Re: [patch 2/3] mm: memcontrol: consolidate memory controller initialization

[Vladimir Davydov <vdavydov@parallels.com>]

On Fri, Jan 09, 2015 at 09:14:00PM -0500, Johannes Weiner wrote:
> The initialization code for the per-cpu charge stock and the soft
> limit tree is compact enough to inline it into mem_cgroup_init().
> 
> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
> ---
>  mm/memcontrol.c | 57 ++++++++++++++++++++++++---------------------------------
>  1 file changed, 24 insertions(+), 33 deletions(-)
> 
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index aad254b30708..f66bb8f83ac9 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
[...]
> @@ -5927,10 +5896,32 @@ void mem_cgroup_migrate(struct page *oldpage, struct page *newpage,
>   */
>  static int __init mem_cgroup_init(void)
>  {
> +	int cpu, nid;
> +
>  	hotcpu_notifier(memcg_cpu_hotplug_callback, 0);
> +
> +	for_each_possible_cpu(cpu)
> +		INIT_WORK(&per_cpu_ptr(&memcg_stock, cpu)->work,
> +			  drain_local_stock);
> +
> +	for_each_node(nid) {
> +		struct mem_cgroup_tree_per_node *rtpn;
> +		int zone;
> +
> +		rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, nid);

I'd like to see BUG_ON(!rtpn) here, just for clarity. Not critical
though.

Reviewed-by: Vladimir Davydov <vdavydov@parallels.com>

> +
> +		for (zone = 0; zone < MAX_NR_ZONES; zone++) {
> +			struct mem_cgroup_tree_per_zone *rtpz;
> +
> +			rtpz = &rtpn->rb_tree_per_zone[zone];
> +			rtpz->rb_root = RB_ROOT;
> +			spin_lock_init(&rtpz->lock);
> +		}
> +		soft_limit_tree.rb_tree_per_node[nid] = rtpn;
> +	}
> +
>  	enable_swap_cgroup();
> -	mem_cgroup_soft_limit_tree_init();
> -	memcg_stock_init();
> +
>  	return 0;
>  }
>  subsys_initcall(mem_cgroup_init);
> -- 
> 2.2.0
>