On 05/29/2012 06:27 PM, Christoph Lameter wrote:

On Fri, 25 May 2012, Glauber Costa wrote:

quoted

index 06e4a3e..7c0cdd6 100644

--- a/include/linux/slab_def.h
+++ b/include/linux/slab_def.h

@@ -102,6 +102,13 @@ struct kmem_cache {
  	 */
  };

+static inline void store_orig_align(struct kmem_cache *cachep, int orig_align)
+{
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+	cachep->memcg_params.orig_align = orig_align;
+#endif
+}
+

Why do you need to store the original alignment? Is the calculated
alignment not enough?

I think this one can go. You are right.

quoted

+++ b/mm/slab.c

@@ -1729,6 +1729,31 @@ void __init kmem_cache_init_late(void)
  	 */
  }

+static int __init memcg_slab_register_all(void)
+{
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+	struct kmem_cache *cachep;
+	struct cache_sizes *sizes;
+
+	sizes = malloc_sizes;
+
+	while (sizes->cs_size != ULONG_MAX) {
+		if (sizes->cs_cachep)
+			mem_cgroup_register_cache(NULL, sizes->cs_cachep);
+		if (sizes->cs_dmacachep)
+			mem_cgroup_register_cache(NULL, sizes->cs_dmacachep);
+		sizes++;
+	}
+
+	mutex_lock(&cache_chain_mutex);
+	list_for_each_entry(cachep,&cache_chain, next)
+		mem_cgroup_register_cache(NULL, cachep);
+
+	mutex_unlock(&cache_chain_mutex);
+#endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
+	return 0;
+}

Ok this only duplicates the kmalloc arrays. Why not the others?

It does duplicate the others.

First it does a while look on the kmalloc caches, then a 
list_for_each_entry in the rest. You probably missed it.

quoted

@@ -2331,7 +2350,7 @@ kmem_cache_create (const char *name, size_t size, size_t align,
  			continue;
  		}

-		if (!strcmp(pc->name, name)) {
+		if (!memcg&&  !strcmp(pc->name, name)) {
  			printk(KERN_ERR
  			       "kmem_cache_create: duplicate cache %s\n", name);
  			dump_stack();

This implementation means that duplicate cache detection will no longer
work within a cgroup?

For the slab, yes. For the slub, I check to see if they belong to the 
same memcg.

That said, this can and should be fixed here too, thanks for spotting.

quoted

@@ -2543,7 +2564,12 @@ kmem_cache_create (const char *name, size_t size, size_t align,
  	cachep->ctor = ctor;
  	cachep->name = name;

+	if (g_cpucache_up>= FULL)
+		mem_cgroup_register_cache(memcg, cachep);

What happens if a cgroup was active during creation of slab xxy but
then a process running in a different cgroup uses that slab to allocate
memory? Is it charged to the first cgroup?

I don't see this situation ever happening. kmem_cache_create, when 
called directly, will always create a global cache. It doesn't matter 
which cgroups are or aren't active at this time or any other. We create 
copies per-cgroup, but we create it lazily, when someone will touch it.

At that point, which cache will be used depend on which process is using 
it.