(2012/11/15 11:54), Glauber Costa wrote:
> The idea is to synchronously do it, leaving it up to the shrinking
> facilities in vmscan.c and/or others. Not actively retrying shrinking
> may leave the caches alive for more time, but it will remove the ugly
> wakeups. One would argue that if the caches have free objects but are
> not being shrunk, it is because we don't need that memory yet.
>
> Signed-off-by: Glauber Costa <glommer@xxxxxxxxxxxxx>
> CC: Michal Hocko <mhocko@xxxxxxx>
> CC: Kamezawa Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
> CC: Johannes Weiner <hannes@xxxxxxxxxxx>
> CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
I agree this patch but can we have a way to see the number of unaccounted
zombie cache usage for debugging ?
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
> ---
> include/linux/slab.h | 2 +-
> mm/memcontrol.c | 17 +++++++----------
> 2 files changed, 8 insertions(+), 11 deletions(-)
>
> diff --git a/include/linux/slab.h b/include/linux/slab.h
> index 18f8c98..456c327 100644
> --- a/include/linux/slab.h
> +++ b/include/linux/slab.h
> @@ -214,7 +214,7 @@ struct memcg_cache_params {
> struct kmem_cache *root_cache;
> bool dead;
> atomic_t nr_pages;
> - struct delayed_work destroy;
> + struct work_struct destroy;
> };
> };
> };
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index f9c5981..e3d805f 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -3077,9 +3077,8 @@ static void kmem_cache_destroy_work_func(struct work_struct *w)
> {
> struct kmem_cache *cachep;
> struct memcg_cache_params *p;
> - struct delayed_work *dw = to_delayed_work(w);
>
> - p = container_of(dw, struct memcg_cache_params, destroy);
> + p = container_of(w, struct memcg_cache_params, destroy);
>
> cachep = memcg_params_to_cache(p);
>
> @@ -3103,8 +3102,6 @@ static void kmem_cache_destroy_work_func(struct work_struct *w)
> kmem_cache_shrink(cachep);
> if (atomic_read(&cachep->memcg_params->nr_pages) == 0)
> return;
> - /* Once per minute should be good enough. */
> - schedule_delayed_work(&cachep->memcg_params->destroy, 60 * HZ);
> } else
> kmem_cache_destroy(cachep);
> }
> @@ -3127,18 +3124,18 @@ void mem_cgroup_destroy_cache(struct kmem_cache *cachep)
> * kmem_cache_shrink is enough to shake all the remaining objects and
> * get the page count to 0. In this case, we'll deadlock if we try to
> * cancel the work (the worker runs with an internal lock held, which
> - * is the same lock we would hold for cancel_delayed_work_sync().)
> + * is the same lock we would hold for cancel_work_sync().)
> *
> * Since we can't possibly know who got us here, just refrain from
> * running if there is already work pending
> */
> - if (delayed_work_pending(&cachep->memcg_params->destroy))
> + if (work_pending(&cachep->memcg_params->destroy))
> return;
> /*
> * We have to defer the actual destroying to a workqueue, because
> * we might currently be in a context that cannot sleep.
> */
> - schedule_delayed_work(&cachep->memcg_params->destroy, 0);
> + schedule_work(&cachep->memcg_params->destroy);
> }
>
> static char *memcg_cache_name(struct mem_cgroup *memcg, struct kmem_cache *s)
> @@ -3261,7 +3258,7 @@ void kmem_cache_destroy_memcg_children(struct kmem_cache *s)
> * set, so flip it down to guarantee we are in control.
> */
> c->memcg_params->dead = false;
> - cancel_delayed_work_sync(&c->memcg_params->destroy);
> + cancel_work_sync(&c->memcg_params->destroy);
> kmem_cache_destroy(c);
> }
> mutex_unlock(&set_limit_mutex);
> @@ -3285,9 +3282,9 @@ static void mem_cgroup_destroy_all_caches(struct mem_cgroup *memcg)
> list_for_each_entry(params, &memcg->memcg_slab_caches, list) {
> cachep = memcg_params_to_cache(params);
> cachep->memcg_params->dead = true;
> - INIT_DELAYED_WORK(&cachep->memcg_params->destroy,
> + INIT_WORK(&cachep->memcg_params->destroy,
> kmem_cache_destroy_work_func);
> - schedule_delayed_work(&cachep->memcg_params->destroy, 0);
> + schedule_work(&cachep->memcg_params->destroy);
> }
> mutex_unlock(&memcg->slab_caches_mutex);
> }
>
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>