On Tue, 20 Dec 2011 18:05:03 +0800
Bob Liu <lliubbo@xxxxxxxxx> wrote:
> Current struct mem_cgroup_per_node and struct mem_cgroup_tree_per_node are
> malloced for all possible node during system boot.
>
> This may cause some memory waste, better if move it to memory hotplug.
>
> Signed-off-by: Bob Liu <lliubbo@xxxxxxxxx>
Ying Han and google people tries to remove this rb_tree completely now.
So, could you wait for a while ?
And I'm not sure how benefical this is...
Are we safe at freeing the node at OFFLINE without confirming there are no
reference ?
Thanks,
-Kame
> ---
> mm/memcontrol.c | 89 +++++++++++++++++++++++++++++++++++++++++-------------
> 1 files changed, 67 insertions(+), 22 deletions(-)
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index a3d0420..a7a906b 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -570,7 +570,7 @@ static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg)
> struct mem_cgroup_per_zone *mz;
> struct mem_cgroup_tree_per_zone *mctz;
>
> - for_each_node(node) {
> + for_each_node_state(nid, N_NORMAL_MEMORY) {
> for (zone = 0; zone < MAX_NR_ZONES; zone++) {
> mz = mem_cgroup_zoneinfo(memcg, node, zone);
> mctz = soft_limit_tree_node_zone(node, zone);
> @@ -4894,18 +4894,9 @@ static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node)
> struct mem_cgroup_per_node *pn;
> struct mem_cgroup_per_zone *mz;
> enum lru_list l;
> - int zone, tmp = node;
> - /*
> - * This routine is called against possible nodes.
> - * But it's BUG to call kmalloc() against offline node.
> - *
> - * TODO: this routine can waste much memory for nodes which will
> - * never be onlined. It's better to use memory hotplug callback
> - * function.
> - */
> - if (!node_state(node, N_NORMAL_MEMORY))
> - tmp = -1;
> - pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp);
> + int zone;
> +
> + pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, node);
> if (!pn)
> return 1;
>
> @@ -4972,7 +4963,7 @@ static void __mem_cgroup_free(struct mem_cgroup *memcg)
> mem_cgroup_remove_from_trees(memcg);
> free_css_id(&mem_cgroup_subsys, &memcg->css);
>
> - for_each_node(node)
> + for_each_node_state(nid, N_NORMAL_MEMORY)
> free_mem_cgroup_per_zone_info(memcg, node);
>
> free_percpu(memcg->stat);
> @@ -5025,17 +5016,70 @@ static void __init enable_swap_cgroup(void)
> }
> #endif
>
> +#ifdef CONFIG_MEMORY_HOTPLUG
> +static int __meminit memcg_mem_hotplug_callback(struct notifier_block *self,
> + unsigned long action, void *arg)
> +{
> + struct memory_notify *mn = arg;
> + struct mem_cgroup *iter;
> + struct mem_cgroup_tree_per_node *rtpn;
> + struct mem_cgroup_tree_per_zone *rtpz;
> + int ret = 0;
> + int nid = mn->status_change_nid;
> + int zone;
> +
> + switch (action) {
> + case MEM_ONLINE:
> + if (nid != -1) {
> + for_each_mem_cgroup(iter){
> + ret = alloc_mem_cgroup_per_zone_info(iter, nid);
> + if (ret)
> + goto free_out;
> + }
> +
> + rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, nid);
> + if (!rtpn)
> + goto free_out;
> +
> + soft_limit_tree.rb_tree_per_node[nid] = rtpn;
> +
> + for (zone = 0; zone < MAX_NR_ZONES; zone++) {
> + rtpz = &rtpn->rb_tree_per_zone[zone];
> + rtpz->rb_root = RB_ROOT;
> + spin_lock_init(&rtpz->lock);
> + }
> + }
> + break;
> + case MEM_OFFLINE:
> + if (nid != -1) {
> + rtpn = soft_limit_tree.rb_tree_per_node[nid];
> + if (rtpn) {
> + kfree(rtpn);
> + soft_limit_tree.rb_tree_per_node[nid] = NULL;
> + }
> + goto free_out;
> + }
> + break;
> + }
> +
> +out:
> + return notifier_from_errno(ret);
> +
> +free_out:
> + for_each_mem_cgroup(iter)
> + free_mem_cgroup_per_zone_info(iter, nid);
> + goto out;
> +}
> +#endif
> +
> static int mem_cgroup_soft_limit_tree_init(void)
> {
> struct mem_cgroup_tree_per_node *rtpn;
> struct mem_cgroup_tree_per_zone *rtpz;
> - int tmp, node, zone;
> + int node, zone;
>
> - for_each_node(node) {
> - tmp = node;
> - if (!node_state(node, N_NORMAL_MEMORY))
> - tmp = -1;
> - rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp);
> + for_each_node_state(nid, N_NORMAL_MEMORY) {
> + rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, node);
> if (!rtpn)
> goto err_cleanup;
>
> @@ -5050,7 +5094,7 @@ static int mem_cgroup_soft_limit_tree_init(void)
> return 0;
>
> err_cleanup:
> - for_each_node(node) {
> + for_each_node_state(nid, N_NORMAL_MEMORY) {
> if (!soft_limit_tree.rb_tree_per_node[node])
> break;
> kfree(soft_limit_tree.rb_tree_per_node[node]);
> @@ -5071,7 +5115,7 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
> if (!memcg)
> return ERR_PTR(error);
>
> - for_each_node(node)
> + for_each_node_state(nid, N_NORMAL_MEMORY)
> if (alloc_mem_cgroup_per_zone_info(memcg, node))
> goto free_out;
>
> @@ -5119,6 +5163,7 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
> atomic_set(&memcg->refcnt, 1);
> memcg->move_charge_at_immigrate = 0;
> mutex_init(&memcg->thresholds_lock);
> + hotplug_memory_notifier(memcg_mem_hotplug_callback, 0);
> return &memcg->css;
> free_out:
> __mem_cgroup_free(memcg);
> --
> 1.7.0.4
>
>
>
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