[Devel] Re: [PATCH v3 11/16] memcg: destroy memcg caches

[Tejun Heo]

Hello, Glauber.

On Tue, Sep 18, 2012 at 06:12:05PM +0400, Glauber Costa wrote:
> +static LIST_HEAD(destroyed_caches);
> +
> +static void kmem_cache_destroy_work_func(struct work_struct *w)
> +{
> +	struct kmem_cache *cachep;
> +	struct mem_cgroup_cache_params *p, *tmp;
> +	unsigned long flags;
> +	LIST_HEAD(del_unlocked);
> +
> +	spin_lock_irqsave(&cache_queue_lock, flags);
> +	list_for_each_entry_safe(p, tmp, &destroyed_caches, destroyed_list) {
> +		cachep = container_of(p, struct kmem_cache, memcg_params);
> +		list_move(&cachep->memcg_params.destroyed_list, &del_unlocked);
> +	}
> +	spin_unlock_irqrestore(&cache_queue_lock, flags);
> +
> +	list_for_each_entry_safe(p, tmp, &del_unlocked, destroyed_list) {
> +		cachep = container_of(p, struct kmem_cache, memcg_params);
> +		list_del(&cachep->memcg_params.destroyed_list);
> +		if (!atomic_read(&cachep->memcg_params.nr_pages)) {
> +			mem_cgroup_put(cachep->memcg_params.memcg);
> +			kmem_cache_destroy(cachep);
> +		}
> +	}
> +}
> +static DECLARE_WORK(kmem_cache_destroy_work, kmem_cache_destroy_work_func);

Again, please don't build your own worklist.  Just embed a work item
into mem_cgroup_cache_params and manipulate them.  No need to
duplicate what workqueue already implements.

Thanks.

-- 
tejun