Provide some more detail on what is going on with various types of object
in slabs. This is mainly useful for debugging the queueing operations.
Signed-off-by: Christoph Lameter <cl@xxxxxxxxx>
---
mm/slub.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++++---------
1 file changed, 74 insertions(+), 12 deletions(-)
Index: linux-2.6/mm/slub.c
===================================================================
--- linux-2.6.orig/mm/slub.c 2010-10-05 13:40:08.000000000 -0500
+++ linux-2.6/mm/slub.c 2010-10-05 13:40:11.000000000 -0500
@@ -4151,12 +4151,24 @@ static int count_total(struct page *page
#endif
#ifdef CONFIG_SLUB_DEBUG
-static int validate_slab(struct kmem_cache *s, struct page *page)
+
+struct validate_counters {
+ int objects;
+ int available;
+ int queue;
+ int checked;
+ int unchecked;
+ int hist[];
+};
+
+static int validate_slab(struct kmem_cache *s, struct page *page,
+ int partial, struct validate_counters *v)
{
void *p;
void *addr = page_address(page);
unsigned long *m = map(page);
unsigned long errors = 0;
+ unsigned long inuse = 0;
if (!check_slab(s, page) || !verify_slab(s, page))
return 0;
@@ -4168,7 +4180,10 @@ static int validate_slab(struct kmem_cac
/* Available */
if (!check_object(s, page, p, SLUB_RED_INACTIVE))
errors++;
+ else
+ v->available++;
} else {
+ inuse++;
#ifdef CONFIG_SLUB_DEBUG
/*
* We cannot check if the object is on a queue without
@@ -4178,24 +4193,45 @@ static int validate_slab(struct kmem_cac
if (s->flags & SLAB_RED_ZONE) {
u8 *q = p + s->objsize;
- if (*q != SLUB_RED_QUEUE)
+ if (*q != SLUB_RED_QUEUE) {
if (!check_object(s, page, p, SLUB_RED_ACTIVE))
errors++;
- }
+ else
+ v->checked++;
+ } else
+ v->queue++;
+ } else
+ /*
+ * Allocated object that cannot be verified
+ * since red zoning is diabled. The object
+ * may be free after all if its on a queue.
+ */
#endif
+ v->unchecked++;
}
}
+ v->hist[inuse]++;
+
+ if (inuse < page->objects) {
+ if (!partial)
+ slab_err(s, page, "Objects available but not on partial list");
+ } else {
+ if (partial)
+ slab_err(s, page, "On partial list but no object available");
+ }
+ v->objects += page->objects;
return errors;
}
-static unsigned long validate_slab_slab(struct kmem_cache *s, struct page *page)
+static unsigned long validate_slab_slab(struct kmem_cache *s,
+ struct page *page, int partial, struct validate_counters *v)
{
- return validate_slab(s, page);
+ return validate_slab(s, page, partial, v);
}
static int validate_slab_node(struct kmem_cache *s,
- struct kmem_cache_node *n)
+ struct kmem_cache_node *n, struct validate_counters *v)
{
unsigned long count = 0;
struct page *page;
@@ -4206,7 +4242,7 @@ static int validate_slab_node(struct kme
list_for_each_entry(page, &n->partial, lru) {
if (get_node(s, page_to_nid(page)) == n)
- errors += validate_slab_slab(s, page);
+ errors += validate_slab_slab(s, page, 1, v);
else
printk(KERN_ERR "SLUB %s: Partial list page from wrong node\n", s->name);
count++;
@@ -4219,7 +4255,7 @@ static int validate_slab_node(struct kme
goto out;
list_for_each_entry(page, &n->full, lru) {
- validate_slab_slab(s, page);
+ errors += validate_slab_slab(s, page, 0, v);
count++;
}
if (count != atomic_long_read(&n->nr_slabs))
@@ -4235,15 +4271,41 @@ out:
static long validate_slab_cache(struct kmem_cache *s)
{
int node;
- unsigned long count = 0;
+ int i;
+ struct validate_counters *v;
+ unsigned long errors = 0;
+ int maxobj = oo_objects(s->max);
+
+ v = kzalloc(GFP_KERNEL, offsetof(struct validate_counters, hist) + maxobj * sizeof(int));
+ if (!v)
+ return -ENOMEM;
- flush_all(s);
for_each_node_state(node, N_NORMAL_MEMORY) {
struct kmem_cache_node *n = get_node(s, node);
- count += validate_slab_node(s, n);
+ errors += validate_slab_node(s, n, v);
}
- return count;
+
+ printk(KERN_DEBUG "Validation of slab %s: total=%d available=%d checked=%d",
+ s->name, v->objects, v->available, v->checked);
+
+ if (v->unchecked)
+ printk(" unchecked=%d", v->unchecked);
+
+ if (v->queue)
+ printk(" onqueue=%d", v->queue);
+
+ if (errors)
+ printk(" errors=%lu", errors);
+
+ for (i = 0; i < maxobj; i++)
+ if (v->hist[i])
+ printk(" p<%d>=%d", i, v->hist[i]);
+
+ printk("\n");
+ kfree(v);
+
+ return errors;
}
/*
* Generate lists of code addresses where slabcache objects are allocated
--
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