mm/memory_hotplug.c: improve comments

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Tang Chen 2012-12-18 14:23:24 -08:00 committed by Linus Torvalds
parent 7179e7bf45
commit 79a4dcefd3

View file

@ -590,18 +590,21 @@ static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,
}
#ifdef CONFIG_MOVABLE_NODE
/* when CONFIG_MOVABLE_NODE, we allow online node don't have normal memory */
/*
* When CONFIG_MOVABLE_NODE, we permit onlining of a node which doesn't have
* normal memory.
*/
static bool can_online_high_movable(struct zone *zone)
{
return true;
}
#else /* #ifdef CONFIG_MOVABLE_NODE */
#else /* CONFIG_MOVABLE_NODE */
/* ensure every online node has NORMAL memory */
static bool can_online_high_movable(struct zone *zone)
{
return node_state(zone_to_nid(zone), N_NORMAL_MEMORY);
}
#endif /* #ifdef CONFIG_MOVABLE_NODE */
#endif /* CONFIG_MOVABLE_NODE */
/* check which state of node_states will be changed when online memory */
static void node_states_check_changes_online(unsigned long nr_pages,
@ -1112,12 +1115,15 @@ check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
}
#ifdef CONFIG_MOVABLE_NODE
/* when CONFIG_MOVABLE_NODE, we allow online node don't have normal memory */
/*
* When CONFIG_MOVABLE_NODE, we permit offlining of a node which doesn't have
* normal memory.
*/
static bool can_offline_normal(struct zone *zone, unsigned long nr_pages)
{
return true;
}
#else /* #ifdef CONFIG_MOVABLE_NODE */
#else /* CONFIG_MOVABLE_NODE */
/* ensure the node has NORMAL memory if it is still online */
static bool can_offline_normal(struct zone *zone, unsigned long nr_pages)
{
@ -1141,7 +1147,7 @@ static bool can_offline_normal(struct zone *zone, unsigned long nr_pages)
*/
return present_pages == 0;
}
#endif /* #ifdef CONFIG_MOVABLE_NODE */
#endif /* CONFIG_MOVABLE_NODE */
/* check which state of node_states will be changed when offline memory */
static void node_states_check_changes_offline(unsigned long nr_pages,