[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: Al 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: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/proc/proc_misc.c b/fs/proc/proc_misc.c
index 826c131..1e9ea37 100644
--- a/fs/proc/proc_misc.c
+++ b/fs/proc/proc_misc.c
@@ -485,6 +485,40 @@
 	.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 @@
 	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);