diff options
author | Fathi Boudra <fathi.boudra@linaro.org> | 2013-04-28 09:33:08 +0300 |
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committer | Fathi Boudra <fathi.boudra@linaro.org> | 2013-04-28 09:33:08 +0300 |
commit | 3b4bd47f8f4ed3aaf7c81c9b5d2d37ad79fadf4a (patch) | |
tree | b9996006addfd7ae70a39672b76843b49aebc189 /mm/slab_common.c |
Imported Upstream version 3.9.0HEADupstream/3.9.0upstreammaster
Diffstat (limited to 'mm/slab_common.c')
-rw-r--r-- | mm/slab_common.c | 466 |
1 files changed, 466 insertions, 0 deletions
diff --git a/mm/slab_common.c b/mm/slab_common.c new file mode 100644 index 00000000..3f3cd97d --- /dev/null +++ b/mm/slab_common.c @@ -0,0 +1,466 @@ +/* + * Slab allocator functions that are independent of the allocator strategy + * + * (C) 2012 Christoph Lameter <cl@linux.com> + */ +#include <linux/slab.h> + +#include <linux/mm.h> +#include <linux/poison.h> +#include <linux/interrupt.h> +#include <linux/memory.h> +#include <linux/compiler.h> +#include <linux/module.h> +#include <linux/cpu.h> +#include <linux/uaccess.h> +#include <linux/seq_file.h> +#include <linux/proc_fs.h> +#include <asm/cacheflush.h> +#include <asm/tlbflush.h> +#include <asm/page.h> +#include <linux/memcontrol.h> + +#include "slab.h" + +enum slab_state slab_state; +LIST_HEAD(slab_caches); +DEFINE_MUTEX(slab_mutex); +struct kmem_cache *kmem_cache; + +#ifdef CONFIG_DEBUG_VM +static int kmem_cache_sanity_check(struct mem_cgroup *memcg, const char *name, + size_t size) +{ + struct kmem_cache *s = NULL; + + if (!name || in_interrupt() || size < sizeof(void *) || + size > KMALLOC_MAX_SIZE) { + pr_err("kmem_cache_create(%s) integrity check failed\n", name); + return -EINVAL; + } + + list_for_each_entry(s, &slab_caches, list) { + 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(s->name, tmp); + if (res) { + pr_err("Slab cache with size %d has lost its name\n", + s->object_size); + continue; + } + + /* + * For simplicity, we won't check this in the list of memcg + * caches. We have control over memcg naming, and if there + * aren't duplicates in the global list, there won't be any + * duplicates in the memcg lists as well. + */ + if (!memcg && !strcmp(s->name, name)) { + pr_err("%s (%s): Cache name already exists.\n", + __func__, name); + dump_stack(); + s = NULL; + return -EINVAL; + } + } + + WARN_ON(strchr(name, ' ')); /* It confuses parsers */ + return 0; +} +#else +static inline int kmem_cache_sanity_check(struct mem_cgroup *memcg, + const char *name, size_t size) +{ + return 0; +} +#endif + +#ifdef CONFIG_MEMCG_KMEM +int memcg_update_all_caches(int num_memcgs) +{ + struct kmem_cache *s; + int ret = 0; + mutex_lock(&slab_mutex); + + list_for_each_entry(s, &slab_caches, list) { + if (!is_root_cache(s)) + continue; + + ret = memcg_update_cache_size(s, num_memcgs); + /* + * See comment in memcontrol.c, memcg_update_cache_size: + * Instead of freeing the memory, we'll just leave the caches + * up to this point in an updated state. + */ + if (ret) + goto out; + } + + memcg_update_array_size(num_memcgs); +out: + mutex_unlock(&slab_mutex); + return ret; +} +#endif + +/* + * Figure out what the alignment of the objects will be given a set of + * flags, a user specified alignment and the size of the objects. + */ +unsigned long calculate_alignment(unsigned long flags, + unsigned long align, unsigned long size) +{ + /* + * If the user wants hardware cache aligned objects then follow that + * suggestion if the object is sufficiently large. + * + * The hardware cache alignment cannot override the specified + * alignment though. If that is greater then use it. + */ + if (flags & SLAB_HWCACHE_ALIGN) { + unsigned long ralign = cache_line_size(); + while (size <= ralign / 2) + ralign /= 2; + align = max(align, ralign); + } + + if (align < ARCH_SLAB_MINALIGN) + align = ARCH_SLAB_MINALIGN; + + return ALIGN(align, sizeof(void *)); +} + + +/* + * kmem_cache_create - Create a cache. + * @name: A string which is used in /proc/slabinfo to identify this cache. + * @size: The size of objects to be created in this cache. + * @align: The required alignment for the objects. + * @flags: SLAB flags + * @ctor: A constructor for the objects. + * + * Returns a ptr to the cache on success, NULL on failure. + * Cannot be called within a interrupt, but can be interrupted. + * The @ctor is run when new pages are allocated by the cache. + * + * The flags are + * + * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) + * to catch references to uninitialised memory. + * + * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check + * for buffer overruns. + * + * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware + * cacheline. This can be beneficial if you're counting cycles as closely + * as davem. + */ + +struct kmem_cache * +kmem_cache_create_memcg(struct mem_cgroup *memcg, const char *name, size_t size, + size_t align, unsigned long flags, void (*ctor)(void *), + struct kmem_cache *parent_cache) +{ + struct kmem_cache *s = NULL; + int err = 0; + + get_online_cpus(); + mutex_lock(&slab_mutex); + + if (!kmem_cache_sanity_check(memcg, name, size) == 0) + goto out_locked; + + /* + * Some allocators will constraint the set of valid flags to a subset + * of all flags. We expect them to define CACHE_CREATE_MASK in this + * case, and we'll just provide them with a sanitized version of the + * passed flags. + */ + flags &= CACHE_CREATE_MASK; + + s = __kmem_cache_alias(memcg, name, size, align, flags, ctor); + if (s) + goto out_locked; + + s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL); + if (s) { + s->object_size = s->size = size; + s->align = calculate_alignment(flags, align, size); + s->ctor = ctor; + + if (memcg_register_cache(memcg, s, parent_cache)) { + kmem_cache_free(kmem_cache, s); + err = -ENOMEM; + goto out_locked; + } + + s->name = kstrdup(name, GFP_KERNEL); + if (!s->name) { + kmem_cache_free(kmem_cache, s); + err = -ENOMEM; + goto out_locked; + } + + err = __kmem_cache_create(s, flags); + if (!err) { + s->refcount = 1; + list_add(&s->list, &slab_caches); + memcg_cache_list_add(memcg, s); + } else { + kfree(s->name); + kmem_cache_free(kmem_cache, s); + } + } else + err = -ENOMEM; + +out_locked: + mutex_unlock(&slab_mutex); + put_online_cpus(); + + if (err) { + + if (flags & SLAB_PANIC) + panic("kmem_cache_create: Failed to create slab '%s'. Error %d\n", + name, err); + else { + printk(KERN_WARNING "kmem_cache_create(%s) failed with error %d", + name, err); + dump_stack(); + } + + return NULL; + } + + return s; +} + +struct kmem_cache * +kmem_cache_create(const char *name, size_t size, size_t align, + unsigned long flags, void (*ctor)(void *)) +{ + return kmem_cache_create_memcg(NULL, name, size, align, flags, ctor, NULL); +} +EXPORT_SYMBOL(kmem_cache_create); + +void kmem_cache_destroy(struct kmem_cache *s) +{ + /* Destroy all the children caches if we aren't a memcg cache */ + kmem_cache_destroy_memcg_children(s); + + get_online_cpus(); + mutex_lock(&slab_mutex); + s->refcount--; + if (!s->refcount) { + list_del(&s->list); + + if (!__kmem_cache_shutdown(s)) { + mutex_unlock(&slab_mutex); + if (s->flags & SLAB_DESTROY_BY_RCU) + rcu_barrier(); + + memcg_release_cache(s); + kfree(s->name); + kmem_cache_free(kmem_cache, s); + } else { + list_add(&s->list, &slab_caches); + mutex_unlock(&slab_mutex); + printk(KERN_ERR "kmem_cache_destroy %s: Slab cache still has objects\n", + s->name); + dump_stack(); + } + } else { + mutex_unlock(&slab_mutex); + } + put_online_cpus(); +} +EXPORT_SYMBOL(kmem_cache_destroy); + +int slab_is_available(void) +{ + return slab_state >= UP; +} + +#ifndef CONFIG_SLOB +/* Create a cache during boot when no slab services are available yet */ +void __init create_boot_cache(struct kmem_cache *s, const char *name, size_t size, + unsigned long flags) +{ + int err; + + s->name = name; + s->size = s->object_size = size; + s->align = calculate_alignment(flags, ARCH_KMALLOC_MINALIGN, size); + err = __kmem_cache_create(s, flags); + + if (err) + panic("Creation of kmalloc slab %s size=%zd failed. Reason %d\n", + name, size, err); + + s->refcount = -1; /* Exempt from merging for now */ +} + +struct kmem_cache *__init create_kmalloc_cache(const char *name, size_t size, + unsigned long flags) +{ + struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT); + + if (!s) + panic("Out of memory when creating slab %s\n", name); + + create_boot_cache(s, name, size, flags); + list_add(&s->list, &slab_caches); + s->refcount = 1; + return s; +} + +#endif /* !CONFIG_SLOB */ + + +#ifdef CONFIG_SLABINFO +void print_slabinfo_header(struct seq_file *m) +{ + /* + * Output format version, so at least we can change it + * without _too_ many complaints. + */ +#ifdef CONFIG_DEBUG_SLAB + 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>"); +#ifdef CONFIG_DEBUG_SLAB + seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> " + "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>"); + seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>"); +#endif + seq_putc(m, '\n'); +} + +static void *s_start(struct seq_file *m, loff_t *pos) +{ + loff_t n = *pos; + + mutex_lock(&slab_mutex); + if (!n) + print_slabinfo_header(m); + + return seq_list_start(&slab_caches, *pos); +} + +static void *s_next(struct seq_file *m, void *p, loff_t *pos) +{ + return seq_list_next(p, &slab_caches, pos); +} + +static void s_stop(struct seq_file *m, void *p) +{ + mutex_unlock(&slab_mutex); +} + +static void +memcg_accumulate_slabinfo(struct kmem_cache *s, struct slabinfo *info) +{ + struct kmem_cache *c; + struct slabinfo sinfo; + int i; + + if (!is_root_cache(s)) + return; + + for_each_memcg_cache_index(i) { + c = cache_from_memcg(s, i); + if (!c) + continue; + + memset(&sinfo, 0, sizeof(sinfo)); + get_slabinfo(c, &sinfo); + + info->active_slabs += sinfo.active_slabs; + info->num_slabs += sinfo.num_slabs; + info->shared_avail += sinfo.shared_avail; + info->active_objs += sinfo.active_objs; + info->num_objs += sinfo.num_objs; + } +} + +int cache_show(struct kmem_cache *s, struct seq_file *m) +{ + struct slabinfo sinfo; + + memset(&sinfo, 0, sizeof(sinfo)); + get_slabinfo(s, &sinfo); + + memcg_accumulate_slabinfo(s, &sinfo); + + seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", + cache_name(s), sinfo.active_objs, sinfo.num_objs, s->size, + sinfo.objects_per_slab, (1 << sinfo.cache_order)); + + seq_printf(m, " : tunables %4u %4u %4u", + sinfo.limit, sinfo.batchcount, sinfo.shared); + seq_printf(m, " : slabdata %6lu %6lu %6lu", + sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail); + slabinfo_show_stats(m, s); + seq_putc(m, '\n'); + return 0; +} + +static int s_show(struct seq_file *m, void *p) +{ + struct kmem_cache *s = list_entry(p, struct kmem_cache, list); + + if (!is_root_cache(s)) + return 0; + return cache_show(s, m); +} + +/* + * 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 + */ +static const struct seq_operations slabinfo_op = { + .start = s_start, + .next = s_next, + .stop = s_stop, + .show = s_show, +}; + +static int slabinfo_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &slabinfo_op); +} + +static const struct file_operations proc_slabinfo_operations = { + .open = slabinfo_open, + .read = seq_read, + .write = slabinfo_write, + .llseek = seq_lseek, + .release = seq_release, +}; + +static int __init slab_proc_init(void) +{ + proc_create("slabinfo", S_IRUSR, NULL, &proc_slabinfo_operations); + return 0; +} +module_init(slab_proc_init); +#endif /* CONFIG_SLABINFO */ |