mm/sl[au]b: Move slabinfo processing to slab_common.c

This patch moves all the common machinery to slabinfo processing
to slab_common.c. We can do better by noticing that the output is
heavily common, and having the allocators to just provide finished
information about this. But after this first step, this can be done
easier.

Signed-off-by: Glauber Costa <glommer@parallels.com>
Acked-by: Christoph Lameter <cl@linux.com>
CC: David Rientjes <rientjes@google.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

1 files changed, 70 insertions, 0 deletions

diff --git a/mm/slab_common.c b/mm/slab_common.c
index 069a24e64403..2e4b4c6d89e2 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -13,6 +13,8 @@
 #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>
@@ -192,3 +194,71 @@ int slab_is_available(void)
 {
         return slab_state >= UP;
 }
+
+#ifdef CONFIG_SLABINFO
+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 int s_show(struct seq_file *m, void *p)
+{
+        return slabinfo_show(m, p);
+}
+
+/*
+ * 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 */