On Fri, 1 Jun 2018 14:53:18 +0200
<osalvador@xxxxxxxxxxxxxxxxxx> wrote:
> From: Oscar Salvador <osalvador@xxxxxxx>
>
> add_memory_resource() contains code to allocate a new node in case
> it is necessary.
> Since try_online_node() also hast some code for this purpose,
> let us make use of that and remove duplicate code.
>
> This introduces __try_online_node(), which is called by add_memory_resource()
> and try_online_node().
> __try_online_node() has two new parameters, start_addr of the node,
> and if the node should be onlined and registered right away.
> This is always wanted if we are calling from do_cpu_up(), but not
> when we are calling from memhotplug code.
> Nothing changes from the point of view of the users of try_online_node(),
> since try_online_node passes start_addr=0 and online_node=true to
> __try_online_node().
>
Trivial whitespace issue inline...
> Signed-off-by: Oscar Salvador <osalvador@xxxxxxx>
> ---
> mm/memory_hotplug.c | 61 +++++++++++++++++++++++++++++------------------------
> 1 file changed, 34 insertions(+), 27 deletions(-)
>
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 7deb49f69e27..29a5fc89bdb1 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -1034,8 +1034,10 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
> return pgdat;
> }
>
> -static void rollback_node_hotadd(int nid, pg_data_t *pgdat)
> +static void rollback_node_hotadd(int nid)
> {
> + pg_data_t *pgdat = NODE_DATA(nid);
> +
> arch_refresh_nodedata(nid, NULL);
> free_percpu(pgdat->per_cpu_nodestats);
> arch_free_nodedata(pgdat);
> @@ -1046,28 +1048,43 @@ static void rollback_node_hotadd(int nid, pg_data_t *pgdat)
> /**
> * try_online_node - online a node if offlined
> * @nid: the node ID
> - *
> + * @start: start addr of the node
> + * @set_node_online: Whether we want to online the node
> * called by cpu_up() to online a node without onlined memory.
> */
> -int try_online_node(int nid)
> +static int __try_online_node(int nid, u64 start, bool set_node_online)
> {
> - pg_data_t *pgdat;
> - int ret;
> + pg_data_t *pgdat;
> + int ret = 1;
>
> if (node_online(nid))
> return 0;
>
> - mem_hotplug_begin();
> - pgdat = hotadd_new_pgdat(nid, 0);
> + pgdat = hotadd_new_pgdat(nid, start);
> if (!pgdat) {
> pr_err("Cannot online node %d due to NULL pgdat\n", nid);
> ret = -ENOMEM;
> goto out;
> }
> - node_set_online(nid);
> - ret = register_one_node(nid);
> - BUG_ON(ret);
> +
> + if (set_node_online) {
> + node_set_online(nid);
> + ret = register_one_node(nid);
> + BUG_ON(ret);
> + }
> out:
> + return ret;
> +}
> +
> +/*
> + * Users of this function always want to online/register the node
> + */
> +int try_online_node(int nid)
> +{
> + int ret;
> +
> + mem_hotplug_begin();
> + ret = __try_online_node (nid, 0, true);
> mem_hotplug_done();
> return ret;
> }
> @@ -1099,8 +1116,6 @@ static int online_memory_block(struct memory_block *mem, void *arg)
> int __ref add_memory_resource(int nid, struct resource *res, bool online)
> {
> u64 start, size;
> - pg_data_t *pgdat = NULL;
> - bool new_pgdat;
> bool new_node;
> int ret;
>
> @@ -1111,11 +1126,6 @@ int __ref add_memory_resource(int nid, struct resource *res, bool online)
> if (ret)
> return ret;
>
> - { /* Stupid hack to suppress address-never-null warning */
> - void *p = NODE_DATA(nid);
> - new_pgdat = !p;
> - }
> -
> mem_hotplug_begin();
>
> /*
> @@ -1126,17 +1136,14 @@ int __ref add_memory_resource(int nid, struct resource *res, bool online)
> */
> memblock_add_node(start, size, nid);
>
> - new_node = !node_online(nid);
> - if (new_node) {
> - pgdat = hotadd_new_pgdat(nid, start);
> - ret = -ENOMEM;
> - if (!pgdat)
> - goto error;
> - }
> + ret = __try_online_node (nid, start, false);
space before (
> + new_node = !!(ret > 0);
> + if (ret < 0)
> + goto error;
> +
>
> /* call arch's memory hotadd */
> ret = arch_add_memory(nid, start, size, NULL, true);
> -
> if (ret < 0)
> goto error;
>
> @@ -1180,8 +1187,8 @@ int __ref add_memory_resource(int nid, struct resource *res, bool online)
>
> error:
> /* rollback pgdat allocation and others */
> - if (new_pgdat && pgdat)
> - rollback_node_hotadd(nid, pgdat);
> + if (new_node)
> + rollback_node_hotadd(nid);
> memblock_remove(start, size);
>
> out:
