Commit 871751e2 authored by Al Viro's avatar Al Viro Committed by Linus Torvalds
Browse files

[PATCH] slab: implement /proc/slab_allocators



Implement /proc/slab_allocators.   It produces output like:

idr_layer_cache: 80 idr_pre_get+0x33/0x4e
buffer_head: 2555 alloc_buffer_head+0x20/0x75
mm_struct: 9 mm_alloc+0x1e/0x42
mm_struct: 20 dup_mm+0x36/0x370
vm_area_struct: 384 dup_mm+0x18f/0x370
vm_area_struct: 151 do_mmap_pgoff+0x2e0/0x7c3
vm_area_struct: 1 split_vma+0x5a/0x10e
vm_area_struct: 11 do_brk+0x206/0x2e2
vm_area_struct: 2 copy_vma+0xda/0x142
vm_area_struct: 9 setup_arg_pages+0x99/0x214
fs_cache: 8 copy_fs_struct+0x21/0x133
fs_cache: 29 copy_process+0xf38/0x10e3
files_cache: 30 alloc_files+0x1b/0xcf
signal_cache: 81 copy_process+0xbaa/0x10e3
sighand_cache: 77 copy_process+0xe65/0x10e3
sighand_cache: 1 de_thread+0x4d/0x5f8
anon_vma: 241 anon_vma_prepare+0xd9/0xf3
size-2048: 1 add_sect_attrs+0x5f/0x145
size-2048: 2 journal_init_revoke+0x99/0x302
size-2048: 2 journal_init_revoke+0x137/0x302
size-2048: 2 journal_init_inode+0xf9/0x1c4

Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Alexander Nyberg <alexn@telia.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
DESC
slab-leaks3-locking-fix
EDESC
From: Andrew Morton <akpm@osdl.org>

Update for slab-remove-cachep-spinlock.patch

Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Alexander Nyberg <alexn@telia.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent f52ac8fe
......@@ -485,6 +485,40 @@ static struct file_operations proc_slabinfo_operations = {
.llseek = seq_lseek,
.release = seq_release,
};
#ifdef CONFIG_DEBUG_SLAB_LEAK
extern struct seq_operations slabstats_op;
static int slabstats_open(struct inode *inode, struct file *file)
{
unsigned long *n = kzalloc(PAGE_SIZE, GFP_KERNEL);
int ret = -ENOMEM;
if (n) {
ret = seq_open(file, &slabstats_op);
if (!ret) {
struct seq_file *m = file->private_data;
*n = PAGE_SIZE / (2 * sizeof(unsigned long));
m->private = n;
n = NULL;
}
kfree(n);
}
return ret;
}
static int slabstats_release(struct inode *inode, struct file *file)
{
struct seq_file *m = file->private_data;
kfree(m->private);
return seq_release(inode, file);
}
static struct file_operations proc_slabstats_operations = {
.open = slabstats_open,
.read = seq_read,
.llseek = seq_lseek,
.release = slabstats_release,
};
#endif
#endif
static int show_stat(struct seq_file *p, void *v)
......@@ -744,6 +778,9 @@ void __init proc_misc_init(void)
create_seq_entry("interrupts", 0, &proc_interrupts_operations);
#ifdef CONFIG_SLAB
create_seq_entry("slabinfo",S_IWUSR|S_IRUGO,&proc_slabinfo_operations);
#ifdef CONFIG_DEBUG_SLAB_LEAK
create_seq_entry("slab_allocators", 0 ,&proc_slabstats_operations);
#endif
#endif
create_seq_entry("buddyinfo",S_IRUGO, &fragmentation_file_operations);
create_seq_entry("vmstat",S_IRUGO, &proc_vmstat_file_operations);
......
......@@ -77,11 +77,12 @@ struct cache_sizes {
};
extern struct cache_sizes malloc_sizes[];
#ifndef CONFIG_DEBUG_SLAB
extern void *__kmalloc(size_t, gfp_t);
#ifndef CONFIG_DEBUG_SLAB
#define ____kmalloc(size, flags) __kmalloc(size, flags)
#else
extern void *__kmalloc_track_caller(size_t, gfp_t, void*);
#define __kmalloc(size, flags) \
#define ____kmalloc(size, flags) \
__kmalloc_track_caller(size, flags, __builtin_return_address(0))
#endif
......@@ -173,6 +174,7 @@ static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
#define kmem_ptr_validate(a, b) (0)
#define kmem_cache_alloc_node(c, f, n) kmem_cache_alloc(c, f)
#define kmalloc_node(s, f, n) kmalloc(s, f)
#define ____kmalloc kmalloc
#endif /* CONFIG_SLOB */
......
......@@ -85,6 +85,10 @@ config DEBUG_SLAB
allocation as well as poisoning memory on free to catch use of freed
memory. This can make kmalloc/kfree-intensive workloads much slower.
config DEBUG_SLAB_LEAK
bool "Memory leak debugging"
depends on DEBUG_SLAB
config DEBUG_PREEMPT
bool "Debug preemptible kernel"
depends on DEBUG_KERNEL && PREEMPT
......
......@@ -204,7 +204,8 @@
typedef unsigned int kmem_bufctl_t;
#define BUFCTL_END (((kmem_bufctl_t)(~0U))-0)
#define BUFCTL_FREE (((kmem_bufctl_t)(~0U))-1)
#define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-2)
#define BUFCTL_ACTIVE (((kmem_bufctl_t)(~0U))-2)
#define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-3)
/* Max number of objs-per-slab for caches which use off-slab slabs.
* Needed to avoid a possible looping condition in cache_grow().
......@@ -2399,7 +2400,7 @@ static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
/* Verify that the slab belongs to the intended node */
WARN_ON(slabp->nodeid != nodeid);
if (slab_bufctl(slabp)[objnr] != BUFCTL_FREE) {
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();
......@@ -2605,6 +2606,9 @@ static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
*/
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)) {
......@@ -2788,6 +2792,16 @@ static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
*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;
......@@ -3220,22 +3234,23 @@ static __always_inline void *__do_kmalloc(size_t size, gfp_t flags,
return __cache_alloc(cachep, flags, caller);
}
#ifndef CONFIG_DEBUG_SLAB
void *__kmalloc(size_t size, gfp_t flags)
{
#ifndef CONFIG_DEBUG_SLAB
return __do_kmalloc(size, flags, NULL);
#else
return __do_kmalloc(size, flags, __builtin_return_address(0));
#endif
}
EXPORT_SYMBOL(__kmalloc);
#else
#ifdef CONFIG_DEBUG_SLAB
void *__kmalloc_track_caller(size_t size, gfp_t flags, void *caller)
{
return __do_kmalloc(size, flags, caller);
}
EXPORT_SYMBOL(__kmalloc_track_caller);
#endif
#ifdef CONFIG_SMP
......@@ -3899,6 +3914,159 @@ ssize_t slabinfo_write(struct file *file, const char __user * buffer,
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 list_head *q;
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(q, &l3->slabs_full) {
slabp = list_entry(q, struct slab, list);
handle_slab(n, cachep, slabp);
}
list_for_each(q, &l3->slabs_partial) {
slabp = list_entry(q, struct slab, 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;
}
struct seq_operations slabstats_op = {
.start = leaks_start,
.next = s_next,
.stop = s_stop,
.show = leaks_show,
};
#endif
#endif
/**
......
......@@ -11,7 +11,7 @@
*/
void *kzalloc(size_t size, gfp_t flags)
{
void *ret = kmalloc(size, flags);
void *ret = ____kmalloc(size, flags);
if (ret)
memset(ret, 0, size);
return ret;
......@@ -33,7 +33,7 @@ char *kstrdup(const char *s, gfp_t gfp)
return NULL;
len = strlen(s) + 1;
buf = kmalloc(len, gfp);
buf = ____kmalloc(len, gfp);
if (buf)
memcpy(buf, s, len);
return buf;
......
......@@ -149,7 +149,7 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask,
/* Get the DATA. Size must match skb_add_mtu(). */
size = SKB_DATA_ALIGN(size);
data = kmalloc(size + sizeof(struct skb_shared_info), gfp_mask);
data = ____kmalloc(size + sizeof(struct skb_shared_info), gfp_mask);
if (!data)
goto nodata;
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment