR "kfree_debugcheck: out of range ptr %lxh.\n",
|
|
(unsigned long)objp);
|
|
BUG();
|
|
}
|
|
}
|
|
|
|
static inline void verify_redzone_free(struct kmem_cache *cache, void *obj)
|
|
{
|
|
unsigned long redzone1, redzone2;
|
|
|
|
redzone1 = *dbg_redzone1(cache, obj);
|
|
redzone2 = *dbg_redzone2(cache, obj);
|
|
|
|
/*
|
|
* Redzone is ok.
|
|
*/
|
|
if (redzone1 == RED_ACTIVE && redzone2 == RED_ACTIVE)
|
|
return;
|
|
|
|
if (redzone1 == RED_INACTIVE && redzone2 == RED_INACTIVE)
|
|
slab_error(cache, "double free detected");
|
|
else
|
|
slab_error(cache, "memory outside object was overwritten");
|
|
|
|
printk(KERN_ERR "%p: redzone 1:0x%lx, redzone 2:0x%lx.\n",
|
|
obj, redzone1, redzone2);
|
|
}
|
|
|
|
static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
|
|
void *caller)
|
|
{
|
|
struct page *page;
|
|
unsigned int objnr;
|
|
struct slab *slabp;
|
|
|
|
objp -= obj_offset(cachep);
|
|
kfree_debugcheck(objp);
|
|
page = virt_to_page(objp);
|
|
|
|
slabp = page_get_slab(page);
|
|
|
|
if (cachep->flags & SLAB_RED_ZONE) {
|
|
verify_redzone_free(cachep, objp);
|
|
*dbg_redzone1(cachep, objp) = RED_INACTIVE;
|
|
*dbg_redzone2(cachep, objp) = RED_INACTIVE;
|
|
}
|
|
if (cachep->flags & SLAB_STORE_USER)
|
|
*dbg_userword(cachep, objp) = caller;
|
|
|
|
objnr = obj_to_index(cachep, slabp, objp);
|
|
|
|
BUG_ON(objnr >= cachep->num);
|
|
BUG_ON(objp != index_to_obj(cachep, slabp, objnr));
|
|
|
|
if (cachep->flags & SLAB_DEBUG_INITIAL) {
|
|
/*
|
|
* Need to call the slab's constructor so the caller can
|
|
* perform a verify of its state (debugging). Called without
|
|
* the cache-lock held.
|
|
*/
|
|
cachep->ctor(objp + obj_offset(cachep),
|
|
cachep, SLAB_CTOR_CONSTRUCTOR | SLAB_CTOR_VERIFY);
|
|
}
|
|
if (cachep->flags & SLAB_POISON && cachep->dtor) {
|
|
/* we want to cache poison the object,
|
|
* call the destruction callback
|
|
*/
|
|
cachep->dtor(objp + obj_offset(cachep), cachep, 0);
|
|
}
|
|
#ifdef CONFIG_DEBUG_SLAB_LEAK
|
|
slab_bufctl(slabp)[objnr] = BUFCTL_FREE;
|
|
#endif
|
|
if (cachep->flags & SLAB_POISON) {
|
|
#ifdef CONFIG_DEBUG_PAGEALLOC
|
|
if ((cachep->buffer_size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) {
|
|
store_stackinfo(cachep, objp, (unsigned long)caller);
|
|
kernel_map_pages(virt_to_page(objp),
|
|
cachep->buffer_size / PAGE_SIZE, 0);
|
|
} else {
|
|
poison_obj(cachep, objp, POISON_FREE);
|
|
}
|
|
#else
|
|
poison_obj(cachep, objp, POISON_FREE);
|
|
#endif
|
|
}
|
|
return objp;
|
|
}
|
|
|
|
static void check_slabp(struct kmem_cache *cachep, struct slab *slabp)
|
|
{
|
|
kmem_bufctl_t i;
|
|
int entries = 0;
|
|
|
|
/* Check slab's freelist to see if this obj is there. */
|
|
for (i = slabp->free; i != BUFCTL_END; i = slab_bufctl(slabp)[i]) {
|
|
entries++;
|
|
if (entries > cachep->num || i >= cachep->num)
|
|
goto bad;
|
|
}
|
|
if (entries != cachep->num - slabp->inuse) {
|
|
bad:
|
|
printk(KERN_ERR "slab: Internal list corruption detected in "
|
|
"cache '%s'(%d), slabp %p(%d). Hexdump:\n",
|
|
cachep->name, cachep->num, slabp, slabp->inuse);
|
|
for (i = 0;
|
|
i < sizeof(*slabp) + cachep->num * sizeof(kmem_bufctl_t);
|
|
i++) {
|
|
if (i % 16 == 0)
|
|
printk("\n%03x:", i);
|
|
printk(" %02x", ((unsigned char *)slabp)[i]);
|
|
}
|
|
printk("\n");
|
|
BUG();
|
|
}
|
|
}
|
|
#else
|
|
#define kfree_debugcheck(x) do { } while(0)
|
|
#define cache_free_debugcheck(x,objp,z) (objp)
|
|
#define check_slabp(x,y) do { } while(0)
|
|
#endif
|
|
|
|
static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags)
|
|
{
|
|
int batchcount;
|
|
struct kmem_list3 *l3;
|
|
struct array_cache *ac;
|
|
int node;
|
|
|
|
node = numa_node_id();
|
|
|
|
check_irq_off();
|
|
ac = cpu_cache_get(cachep);
|
|
retry:
|
|
batchcount = ac->batchcount;
|
|
if (!ac->touched && batchcount > BATCHREFILL_LIMIT) {
|
|
/*
|
|
* If there was little recent activity on this cache, then
|
|
* perform only a partial refill. Otherwise we could generate
|
|
* refill bouncing.
|
|
*/
|
|
batchcount = BATCHREFILL_LIMIT;
|
|
}
|
|
l3 = cachep->nodelists[node];
|
|
|
|
BUG_ON(ac->avail > 0 || !l3);
|
|
spin_lock(&l3->list_lock);
|
|
|
|
/* See if we can refill from the shared array */
|
|
if (l3->shared && transfer_objects(ac, l3->shared, batchcount))
|
|
goto alloc_done;
|
|
|
|
while (batchcount > 0) {
|
|
struct list_head *entry;
|
|
struct slab *slabp;
|
|
/* Get slab alloc is to come from. */
|
|
entry = l3->slabs_partial.next;
|
|
if (entry == &l3->slabs_partial) {
|
|
l3->free_touched = 1;
|
|
entry = l3->slabs_free.next;
|
|
if (entry == &l3->slabs_free)
|
|
goto must_grow;
|
|
}
|
|
|
|
slabp = list_entry(entry, struct slab, list);
|
|
check_slabp(cachep, slabp);
|
|
check_spinlock_acquired(cachep);
|
|
while (slabp->inuse < cachep->num && batchcount--) {
|
|
STATS_INC_ALLOCED(cachep);
|
|
STATS_INC_ACTIVE(cachep);
|
|
STATS_SET_HIGH(cachep);
|
|
|
|
ac->entry[ac->avail++] = slab_get_obj(cachep, slabp,
|
|
node);
|
|
}
|
|
check_slabp(cachep, slabp);
|
|
|
|
/* move slabp to correct slabp list: */
|
|
list_del(&slabp->list);
|
|
if (slabp->free == BUFCTL_END)
|
|
list_add(&slabp->list, &l3->slabs_full);
|
|
else
|
|
list_add(&slabp->list, &l3->slabs_partial);
|
|
}
|
|
|
|
must_grow:
|
|
l3->free_objects -= ac->avail;
|
|
alloc_done:
|
|
spin_unlock(&l3->list_lock);
|
|
|
|
if (unlikely(!ac->avail)) {
|
|
int x;
|
|
x = cache_grow(cachep, flags | GFP_THISNODE, node, NULL);
|
|
|
|
/* cache_grow can reenable interrupts, then ac could change. */
|
|
ac = cpu_cache_get(cachep);
|
|
if (!x && ac->avail == 0) /* no objects in sight? abort */
|
|
return NULL;
|
|
|
|
if (!ac->avail) /* objects refilled by interrupt? */
|
|
goto retry;
|
|
}
|
|
ac->touched = 1;
|
|
return ac->entry[--ac->avail];
|
|
}
|
|
|
|
static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep,
|
|
gfp_t flags)
|
|
{
|
|
might_sleep_if(flags & __GFP_WAIT);
|
|
#if DEBUG
|
|
kmem_flagcheck(cachep, flags);
|
|
#endif
|
|
}
|
|
|
|
#if DEBUG
|
|
static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
|
|
gfp_t flags, void *objp, void *caller)
|
|
{
|
|
if (!objp)
|
|
return objp;
|
|
if (cachep->flags & SLAB_POISON) {
|
|
#ifdef CONFIG_DEBUG_PAGEALLOC
|
|
if ((cachep->buffer_size % PAGE_SIZE) == 0 && OFF_SLAB(cachep))
|
|
kernel_map_pages(virt_to_page(objp),
|
|
cachep->buffer_size / PAGE_SIZE, 1);
|
|
else
|
|
check_poison_obj(cachep, objp);
|
|
#else
|
|
check_poison_obj(cachep, objp);
|
|
#endif
|
|
poison_obj(cachep, objp, POISON_INUSE);
|
|
}
|
|
if (cachep->flags & SLAB_STORE_USER)
|
|
*dbg_userword(cachep, objp) = caller;
|
|
|
|
if (cachep->flags & SLAB_RED_ZONE) {
|
|
if (*dbg_redzone1(cachep, objp) != RED_INACTIVE ||
|
|
*dbg_redzone2(cachep, objp) != RED_INACTIVE) {
|
|
slab_error(cachep, "double free, or memory outside"
|
|
" object was overwritten");
|
|
printk(KERN_ERR
|
|
"%p: redzone 1:0x%lx, redzone 2:0x%lx\n",
|
|
objp, *dbg_redzone1(cachep, objp),
|
|
*dbg_redzone2(cachep, objp));
|
|
}
|
|
*dbg_redzone1(cachep, objp) = RED_ACTIVE;
|
|
*dbg_redzone2(cachep, objp) = RED_ACTIVE;
|
|
}
|
|
#ifdef CONFIG_DEBUG_SLAB_LEAK
|
|
{
|
|
struct slab *slabp;
|
|
unsigned objnr;
|
|
|
|
slabp = page_get_slab(virt_to_page(objp));
|
|
objnr = (unsigned)(objp - slabp->s_mem) / cachep->buffer_size;
|
|
slab_bufctl(slabp)[objnr] = BUFCTL_ACTIVE;
|
|
}
|
|
#endif
|
|
objp += obj_offset(cachep);
|
|
if (cachep->ctor && cachep->flags & SLAB_POISON) {
|
|
unsigned long ctor_flags = SLAB_CTOR_CONSTRUCTOR;
|
|
|
|
if (!(flags & __GFP_WAIT))
|
|
ctor_flags |= SLAB_CTOR_ATOMIC;
|
|
|
|
cachep->ctor(objp, cachep, ctor_flags);
|
|
}
|
|
#if ARCH_SLAB_MINALIGN
|
|
if ((u32)objp & (ARCH_SLAB_MINALIGN-1)) {
|
|
printk(KERN_ERR "0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n",
|
|
objp, ARCH_SLAB_MINALIGN);
|
|
}
|
|
#endif
|
|
return objp;
|
|
}
|
|
#else
|
|
#define cache_alloc_debugcheck_after(a,b,objp,d) (objp)
|
|
#endif
|
|
|
|
#ifdef CONFIG_FAILSLAB
|
|
|
|
static struct failslab_attr {
|
|
|
|
struct fault_attr attr;
|
|
|
|
u32 ignore_gfp_wait;
|
|
#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
|
|
struct dentry *ignore_gfp_wait_file;
|
|
#endif
|
|
|
|
} failslab = {
|
|
.attr = FAULT_ATTR_INITIALIZER,
|
|
.ignore_gfp_wait = 1,
|
|
};
|
|
|
|
static int __init setup_failslab(char *str)
|
|
{
|
|
return setup_fault_attr(&failslab.attr, str);
|
|
}
|
|
__setup("failslab=", setup_failslab);
|
|
|
|
static int should_failslab(struct kmem_cache *cachep, gfp_t flags)
|
|
{
|
|
if (cachep == &cache_cache)
|
|
return 0;
|
|
if (flags & __GFP_NOFAIL)
|
|
return 0;
|
|
if (failslab.ignore_gfp_wait && (flags & __GFP_WAIT))
|
|
return 0;
|
|
|
|
return should_fail(&failslab.attr, obj_size(cachep));
|
|
}
|
|
|
|
#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
|
|
|
|
static int __init failslab_debugfs(void)
|
|
{
|
|
mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
|
|
struct dentry *dir;
|
|
int err;
|
|
|
|
err = init_fault_attr_dentries(&failslab.attr, "failslab");
|
|
if (err)
|
|
return err;
|
|
dir = failslab.attr.dentries.dir;
|
|
|
|
failslab.ignore_gfp_wait_file =
|
|
debugfs_create_bool("ignore-gfp-wait", mode, dir,
|
|
&failslab.ignore_gfp_wait);
|
|
|
|
if (!failslab.ignore_gfp_wait_file) {
|
|
err = -ENOMEM;
|
|
debugfs_remove(failslab.ignore_gfp_wait_file);
|
|
cleanup_fault_attr_dentries(&failslab.attr);
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
late_initcall(failslab_debugfs);
|
|
|
|
#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
|
|
|
|
#else /* CONFIG_FAILSLAB */
|
|
|
|
static inline int should_failslab(struct kmem_cache *cachep, gfp_t flags)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
#endif /* CONFIG_FAILSLAB */
|
|
|
|
static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags)
|
|
{
|
|
void *objp;
|
|
struct array_cache *ac;
|
|
|
|
check_irq_off();
|
|
|
|
if (should_failslab(cachep, flags))
|
|
return NULL;
|
|
|
|
ac = cpu_cache_get(cachep);
|
|
if (likely(ac->avail)) {
|
|
STATS_INC_ALLOCHIT(cachep);
|
|
ac->touched = 1;
|
|
objp = ac->entry[--ac->avail];
|
|
} else {
|
|
STATS_INC_ALLOCMISS(cachep);
|
|
objp = cache_alloc_refill(cachep, flags);
|
|
}
|
|
return objp;
|
|
}
|
|
|
|
#ifdef CONFIG_NUMA
|
|
/*
|
|
* Try allocating on another node if PF_SPREAD_SLAB|PF_MEMPOLICY.
|
|
*
|
|
* If we are in_interrupt, then process context, including cpusets and
|
|
* mempolicy, may not apply and should not be used for allocation policy.
|
|
*/
|
|
static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags)
|
|
{
|
|
int nid_alloc, nid_here;
|
|
|
|
if (in_interrupt() || (flags & __GFP_THISNODE))
|
|
return NULL;
|
|
nid_alloc = nid_here = numa_node_id();
|
|
if (cpuset_do_slab_mem_spread() && (cachep->flags & SLAB_MEM_SPREAD))
|
|
nid_alloc = cpuset_mem_spread_node();
|
|
else if (current->mempolicy)
|
|
nid_alloc = slab_node(current->mempolicy);
|
|
if (nid_alloc != nid_here)
|
|
return ____cache_alloc_node(cachep, flags, nid_alloc);
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Fallback function if there was no memory available and no objects on a
|
|
* certain node and fall back is permitted. First we scan all the
|
|
* available nodelists for available objects. If that fails then we
|
|
* perform an allocation without specifying a node. This allows the page
|
|
* allocator to do its reclaim / fallback magic. We then insert the
|
|
* slab into the proper nodelist and then allocate from it.
|
|
*/
|
|
static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags)
|
|
{
|
|
struct zonelist *zonelist;
|
|
gfp_t local_flags;
|
|
struct zone **z;
|
|
void *obj = NULL;
|
|
int nid;
|
|
|
|
if (flags & __GFP_THISNODE)
|
|
return NULL;
|
|
|
|
zonelist = &NODE_DATA(slab_node(current->mempolicy))
|
|
->node_zonelists[gfp_zone(flags)];
|
|
local_flags = (flags & GFP_LEVEL_MASK);
|
|
|
|
retry:
|
|
/*
|
|
* Look through allowed nodes for objects available
|
|
* from existing per node queues.
|
|
*/
|
|
for (z = zonelist->zones; *z && !obj; z++) {
|
|
nid = zone_to_nid(*z);
|
|
|
|
if (cpuset_zone_allowed_hardwall(*z, flags) &&
|
|
cache->nodelists[nid] &&
|
|
cache->nodelists[nid]->free_objects)
|
|
obj = ____cache_alloc_node(cache,
|
|
flags | GFP_THISNODE, nid);
|
|
}
|
|
|
|
if (!obj && !(flags & __GFP_NO_GROW)) {
|
|
/*
|
|
* This allocation will be performed within the constraints
|
|
* of the current cpuset / memory policy requirements.
|
|
* We may trigger various forms of reclaim on the allowed
|
|
* set and go into memory reserves if necessary.
|
|
*/
|
|
if (local_flags & __GFP_WAIT)
|
|
local_irq_enable();
|
|
kmem_flagcheck(cache, flags);
|
|
obj = kmem_getpages(cache, flags, -1);
|
|
if (local_flags & __GFP_WAIT)
|
|
local_irq_disable();
|
|
if (obj) {
|
|
/*
|
|
* Insert into the appropriate per node queues
|
|
*/
|
|
nid = page_to_nid(virt_to_page(obj));
|
|
if (cache_grow(cache, flags, nid, obj)) {
|
|
obj = ____cache_alloc_node(cache,
|
|
flags | GFP_THISNODE, nid);
|
|
if (!obj)
|
|
/*
|
|
* Another processor may allocate the
|
|
* objects in the slab since we are
|
|
* not holding any locks.
|
|
*/
|
|
goto retry;
|
|
} else {
|
|
/* cache_grow already freed obj */
|
|
obj = NULL;
|
|
}
|
|
}
|
|
}
|
|
return obj;
|
|
}
|
|
|
|
/*
|
|
* A interface to enable slab creation on nodeid
|
|
*/
|
|
static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
|
|
int nodeid)
|
|
{
|
|
struct list_head *entry;
|
|
struct slab *slabp;
|
|
struct kmem_list3 *l3;
|
|
void *obj;
|
|
int x;
|
|
|
|
l3 = cachep->nodelists[nodeid];
|
|
BUG_ON(!l3);
|
|
|
|
retry:
|
|
check_irq_off();
|
|
spin_lock(&l3->list_lock);
|
|
entry = l3->slabs_partial.next;
|
|
if (entry == &l3->slabs_partial) {
|
|
l3->free_touched = 1;
|
|
entry = l3->slabs_free.next;
|
|
if (entry == &l3->slabs_free)
|
|
goto must_grow;
|
|
}
|
|
|
|
slabp = list_entry(entry, struct slab, list);
|
|
check_spinlock_acquired_node(cachep, nodeid);
|
|
check_slabp(cachep, slabp);
|
|
|
|
STATS_INC_NODEALLOCS(cachep);
|
|
STATS_INC_ACTIVE(cachep);
|
|
STATS_SET_HIGH(cachep);
|
|
|
|
BUG_ON(slabp->inuse == cachep->num);
|
|
|
|
obj = slab_get_obj(cachep, slabp, nodeid);
|
|
check_slabp(cachep, slabp);
|
|
l3->free_objects--;
|
|
/* move slabp to correct slabp list: */
|
|
list_del(&slabp->list);
|
|
|
|
if (slabp->free == BUFCTL_END)
|
|
list_add(&slabp->list, &l3->slabs_full);
|
|
else
|
|
list_add(&slabp->list, &l3->slabs_partial);
|
|
|
|
spin_unlock(&l3->list_lock);
|
|
goto done;
|
|
|
|
must_grow:
|
|
spin_unlock(&l3->list_lock);
|
|
x = cache_grow(cachep, flags | GFP_THISNODE, nodeid, NULL);
|
|
if (x)
|
|
goto retry;
|
|
|
|
return fallback_alloc(cachep, flags);
|
|
|
|
done:
|
|
return obj;
|
|
}
|
|
|
|
/**
|
|
* kmem_cache_alloc_node - Allocate an object on the specified node
|
|
* @cachep: The cache to allocate from.
|
|
* @flags: See kmalloc().
|
|
* @nodeid: node number of the target node.
|
|
* @caller: return address of caller, used for debug information
|
|
*
|
|
* Identical to kmem_cache_alloc but it will allocate memory on the given
|
|
* node, which can improve the performance for cpu bound structures.
|
|
*
|
|
* Fallback to other node is possible if __GFP_THISNODE is not set.
|
|
*/
|
|
static __always_inline void *
|
|
__cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid,
|
|
void *caller)
|
|
{
|
|
unsigned long save_flags;
|
|
void *ptr;
|
|
|
|
cache_alloc_debugcheck_before(cachep, flags);
|
|
local_irq_save(save_flags);
|
|
|
|
if (unlikely(nodeid == -1))
|
|
nodeid = numa_node_id();
|
|
|
|
if (unlikely(!cachep->nodelists[nodeid])) {
|
|
/* Node not bootstrapped yet */
|
|
ptr = fallback_alloc(cachep, flags);
|
|
goto out;
|
|
}
|
|
|
|
if (nodeid == numa_node_id()) {
|
|
/*
|
|
* Use the locally cached objects if possible.
|
|
* However ____cache_alloc does not allow fallback
|
|
* to other nodes. It may fail while we still have
|
|
* objects on other nodes available.
|
|
*/
|
|
ptr = ____cache_alloc(cachep, flags);
|
|
if (ptr)
|
|
goto out;
|
|
}
|
|
/* ___cache_alloc_node can fall back to other nodes */
|
|
ptr = ____cache_alloc_node(cachep, flags, nodeid);
|
|
out:
|
|
local_irq_restore(save_flags);
|
|
ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller);
|
|
|
|
return ptr;
|
|
}
|
|
|
|
static __always_inline void *
|
|
__do_cache_alloc(struct kmem_cache *cache, gfp_t flags)
|
|
{
|
|
void *objp;
|
|
|
|
if (unlikely(current->flags & (PF_SPREAD_SLAB | PF_MEMPOLICY))) {
|
|
objp = alternate_node_alloc(cache, flags);
|
|
if (objp)
|
|
goto out;
|
|
}
|
|
objp = ____cache_alloc(cache, flags);
|
|
|
|
/*
|
|
* We may just have run out of memory on the local node.
|
|
* ____cache_alloc_node() knows how to locate memory on other nodes
|
|
*/
|
|
if (!objp)
|
|
objp = ____cache_alloc_node(cache, flags, numa_node_id());
|
|
|
|
out:
|
|
return objp;
|
|
}
|
|
#else
|
|
|
|
static __always_inline void *
|
|
__do_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
|
|
{
|
|
return ____cache_alloc(cachep, flags);
|
|
}
|
|
|
|
#endif /* CONFIG_NUMA */
|
|
|
|
static __always_inline void *
|
|
__cache_alloc(struct kmem_cache *cachep, gfp_t flags, void *caller)
|
|
{
|
|
unsigned long save_flags;
|
|
void *objp;
|
|
|
|
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);
|
|
|
|
return objp;
|
|
}
|
|
|
|
/*
|
|
* Caller needs to acquire correct kmem_list's list_lock
|
|
*/
|
|
static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects,
|
|
int node)
|
|
{
|
|
int i;
|
|
struct kmem_list3 *l3;
|
|
|
|
for (i = 0; i < nr_objects; i++) {
|
|
void *objp = objpp[i];
|
|
struct slab *slabp;
|
|
|
|
slabp = virt_to_slab(objp);
|
|
l3 = cachep->nodelists[node];
|
|
list_del(&slabp->list);
|
|
check_spinlock_acquired_node(cachep, node);
|
|
check_slabp(cachep, slabp);
|
|
slab_put_obj(cachep, slabp, objp, node);
|
|
STATS_DEC_ACTIVE(cachep);
|
|
l3->free_objects++;
|
|
check_slabp(cachep, slabp);
|
|
|
|
/* fixup slab chains */
|
|
if (slabp->inuse == 0) {
|
|
if (l3->free_objects > l3->free_limit) {
|
|
l3->free_objects -= cachep->num;
|
|
/* No need to drop any previously held
|
|
* lock here, even if we have a off-slab slab
|
|
* descriptor it is guaranteed to come from
|
|
* a different cache, refer to comments before
|
|
* alloc_slabmgmt.
|
|
*/
|
|
slab_destroy(cachep, slabp);
|
|
} else {
|
|
list_add(&slabp->list, &l3->slabs_free);
|
|
}
|
|
} else {
|
|
/* Unconditionally move a slab to the end of the
|
|
* partial list on free - maximum time for the
|
|
* other objects to be freed, too.
|
|
*/
|
|
list_add_tail(&slabp->list, &l3->slabs_partial);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac)
|
|
{
|
|
int batchcount;
|
|
struct kmem_list3 *l3;
|
|
int node = numa_node_id();
|
|
|
|
batchcount = ac->batchcount;
|
|
#if DEBUG
|
|
BUG_ON(!batchcount || batchcount > ac->avail);
|
|
#endif
|
|
check_irq_off();
|
|
l3 = cachep->nodelists[node];
|
|
spin_lock(&l3->list_lock);
|
|
if (l3->shared) {
|
|
struct array_cache *shared_array = l3->shared;
|
|
int max = shared_array->limit - shared_array->avail;
|
|
if (max) {
|
|
if (batchcount > max)
|
|
batchcount = max;
|
|
memcpy(&(shared_array->entry[shared_array->avail]),
|
|
ac->entry, sizeof(void *) * batchcount);
|
|
shared_array->avail += batchcount;
|
|
goto free_done;
|
|
}
|
|
}
|
|
|
|
free_block(cachep, ac->entry, batchcount, node);
|
|
free_done:
|
|
#if STATS
|
|
{
|
|
int i = 0;
|
|
struct list_head *p;
|
|
|
|
p = l3->slabs_free.next;
|
|
while (p != &(l3->slabs_free)) {
|
|
struct slab *slabp;
|
|
|
|
slabp = list_entry(p, struct slab, list);
|
|
BUG_ON(slabp->inuse);
|
|
|
|
i++;
|
|
p = p->next;
|
|
}
|
|
STATS_SET_FREEABLE(cachep, i);
|
|
}
|
|
#endif
|
|
spin_unlock(&l3->list_lock);
|
|
ac->avail -= batchcount;
|
|
memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail);
|
|
}
|
|
|
|
/*
|
|
* Release an obj back to its cache. If the obj has a constructed state, it must
|
|
* be in this state _before_ it is released. Called with disabled ints.
|
|
*/
|
|
static inline void __cache_free(struct kmem_cache *cachep, void *objp)
|
|
{
|
|
struct array_cache *ac = cpu_cache_get(cachep);
|
|
|
|
check_irq_off();
|
|
objp = cache_free_debugcheck(cachep, objp, __builtin_return_address(0));
|
|
|
|
if (use_alien_caches && cache_free_alien(cachep, objp))
|
|
return;
|
|
|
|
if (likely(ac->avail < ac->limit)) {
|
|
STATS_INC_FREEHIT(cachep);
|
|
ac->entry[ac->avail++] = objp;
|
|
return;
|
|
} else {
|
|
STATS_INC_FREEMISS(cachep);
|
|
cache_flusharray(cachep, ac);
|
|
ac->entry[ac->avail++] = objp;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* kmem_cache_alloc - Allocate an object
|
|
* @cachep: The cache to allocate from.
|
|
* @flags: See kmalloc().
|
|
*
|
|
* Allocate an object from this cache. The flags are only relevant
|
|
* if the cache has no available objects.
|
|
*/
|
|
void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
|
|
{
|
|
return __cache_alloc(cachep, flags, __builtin_return_address(0));
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_alloc);
|
|
|
|
/**
|
|
* kmem_cache_zalloc - Allocate an object. The memory is set to zero.
|
|
* @cache: The cache to allocate from.
|
|
* @flags: See kmalloc().
|
|
*
|
|
* Allocate an object from this cache and set the allocated memory to zero.
|
|
* The flags are only relevant if the cache has no available objects.
|
|
*/
|
|
void *kmem_cache_zalloc(struct kmem_cache *cache, gfp_t flags)
|
|
{
|
|
void *ret = __cache_alloc(cache, flags, __builtin_return_address(0));
|
|
if (ret)
|
|
memset(ret, 0, obj_size(cache));
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_zalloc);
|
|
|
|
/**
|
|
* kmem_ptr_validate - check if an untrusted pointer might
|
|
* be a slab entry.
|
|
* @cachep: the cache we're checking against
|
|
* @ptr: pointer to validate
|
|
*
|
|
* This verifies that the untrusted pointer looks sane:
|
|
* it is _not_ a guarantee that the pointer is actually
|
|
* part of the slab cache in question, but it at least
|
|
* validates that the pointer can be dereferenced and
|
|
* looks half-way sane.
|
|
*
|
|
* Currently only used for dentry validation.
|
|
*/
|
|
int kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr)
|
|
{
|
|
unsigned long addr = (unsigned long)ptr;
|
|
unsigned long min_addr = PAGE_OFFSET;
|
|
unsigned long align_mask = BYTES_PER_WORD - 1;
|
|
unsigned long size = cachep->buffer_size;
|
|
struct page *page;
|
|
|
|
if (unlikely(addr < min_addr))
|
|
goto out;
|
|
if (unlikely(addr > (unsigned long)high_memory - size))
|
|
goto out;
|
|
if (unlikely(addr & align_mask))
|
|
goto out;
|
|
if (unlikely(!kern_addr_valid(addr)))
|
|
goto out;
|
|
if (unlikely(!kern_addr_valid(addr + size - 1)))
|
|
goto out;
|
|
page = virt_to_page(ptr);
|
|
if (unlikely(!PageSlab(page)))
|
|
goto out;
|
|
if (unlikely(page_get_cache(page) != cachep))
|
|
goto out;
|
|
return 1;
|
|
out:
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_NUMA
|
|
void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
|
|
{
|
|
return __cache_alloc_node(cachep, flags, nodeid,
|
|
__builtin_return_address(0));
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_alloc_node);
|
|
|
|
static __always_inline void *
|
|
__do_kmalloc_node(size_t size, gfp_t flags, int node, void *caller)
|
|
{
|
|
struct kmem_cache *cachep;
|
|
|
|
cachep = kmem_find_general_cachep(size, flags);
|
|
if (unlikely(cachep == NULL))
|
|
return NULL;
|
|
return kmem_cache_alloc_node(cachep, flags, node);
|
|
}
|
|
|
|
#ifdef CONFIG_DEBUG_SLAB
|
|
void *__kmalloc_node(size_t size, gfp_t flags, int node)
|
|
{
|
|
return __do_kmalloc_node(size, flags, node,
|
|
__builtin_return_address(0));
|
|
}
|
|
EXPORT_SYMBOL(__kmalloc_node);
|
|
|
|
void *__kmalloc_node_track_caller(size_t size, gfp_t flags,
|
|
int node, void *caller)
|
|
{
|
|
return __do_kmalloc_node(size, flags, node, caller);
|
|
}
|
|
EXPORT_SYMBOL(__kmalloc_node_track_caller);
|
|
#else
|
|
void *__kmalloc_node(size_t size, gfp_t flags, int node)
|
|
{
|
|
return __do_kmalloc_node(size, flags, node, NULL);
|
|
}
|
|
EXPORT_SYMBOL(__kmalloc_node);
|
|
#endif /* CONFIG_DEBUG_SLAB */
|
|
#endif /* CONFIG_NUMA */
|
|
|
|
/**
|
|
* __do_kmalloc - allocate memory
|
|
* @size: how many bytes of memory are required.
|
|
* @flags: the type of memory to allocate (see kmalloc).
|
|
* @caller: function caller for debug tracking of the caller
|
|
*/
|
|
static __always_inline void *__do_kmalloc(size_t size, gfp_t flags,
|
|
void *caller)
|
|
{
|
|
struct kmem_cache *cachep;
|
|
|
|
/* If you want to save a few bytes .text space: replace
|
|
* __ with kmem_.
|
|
* Then kmalloc uses the uninlined functions instead of the inline
|
|
* functions.
|
|
*/
|
|
cachep = __find_general_cachep(size, flags);
|
|
if (unlikely(cachep == NULL))
|
|
return NULL;
|
|
return __cache_alloc(cachep, flags, caller);
|
|
}
|
|
|
|
|
|
#ifdef CONFIG_DEBUG_SLAB
|
|
void *__kmalloc(size_t size, gfp_t flags)
|
|
{
|
|
return __do_kmalloc(size, flags, __builtin_return_address(0));
|
|
}
|
|
EXPORT_SYMBOL(__kmalloc);
|
|
|
|
void *__kmalloc_track_caller(size_t size, gfp_t flags, void *caller)
|
|
{
|
|
return __do_kmalloc(size, flags, caller);
|
|
}
|
|
EXPORT_SYMBOL(__kmalloc_track_caller);
|
|
|
|
#else
|
|
void *__kmalloc(size_t size, gfp_t flags)
|
|
{
|
|
return __do_kmalloc(size, flags, NULL);
|
|
}
|
|
EXPORT_SYMBOL(__kmalloc);
|
|
#endif
|
|
|
|
/**
|
|
* kmem_cache_free - Deallocate an object
|
|
* @cachep: The cache the allocation was from.
|
|
* @objp: The previously allocated object.
|
|
*
|
|
* Free an object which was previously allocated from this
|
|
* cache.
|
|
*/
|
|
void kmem_cache_free(struct kmem_cache *cachep, void *objp)
|
|
{
|
|
unsigned long flags;
|
|
|
|
BUG_ON(virt_to_cache(objp) != cachep);
|
|
|
|
local_irq_save(flags);
|
|
debug_check_no_locks_freed(objp, obj_size(cachep));
|
|
__cache_free(cachep, objp);
|
|
local_irq_restore(flags);
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_free);
|
|
|
|
/**
|
|
* kfree - free previously allocated memory
|
|
* @objp: pointer returned by kmalloc.
|
|
*
|
|
* If @objp is NULL, no operation is performed.
|
|
*
|
|
* Don't free memory not originally allocated by kmalloc()
|
|
* or you will run into trouble.
|
|
*/
|
|
void kfree(const void *objp)
|
|
{
|
|
struct kmem_cache *c;
|
|
unsigned long flags;
|
|
|
|
if (unlikely(!objp))
|
|
return;
|
|
local_irq_save(flags);
|
|
kfree_debugcheck(objp);
|
|
c = virt_to_cache(objp);
|
|
debug_check_no_locks_freed(objp, obj_size(c));
|
|
__cache_free(c, (void *)objp);
|
|
local_irq_restore(flags);
|
|
}
|
|
EXPORT_SYMBOL(kfree);
|
|
|
|
unsigned int kmem_cache_size(struct kmem_cache *cachep)
|
|
{
|
|
return obj_size(cachep);
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_size);
|
|
|
|
const char *kmem_cache_name(struct kmem_cache *cachep)
|
|
{
|
|
return cachep->name;
|
|
}
|
|
EXPORT_SYMBOL_GPL(kmem_cache_name);
|
|
|
|
/*
|
|
* This initializes kmem_list3 or resizes varioius caches for all nodes.
|
|
*/
|
|
static int alloc_kmemlist(struct kmem_cache *cachep)
|
|
{
|
|
int node;
|
|
struct kmem_list3 *l3;
|
|
struct array_cache *new_shared;
|
|
struct array_cache **new_alien = NULL;
|
|
|
|
for_each_online_node(node) {
|
|
|
|
if (use_alien_caches) {
|
|
new_alien = alloc_alien_cache(node, cachep->limit);
|
|
if (!new_alien)
|
|
goto fail;
|
|
}
|
|
|
|
new_shared = alloc_arraycache(node,
|
|
cachep->shared*cachep->batchcount,
|
|
0xbaadf00d);
|
|
if (!new_shared) {
|
|
free_alien_cache(new_alien);
|
|
goto fail;
|
|
}
|
|
|
|
l3 = cachep->nodelists[node];
|
|
if (l3) {
|
|
struct array_cache *shared = l3->shared;
|
|
|
|
spin_lock_irq(&l3->list_lock);
|
|
|
|
if (shared)
|
|
free_block(cachep, shared->entry,
|
|
shared->avail, node);
|
|
|
|
l3->shared = new_shared;
|
|
if (!l3->alien) {
|
|
l3->alien = new_alien;
|
|
new_alien = NULL;
|
|
}
|
|
l3->free_limit = (1 + nr_cpus_node(node)) *
|
|
cachep->batchcount + cachep->num;
|
|
spin_unlock_irq(&l3->list_lock);
|
|
kfree(shared);
|
|
free_alien_cache(new_alien);
|
|
continue;
|
|
}
|
|
l3 = kmalloc_node(sizeof(struct kmem_list3), GFP_KERNEL, node);
|
|
if (!l3) {
|
|
free_alien_cache(new_alien);
|
|
kfree(new_shared);
|
|
goto fail;
|
|
}
|
|
|
|
kmem_list3_init(l3);
|
|
l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
|
|
((unsigned long)cachep) % REAPTIMEOUT_LIST3;
|
|
l3->shared = new_shared;
|
|
l3->alien = new_alien;
|
|
l3->free_limit = (1 + nr_cpus_node(node)) *
|
|
cachep->batchcount + cachep->num;
|
|
cachep->nodelists[node] = l3;
|
|
}
|
|
return 0;
|
|
|
|
fail:
|
|
if (!cachep->next.next) {
|
|
/* Cache is not active yet. Roll back what we did */
|
|
node--;
|
|
while (node >= 0) {
|
|
if (cachep->nodelists[node]) {
|
|
l3 = cachep->nodelists[node];
|
|
|
|
kfree(l3->shared);
|
|
free_alien_cache(l3->alien);
|
|
kfree(l3);
|
|
cachep->nodelists[node] = NULL;
|
|
}
|
|
node--;
|
|
}
|
|
}
|
|
return -ENOMEM;
|
|
}
|
|
|
|
struct ccupdate_struct {
|
|
struct kmem_cache *cachep;
|
|
struct array_cache *new[NR_CPUS];
|
|
};
|
|
|
|
static void do_ccupdate_local(void *info)
|
|
{
|
|
struct ccupdate_struct *new = info;
|
|
struct array_cache *old;
|
|
|
|
check_irq_off();
|
|
old = cpu_cache_get(new->cachep);
|
|
|
|
new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()];
|
|
new->new[smp_processor_id()] = old;
|
|
}
|
|
|
|
/* Always called with the cache_chain_mutex held */
|
|
static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
|
|
int batchcount, int shared)
|
|
{
|
|
struct ccupdate_struct *new;
|
|
int i;
|
|
|
|
new = kzalloc(sizeof(*new), GFP_KERNEL);
|
|
if (!new)
|
|
return -ENOMEM;
|
|
|
|
for_each_online_cpu(i) {
|
|
new->new[i] = alloc_arraycache(cpu_to_node(i), limit,
|
|
batchcount);
|
|
if (!new->new[i]) {
|
|
for (i--; i >= 0; i--)
|
|
kfree(new->new[i]);
|
|
kfree(new);
|
|
return -ENOMEM;
|
|
}
|
|
}
|
|
new->cachep = cachep;
|
|
|
|
on_each_cpu(do_ccupdate_local, (void *)new, 1, 1);
|
|
|
|
check_irq_on();
|
|
cachep->batchcount = batchcount;
|
|
cachep->limit = limit;
|
|
cachep->shared = shared;
|
|
|
|
for_each_online_cpu(i) {
|
|
struct array_cache *ccold = new->new[i];
|
|
if (!ccold)
|
|
continue;
|
|
spin_lock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
|
|
free_block(cachep, ccold->entry, ccold->avail, cpu_to_node(i));
|
|
spin_unlock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
|
|
kfree(ccold);
|
|
}
|
|
kfree(new);
|
|
return alloc_kmemlist(cachep);
|
|
}
|
|
|
|
/* Called with cache_chain_mutex held always */
|
|
static int enable_cpucache(struct kmem_cache *cachep)
|
|
{
|
|
int err;
|
|
int limit, shared;
|
|
|
|
/*
|
|
* The head array serves three purposes:
|
|
* - create a LIFO ordering, i.e. return objects that are cache-warm
|
|
* - reduce the number of spinlock operations.
|
|
* - reduce the number of linked list operations on the slab and
|
|
* bufctl chains: array operations are cheaper.
|
|
* The numbers are guessed, we should auto-tune as described by
|
|
* Bonwick.
|
|
*/
|
|
if (cachep->buffer_size > 131072)
|
|
limit = 1;
|
|
else if (cachep->buffer_size > PAGE_SIZE)
|
|
limit = 8;
|
|
else if (cachep->buffer_size > 1024)
|
|
limit = 24;
|
|
else if (cachep->buffer_size > 256)
|
|
limit = 54;
|
|
else
|
|
limit = 120;
|
|
|
|
/*
|
|
* CPU bound tasks (e.g. network routing) can exhibit cpu bound
|
|
* allocation behaviour: Most allocs on one cpu, most free operations
|
|
* on another cpu. For these cases, an efficient object passing between
|
|
* cpus is necessary. This is provided by a shared array. The array
|
|
* replaces Bonwick's magazine layer.
|
|
* On uniprocessor, it's functionally equivalent (but less efficient)
|
|
* to a larger limit. Thus disabled by default.
|
|
*/
|
|
shared = 0;
|
|
#ifdef CONFIG_SMP
|
|
if (cachep->buffer_size <= PAGE_SIZE)
|
|
shared = 8;
|
|
#endif
|
|
|
|
#if DEBUG
|
|
/*
|
|
* With debugging enabled, large batchcount lead to excessively long
|
|
* periods with disabled local interrupts. Limit the batchcount
|
|
*/
|
|
if (limit > 32)
|
|
limit = 32;
|
|
#endif
|
|
err = do_tune_cpucache(cachep, limit, (limit + 1) / 2, shared);
|
|
if (err)
|
|
printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n",
|
|
cachep->name, -err);
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Drain an array if it contains any elements taking the l3 lock only if
|
|
* necessary. Note that the l3 listlock also protects the array_cache
|
|
* if drain_array() is used on the shared array.
|
|
*/
|
|
void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3,
|
|
struct array_cache *ac, int force, int node)
|
|
{
|
|
int tofree;
|
|
|
|
if (!ac || !ac->avail)
|
|
return;
|
|
if (ac->touched && !force) {
|
|
ac->touched = 0;
|
|
} else {
|
|
spin_lock_irq(&l3->list_lock);
|
|
if (ac->avail) {
|
|
tofree = force ? ac->avail : (ac->limit + 4) / 5;
|
|
if (tofree > ac->avail)
|
|
tofree = (ac->avail + 1) / 2;
|
|
free_block(cachep, ac->entry, tofree, node);
|
|
ac->avail -= tofree;
|
|
memmove(ac->entry, &(ac->entry[tofree]),
|
|
sizeof(void *) * ac->avail);
|
|
}
|
|
spin_unlock_irq(&l3->list_lock);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* cache_reap - Reclaim memory from caches.
|
|
* @w: work descriptor
|
|
*
|
|
* Called from workqueue/eventd every few seconds.
|
|
* Purpose:
|
|
* - clear the per-cpu caches for this CPU.
|
|
* - return freeable pages to the main free memory pool.
|
|
*
|
|
* If we cannot acquire the cache chain mutex then just give up - we'll try
|
|
* again on the next iteration.
|
|
*/
|
|
static void cache_reap(struct work_struct *w)
|
|
{
|
|
struct kmem_cache *searchp;
|
|
struct kmem_list3 *l3;
|
|
int node = numa_node_id();
|
|
struct delayed_work *work =
|
|
container_of(w, struct delayed_work, work);
|
|
|
|
if (!mutex_trylock(&cache_chain_mutex))
|
|
/* Give up. Setup the next iteration. */
|
|
goto out;
|
|
|
|
list_for_each_entry(searchp, &cache_chain, next) {
|
|
check_irq_on();
|
|
|
|
/*
|
|
* We only take the l3 lock if absolutely necessary and we
|
|
* have established with reasonable certainty that
|
|
* we can do some work if the lock was obtained.
|
|
*/
|
|
l3 = searchp->nodelists[node];
|
|
|
|
reap_alien(searchp, l3);
|
|
|
|
drain_array(searchp, l3, cpu_cache_get(searchp), 0, node);
|
|
|
|
/*
|
|
* These are racy checks but it does not matter
|
|
* if we skip one check or scan twice.
|
|
*/
|
|
if (time_after(l3->next_reap, jiffies))
|
|
goto next;
|
|
|
|
l3->next_reap = jiffies + REAPTIMEOUT_LIST3;
|
|
|
|
drain_array(searchp, l3, l3->shared, 0, node);
|
|
|
|
if (l3->free_touched)
|
|
l3->free_touched = 0;
|
|
else {
|
|
int freed;
|
|
|
|
freed = drain_freelist(searchp, l3, (l3->free_limit +
|
|
5 * searchp->num - 1) / (5 * searchp->num));
|
|
STATS_ADD_REAPED(searchp, freed);
|
|
}
|
|
next:
|
|
cond_resched();
|
|
}
|
|
check_irq_on();
|
|
mutex_unlock(&cache_chain_mutex);
|
|
next_reap_node();
|
|
refresh_cpu_vm_stats(smp_processor_id());
|
|
out:
|
|
/* Set up the next iteration */
|
|
schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_CPUC));
|
|
}
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
|
|
static void print_slabinfo_header(struct seq_file *m)
|
|
{
|
|
/*
|
|
* Output format version, so at least we can change it
|
|
* without _too_ many complaints.
|
|
*/
|
|
#if STATS
|
|
seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
|
|
#else
|
|
seq_puts(m, "slabinfo - version: 2.1\n");
|
|
#endif
|
|
seq_puts(m, "# name <active_objs> <num_objs> <objsize> "
|
|
"<objperslab> <pagesperslab>");
|
|
seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
|
|
seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
|
|
#if STATS
|
|
seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> "
|
|
"<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
|
|
seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
|
|
#endif
|
|
seq_putc(m, '\n');
|
|
}
|
|
|
|
static void *s_start(struct seq_file *m, loff_t *pos)
|
|
{
|
|
loff_t n = *pos;
|
|
struct list_head *p;
|
|
|
|
mutex_lock(&cache_chain_mutex);
|
|
if (!n)
|
|
print_slabinfo_header(m);
|
|
p = cache_chain.next;
|
|
while (n--) {
|
|
p = p->next;
|
|
if (p == &cache_chain)
|
|
return NULL;
|
|
}
|
|
return list_entry(p, struct kmem_cache, next);
|
|
}
|
|
|
|
static void *s_next(struct seq_file *m, void *p, loff_t *pos)
|
|
{
|
|
struct kmem_cache *cachep = p;
|
|
++*pos;
|
|
return cachep->next.next == &cache_chain ?
|
|
NULL : list_entry(cachep->next.next, struct kmem_cache, next);
|
|
}
|
|
|
|
static void s_stop(struct seq_file *m, void *p)
|
|
{
|
|
mutex_unlock(&cache_chain_mutex);
|
|
}
|
|
|
|
static int s_show(struct seq_file *m, void *p)
|
|
{
|
|
struct kmem_cache *cachep = p;
|
|
struct slab *slabp;
|
|
unsigned long active_objs;
|
|
unsigned long num_objs;
|
|
unsigned long active_slabs = 0;
|
|
unsigned long num_slabs, free_objects = 0, shared_avail = 0;
|
|
const char *name;
|
|
char *error = NULL;
|
|
int node;
|
|
struct kmem_list3 *l3;
|
|
|
|
active_objs = 0;
|
|
num_slabs = 0;
|
|
for_each_online_node(node) {
|
|
l3 = cachep->nodelists[node];
|
|
if (!l3)
|
|
continue;
|
|
|
|
check_irq_on();
|
|
spin_lock_irq(&l3->list_lock);
|
|
|
|
list_for_each_entry(slabp, &l3->slabs_full, list) {
|
|
if (slabp->inuse != cachep->num && !error)
|
|
error = "slabs_full accounting error";
|
|
active_objs += cachep->num;
|
|
active_slabs++;
|
|
}
|
|
list_for_each_entry(slabp, &l3->slabs_partial, list) {
|
|
if (slabp->inuse == cachep->num && !error)
|
|
error = "slabs_partial inuse accounting error";
|
|
if (!slabp->inuse && !error)
|
|
error = "slabs_partial/inuse accounting error";
|
|
active_objs += slabp->inuse;
|
|
active_slabs++;
|
|
}
|
|
list_for_each_entry(slabp, &l3->slabs_free, list) {
|
|
if (slabp->inuse && !error)
|
|
error = "slabs_free/inuse accounting error";
|
|
num_slabs++;
|
|
}
|
|
free_objects += l3->free_objects;
|
|
if (l3->shared)
|
|
shared_avail += l3->shared->avail;
|
|
|
|
spin_unlock_irq(&l3->list_lock);
|
|
}
|
|
num_slabs += active_slabs;
|
|
num_objs = num_slabs * cachep->num;
|
|
if (num_objs - active_objs != free_objects && !error)
|
|
error = "free_objects accounting error";
|
|
|
|
name = cachep->name;
|
|
if (error)
|
|
printk(KERN_ERR "slab: cache %s error: %s\n", name, error);
|
|
|
|
seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
|
|
name, active_objs, num_objs, cachep->buffer_size,
|
|
cachep->num, (1 << cachep->gfporder));
|
|
seq_printf(m, " : tunables %4u %4u %4u",
|
|
cachep->limit, cachep->batchcount, cachep->shared);
|
|
seq_printf(m, " : slabdata %6lu %6lu %6lu",
|
|
active_slabs, num_slabs, shared_avail);
|
|
#if STATS
|
|
{ /* list3 stats */
|
|
unsigned long high = cachep->high_mark;
|
|
unsigned long allocs = cachep->num_allocations;
|
|
unsigned long grown = cachep->grown;
|
|
unsigned long reaped = cachep->reaped;
|
|
unsigned long errors = cachep->errors;
|
|
unsigned long max_freeable = cachep->max_freeable;
|
|
unsigned long node_allocs = cachep->node_allocs;
|
|
unsigned long node_frees = cachep->node_frees;
|
|
unsigned long overflows = cachep->node_overflow;
|
|
|
|
seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu \
|
|
%4lu %4lu %4lu %4lu %4lu", allocs, high, grown,
|
|
reaped, errors, max_freeable, node_allocs,
|
|
node_frees, overflows);
|
|
}
|
|
/* cpu stats */
|
|
{
|
|
unsigned long allochit = atomic_read(&cachep->allochit);
|
|
unsigned long allocmiss = atomic_read(&cachep->allocmiss);
|
|
unsigned long freehit = atomic_read(&cachep->freehit);
|
|
unsigned long freemiss = atomic_read(&cachep->freemiss);
|
|
|
|
seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu",
|
|
allochit, allocmiss, freehit, freemiss);
|
|
}
|
|
#endif
|
|
seq_putc(m, '\n');
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* slabinfo_op - iterator that generates /proc/slabinfo
|
|
*
|
|
* Output layout:
|
|
* cache-name
|
|
* num-active-objs
|
|
* total-objs
|
|
* object size
|
|
* num-active-slabs
|
|
* total-slabs
|
|
* num-pages-per-slab
|
|
* + further values on SMP and with statistics enabled
|
|
*/
|
|
|
|
const struct seq_operations slabinfo_op = {
|
|
.start = s_start,
|
|
.next = s_next,
|
|
.stop = s_stop,
|
|
.show = s_show,
|
|
};
|
|
|
|
#define MAX_SLABINFO_WRITE 128
|
|
/**
|
|
* slabinfo_write - Tuning for the slab allocator
|
|
* @file: unused
|
|
* @buffer: user buffer
|
|
* @count: data length
|
|
* @ppos: unused
|
|
*/
|
|
ssize_t slabinfo_write(struct file *file, const char __user * buffer,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
char kbuf[MAX_SLABINFO_WRITE + 1], *tmp;
|
|
int limit, batchcount, shared, res;
|
|
struct kmem_cache *cachep;
|
|
|
|
if (count > MAX_SLABINFO_WRITE)
|
|
return -EINVAL;
|
|
if (copy_from_user(&kbuf, buffer, count))
|
|
return -EFAULT;
|
|
kbuf[MAX_SLABINFO_WRITE] = '\0';
|
|
|
|
tmp = strchr(kbuf, ' ');
|
|
if (!tmp)
|
|
return -EINVAL;
|
|
*tmp = '\0';
|
|
tmp++;
|
|
if (sscanf(tmp, " %d %d %d", &limit, &batchcount, &shared) != 3)
|
|
return -EINVAL;
|
|
|
|
/* Find the cache in the chain of caches. */
|
|
mutex_lock(&cache_chain_mutex);
|
|
res = -EINVAL;
|
|
list_for_each_entry(cachep, &cache_chain, next) {
|
|
if (!strcmp(cachep->name, kbuf)) {
|
|
if (limit < 1 || batchcount < 1 ||
|
|
batchcount > limit || shared < 0) {
|
|
res = 0;
|
|
} else {
|
|
res = do_tune_cpucache(cachep, limit,
|
|
batchcount, shared);
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
mutex_unlock(&cache_chain_mutex);
|
|
if (res >= 0)
|
|
res = count;
|
|
return res;
|
|
}
|
|
|
|
#ifdef CONFIG_DEBUG_SLAB_LEAK
|
|
|
|
static void *leaks_start(struct seq_file *m, loff_t *pos)
|
|
{
|
|
loff_t n = *pos;
|
|
struct list_head *p;
|
|
|
|
mutex_lock(&cache_chain_mutex);
|
|
p = cache_chain.next;
|
|
while (n--) {
|
|
p = p->next;
|
|
if (p == &cache_chain)
|
|
return NULL;
|
|
}
|
|
return list_entry(p, struct kmem_cache, next);
|
|
}
|
|
|
|
static inline int add_caller(unsigned long *n, unsigned long v)
|
|
{
|
|
unsigned long *p;
|
|
int l;
|
|
if (!v)
|
|
return 1;
|
|
l = n[1];
|
|
p = n + 2;
|
|
while (l) {
|
|
int i = l/2;
|
|
unsigned long *q = p + 2 * i;
|
|
if (*q == v) {
|
|
q[1]++;
|
|
return 1;
|
|
}
|
|
if (*q > v) {
|
|
l = i;
|
|
} else {
|
|
p = q + 2;
|
|
l -= i + 1;
|
|
}
|
|
}
|
|
if (++n[1] == n[0])
|
|
return 0;
|
|
memmove(p + 2, p, n[1] * 2 * sizeof(unsigned long) - ((void *)p - (void *)n));
|
|
p[0] = v;
|
|
p[1] = 1;
|
|
return 1;
|
|
}
|
|
|
|
static void handle_slab(unsigned long *n, struct kmem_cache *c, struct slab *s)
|
|
{
|
|
void *p;
|
|
int i;
|
|
if (n[0] == n[1])
|
|
return;
|
|
for (i = 0, p = s->s_mem; i < c->num; i++, p += c->buffer_size) {
|
|
if (slab_bufctl(s)[i] != BUFCTL_ACTIVE)
|
|
continue;
|
|
if (!add_caller(n, (unsigned long)*dbg_userword(c, p)))
|
|
return;
|
|
}
|
|
}
|
|
|
|
static void show_symbol(struct seq_file *m, unsigned long address)
|
|
{
|
|
#ifdef CONFIG_KALLSYMS
|
|
char *modname;
|
|
const char *name;
|
|
unsigned long offset, size;
|
|
char namebuf[KSYM_NAME_LEN+1];
|
|
|
|
name = kallsyms_lookup(address, &size, &offset, &modname, namebuf);
|
|
|
|
if (name) {
|
|
seq_printf(m, "%s+%#lx/%#lx", name, offset, size);
|
|
if (modname)
|
|
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 = p;
|
|
struct slab *slabp;
|
|
struct kmem_list3 *l3;
|
|
const char *name;
|
|
unsigned long *n = m->private;
|
|
int node;
|
|
int i;
|
|
|
|
if (!(cachep->flags & SLAB_STORE_USER))
|
|
return 0;
|
|
if (!(cachep->flags & SLAB_RED_ZONE))
|
|
return 0;
|
|
|
|
/* OK, we can do it */
|
|
|
|
n[1] = 0;
|
|
|
|
for_each_online_node(node) {
|
|
l3 = cachep->nodelists[node];
|
|
if (!l3)
|
|
continue;
|
|
|
|
check_irq_on();
|
|
spin_lock_irq(&l3->list_lock);
|
|
|
|
list_for_each_entry(slabp, &l3->slabs_full, list)
|
|
handle_slab(n, cachep, slabp);
|
|
list_for_each_entry(slabp, &l3->slabs_partial, list)
|
|
handle_slab(n, cachep, slabp);
|
|
spin_unlock_irq(&l3->list_lock);
|
|
}
|
|
name = cachep->name;
|
|
if (n[0] == n[1]) {
|
|
/* Increase the buffer size */
|
|
mutex_unlock(&cache_chain_mutex);
|
|
m->private = kzalloc(n[0] * 4 * sizeof(unsigned long), GFP_KERNEL);
|
|
if (!m->private) {
|
|
/* Too bad, we are really out */
|
|
m->private = n;
|
|
mutex_lock(&cache_chain_mutex);
|
|
return -ENOMEM;
|
|
}
|
|
*(unsigned long *)m->private = n[0] * 2;
|
|
kfree(n);
|
|
mutex_lock(&cache_chain_mutex);
|
|
/* Now make sure this entry will be retried */
|
|
m->count = m->size;
|
|
return 0;
|
|
}
|
|
for (i = 0; i < n[1]; i++) {
|
|
seq_printf(m, "%s: %lu ", name, n[2*i+3]);
|
|
show_symbol(m, n[2*i+2]);
|
|
seq_putc(m, '\n');
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
const struct seq_operations slabstats_op = {
|
|
.start = leaks_start,
|
|
.next = s_next,
|
|
.stop = s_stop,
|
|
.show = leaks_show,
|
|
};
|
|
#endif
|
|
#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.
|
|
*/
|
|
unsigned int ksize(const void *objp)
|
|
{
|
|
if (unlikely(objp == NULL))
|
|
return 0;
|
|
|
|
return obj_size(virt_to_cache(objp));
|
|
}
|