Re: [PATCH v5 09/14] memcg: kmem accounting lifecycle management

From: David Rientjes
Date: Wed Oct 17 2012 - 19:28:31 EST


On Tue, 16 Oct 2012, Glauber Costa wrote:

> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 1182188..e24b388 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -344,6 +344,7 @@ struct mem_cgroup {
> /* internal only representation about the status of kmem accounting. */
> enum {
> KMEM_ACCOUNTED_ACTIVE = 0, /* accounted by this cgroup itself */
> + KMEM_ACCOUNTED_DEAD, /* dead memcg, pending kmem charges */

"dead memcg with pending kmem charges" seems better.

> };
>
> #define KMEM_ACCOUNTED_MASK (1 << KMEM_ACCOUNTED_ACTIVE)
> @@ -353,6 +354,22 @@ static void memcg_kmem_set_active(struct mem_cgroup *memcg)
> {
> set_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_accounted);
> }
> +
> +static bool memcg_kmem_is_active(struct mem_cgroup *memcg)
> +{
> + return test_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_accounted);
> +}

I think all of these should be inline.

> +
> +static void memcg_kmem_mark_dead(struct mem_cgroup *memcg)
> +{
> + if (test_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_accounted))
> + set_bit(KMEM_ACCOUNTED_DEAD, &memcg->kmem_accounted);
> +}

The set_bit() doesn't happen atomically with the test_bit(), what
synchronization is required for this?
--
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/