Re: [PATCH v2 12/13] memcg: Per-memcg memory.kmem.slabinfo file.

[Glauber Costa]

On 03/10/2012 12:39 AM, Suleiman Souhlal wrote:
> This file shows all the kmem_caches used by a memcg.
>
> Signed-off-by: Suleiman Souhlal<suleiman@xxxxxxxxxx>
Reviewed-by: Glauber Costa <glommer@xxxxxxxxxxxxx>

> ---
>   include/linux/slab.h     |    6 +++
>   include/linux/slab_def.h |    1 +
>   mm/memcontrol.c          |   18 +++++++++
>   mm/slab.c                |   88 ++++++++++++++++++++++++++++++++++------------
>   4 files changed, 90 insertions(+), 23 deletions(-)
>
> diff --git a/include/linux/slab.h b/include/linux/slab.h
> index fd1d2ba..0ff5ee2 100644
> --- a/include/linux/slab.h
> +++ b/include/linux/slab.h
> @@ -401,6 +401,12 @@ static inline void *kmalloc_no_account(size_t size, gfp_t flags)
>   	return kmalloc(size, flags);
>   }
>
> +static inline int
> +mem_cgroup_slabinfo(struct mem_cgroup *mem, struct seq_file *m)
> +{
> +	return 0;
> +}
> +
>   #endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM&&  CONFIG_SLAB */
>
>   #endif	/* _LINUX_SLAB_H */
> diff --git a/include/linux/slab_def.h b/include/linux/slab_def.h
> index 248b8a9..fa6b272 100644
> --- a/include/linux/slab_def.h
> +++ b/include/linux/slab_def.h
> @@ -227,6 +227,7 @@ found:
>   #ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
>
>   void kmem_cache_drop_ref(struct kmem_cache *cachep);
> +int mem_cgroup_slabinfo(struct mem_cgroup *mem, struct seq_file *m);
>
>   static inline void
>   kmem_cache_get_ref(struct kmem_cache *cachep)
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 9f5e9d8..4a4fa48 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -4672,6 +4672,20 @@ static int mem_cgroup_independent_kmem_limit_write(struct cgroup *cgrp,
>   	return 0;
>   }
>
> +static int
> +mem_cgroup_slabinfo_show(struct cgroup *cgroup, struct cftype *ctf,
> +    struct seq_file *m)
> +{
> +	struct mem_cgroup *mem;
> +
> +	mem  = mem_cgroup_from_cont(cgroup);
> +
> +	if (mem == root_mem_cgroup)
> +		mem = NULL;
> +
> +	return mem_cgroup_slabinfo(mem, m);
> +}
> +
>   static struct cftype kmem_cgroup_files[] = {
>   	{
>   		.name = "kmem.independent_kmem_limit",
> @@ -4689,6 +4703,10 @@ static struct cftype kmem_cgroup_files[] = {
>   		.private = MEMFILE_PRIVATE(_KMEM, RES_USAGE),
>   		.read_u64 = mem_cgroup_read,
>   	},
> +	{
> +		.name = "kmem.slabinfo",
> +		.read_seq_string = mem_cgroup_slabinfo_show,
> +	},
>   };
>
>   static int register_kmem_files(struct cgroup *cont, struct cgroup_subsys *ss)
> diff --git a/mm/slab.c b/mm/slab.c
> index 02239ed..1b35799 100644
> --- a/mm/slab.c
> +++ b/mm/slab.c
> @@ -4528,21 +4528,26 @@ static void s_stop(struct seq_file *m, void *p)
>   	mutex_unlock(&cache_chain_mutex);
>   }
>
> -static int s_show(struct seq_file *m, void *p)
> -{
> -	struct kmem_cache *cachep = list_entry(p, struct kmem_cache, next);
> -	struct slab *slabp;
> +struct slab_counts {
>   	unsigned long active_objs;
> +	unsigned long active_slabs;
> +	unsigned long num_slabs;
> +	unsigned long free_objects;
> +	unsigned long shared_avail;
>   	unsigned long num_objs;
> -	unsigned long active_slabs = 0;
> -	unsigned long num_slabs, free_objects = 0, shared_avail = 0;
> -	const char *name;
> -	char *error = NULL;
> -	int node;
> +};
> +
> +static char *
> +get_slab_counts(struct kmem_cache *cachep, struct slab_counts *c)
> +{
>   	struct kmem_list3 *l3;
> +	struct slab *slabp;
> +	char *error;
> +	int node;
> +
> +	error = NULL;
> +	memset(c, 0, sizeof(struct slab_counts));
>
> -	active_objs = 0;
> -	num_slabs = 0;
>   	for_each_online_node(node) {
>   		l3 = cachep->nodelists[node];
>   		if (!l3)
> @@ -4554,31 +4559,43 @@ static int s_show(struct seq_file *m, void *p)
>   		list_for_each_entry(slabp,&l3->slabs_full, list) {
>   			if (slabp->inuse != cachep->num&&  !error)
>   				error = "slabs_full accounting error";
> -			active_objs += cachep->num;
> -			active_slabs++;
> +			c->active_objs += cachep->num;
> +			c->active_slabs++;
>   		}
>   		list_for_each_entry(slabp,&l3->slabs_partial, list) {
>   			if (slabp->inuse == cachep->num&&  !error)
>   				error = "slabs_partial inuse accounting error";
>   			if (!slabp->inuse&&  !error)
>   				error = "slabs_partial/inuse accounting error";
> -			active_objs += slabp->inuse;
> -			active_slabs++;
> +			c->active_objs += slabp->inuse;
> +			c->active_slabs++;
>   		}
>   		list_for_each_entry(slabp,&l3->slabs_free, list) {
>   			if (slabp->inuse&&  !error)
>   				error = "slabs_free/inuse accounting error";
> -			num_slabs++;
> +			c->num_slabs++;
>   		}
> -		free_objects += l3->free_objects;
> +		c->free_objects += l3->free_objects;
>   		if (l3->shared)
> -			shared_avail += l3->shared->avail;
> +			c->shared_avail += l3->shared->avail;
>
>   		spin_unlock_irq(&l3->list_lock);
>   	}
> -	num_slabs += active_slabs;
> -	num_objs = num_slabs * cachep->num;
> -	if (num_objs - active_objs != free_objects&&  !error)
> +	c->num_slabs += c->active_slabs;
> +	c->num_objs = c->num_slabs * cachep->num;
> +
> +	return error;
> +}
> +
> +static int s_show(struct seq_file *m, void *p)
> +{
> +	struct kmem_cache *cachep = list_entry(p, struct kmem_cache, next);
> +	struct slab_counts c;
> +	const char *name;
> +	char *error;
> +
> +	error = get_slab_counts(cachep,&c);
> +	if (c.num_objs - c.active_objs != c.free_objects&&  !error)
>   		error = "free_objects accounting error";
>
>   	name = cachep->name;
> @@ -4586,12 +4603,12 @@ static int s_show(struct seq_file *m, void *p)
>   		printk(KERN_ERR "slab: cache %s error: %s\n", name, error);
>
>   	seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
> -		   name, active_objs, num_objs, cachep->buffer_size,
> +		   name, c.active_objs, c.num_objs, cachep->buffer_size,
>   		   cachep->num, (1<<  cachep->gfporder));
>   	seq_printf(m, " : tunables %4u %4u %4u",
>   		   cachep->limit, cachep->batchcount, cachep->shared);
>   	seq_printf(m, " : slabdata %6lu %6lu %6lu",
> -		   active_slabs, num_slabs, shared_avail);
> +		   c.active_slabs, c.num_slabs, c.shared_avail);
>   #if STATS
>   	{			/* list3 stats */
>   		unsigned long high = cachep->high_mark;
> @@ -4726,6 +4743,31 @@ static const struct file_operations proc_slabinfo_operations = {
>   	.release	= seq_release,
>   };
>
> +#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
> +int
> +mem_cgroup_slabinfo(struct mem_cgroup *mem, struct seq_file *m)
> +{
> +	struct kmem_cache *cachep;
> +	struct slab_counts c;
> +
> +	seq_printf(m, "# name<active_objs>  <num_objs>  <objsize>\n");
> +
> +	mutex_lock(&cache_chain_mutex);
> +	list_for_each_entry(cachep,&cache_chain, next) {
> +		if (cachep->memcg_params.memcg != mem)
> +			continue;
> +
> +		get_slab_counts(cachep,&c);
> +
> +		seq_printf(m, "%-17s %6lu %6lu %6u\n", cachep->name,
> +		   c.active_objs, c.num_objs, cachep->buffer_size);
> +	}
> +	mutex_unlock(&cache_chain_mutex);
> +
> +	return 0;
> +}
> +#endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
> +
>   #ifdef CONFIG_DEBUG_SLAB_LEAK
>
>   static void *leaks_start(struct seq_file *m, loff_t *pos)

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/