From 01b0f19707c51ef247404e6af1d4a97a11ba34f7 Mon Sep 17 00:00:00 2001 From: Toshi Kani Date: Tue, 12 Nov 2013 15:07:25 -0800 Subject: cpu/mem hotplug: add try_online_node() for cpu_up() cpu_up() has #ifdef CONFIG_MEMORY_HOTPLUG code blocks, which call mem_online_node() to put its node online if offlined and then call build_all_zonelists() to initialize the zone list. These steps are specific to memory hotplug, and should be managed in mm/memory_hotplug.c. lock_memory_hotplug() should also be held for the whole steps. For this reason, this patch replaces mem_online_node() with try_online_node(), which performs the whole steps with lock_memory_hotplug() held. try_online_node() is named after try_offline_node() as they have similar purpose. There is no functional change in this patch. Signed-off-by: Toshi Kani Reviewed-by: Yasuaki Ishimatsu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memory_hotplug.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) (limited to 'mm') diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 5118028468eb..8285346be663 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1043,17 +1043,23 @@ static void rollback_node_hotadd(int nid, pg_data_t *pgdat) } -/* +/** + * try_online_node - online a node if offlined + * * called by cpu_up() to online a node without onlined memory. */ -int mem_online_node(int nid) +int try_online_node(int nid) { pg_data_t *pgdat; int ret; + if (node_online(nid)) + return 0; + lock_memory_hotplug(); pgdat = hotadd_new_pgdat(nid, 0); if (!pgdat) { + pr_err("Cannot online node %d due to NULL pgdat\n", nid); ret = -ENOMEM; goto out; } @@ -1061,6 +1067,12 @@ int mem_online_node(int nid) ret = register_one_node(nid); BUG_ON(ret); + if (pgdat->node_zonelists->_zonerefs->zone == NULL) { + mutex_lock(&zonelists_mutex); + build_all_zonelists(NULL, NULL); + mutex_unlock(&zonelists_mutex); + } + out: unlock_memory_hotplug(); return ret; -- cgit v1.2.3-59-g8ed1b