[patch] slub: provide /proc/slabinfo

Ingo Molnar
2008-01-01T16:24:17Z

* Theodore Tso <tytso@MIT.EDU> wrote:

> [...] doesn't a patch to provide /proc/slabinfo for SLUB already
> exist?

yes, the complete (and tested) patch is below. It has been through a few
thousand random-bootup tests on x86 32-bit and 64-bit so it's v2.6.24
material i think.

Ingo

----------------->
Subject: slub: provide /proc/slabinfo
From: Pekka J Enberg <penberg@cs.helsinki.fi>

This adds a read-only /proc/slabinfo file on SLUB, that makes slabtop work.

[ mingo@elte.hu: build fix. ]

Cc: Andi Kleen <andi@firstfloor.org>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
include/linux/slub_def.h | 2
mm/slub.c | 105 +++++++++++++++++++++++++++++++++++++++++------
2 files changed, 94 insertions(+), 13 deletions(-)

Index: linux/include/linux/slub_def.h
===================================================================
--- linux.orig/include/linux/slub_def.h
+++ linux/include/linux/slub_def.h
@@ -200,4 +200,6 @@ static __always_inline void *kmalloc_nod
}
#endif

+extern const struct seq_operations slabinfo_op;
+
#endif /* _LINUX_SLUB_DEF_H */
Index: linux/mm/slub.c
===================================================================
--- linux.orig/mm/slub.c
+++ linux/mm/slub.c
@@ -3076,6 +3076,19 @@ void *__kmalloc_node_track_caller(size_t
return slab_alloc(s, gfpflags, node, caller);
}

+static unsigned long count_partial(struct kmem_cache_node *n)
+{
+ unsigned long flags;
+ unsigned long x = 0;
+ struct page *page;
+
+ spin_lock_irqsave(&n->list_lock, flags);
+ list_for_each_entry(page, &n->partial, lru)
+ x += page->inuse;
+ spin_unlock_irqrestore(&n->list_lock, flags);
+ return x;
+}
+
#if defined(CONFIG_SYSFS) && defined(CONFIG_SLUB_DEBUG)
static int validate_slab(struct kmem_cache *s, struct page *page,
unsigned long *map)
@@ -3458,19 +3471,6 @@ static int list_locations(struct kmem_ca
return n;
}

-static unsigned long count_partial(struct kmem_cache_node *n)
-{
- unsigned long flags;
- unsigned long x = 0;
- struct page *page;
-
- spin_lock_irqsave(&n->list_lock, flags);
- list_for_each_entry(page, &n->partial, lru)
- x += page->inuse;
- spin_unlock_irqrestore(&n->list_lock, flags);
- return x;
-}
-
enum slab_stat_type {
SL_FULL,
SL_PARTIAL,
@@ -4123,3 +4123,82 @@ static int __init slab_sysfs_init(void)

__initcall(slab_sysfs_init);
#endif
+
+/*
+ * The /proc/slabinfo ABI
+ */
+#ifdef CONFIG_PROC_FS
+
+static void print_slabinfo_header(struct seq_file *m)
+{
+ seq_puts(m, "slabinfo - version: 2.1\n");
+ 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>");
+ seq_putc(m, '\n');
+}
+
+static void *s_start(struct seq_file *m, loff_t *pos)
+{
+ loff_t n = *pos;
+
+ down_read(&slub_lock);
+ 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)
+{
+ up_read(&slub_lock);
+}
+
+static int s_show(struct seq_file *m, void *p)
+{
+ unsigned long nr_partials = 0;
+ unsigned long nr_slabs = 0;
+ unsigned long nr_inuse = 0;
+ unsigned long nr_objs;
+ struct kmem_cache *s;
+ int node;
+
+ s = list_entry(p, struct kmem_cache, list);
+
+ for_each_online_node(node) {
+ struct kmem_cache_node *n = get_node(s, node);
+
+ if (!n)
+ continue;
+
+ nr_partials += n->nr_partial;
+ nr_slabs += atomic_long_read(&n->nr_slabs);
+ nr_inuse += count_partial(n);
+ }
+
+ nr_objs = nr_slabs * s->objects;
+ nr_inuse += (nr_slabs - nr_partials) * s->objects;
+
+ seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", s->name, nr_inuse,
+ nr_objs, s->size, s->objects, (1 << s->order));
+ seq_printf(m, " : tunables %4u %4u %4u", 0, 0, 0);
+ seq_printf(m, " : slabdata %6lu %6lu %6lu", nr_slabs, nr_slabs,
+ 0UL);
+ seq_putc(m, '\n');
+ return 0;
+}
+
+const struct seq_operations slabinfo_op = {
+ .start = s_start,
+ .next = s_next,
+ .stop = s_stop,
+ .show = s_show,
+};
+
+#endif /* CONFIG_PROC_FS */