mm/memory_hotplug.c: improve comments

tang-chen · torvalds · commit 79a4dcefd325 · 2012-12-18T15:02:15.000-08:00
Signed-off-by: Tang Chen &lt;tangchen@cn.fujitsu.com&gt;
Cc: Jiang Liu &lt;jiang.liu@huawei.com&gt;
Cc: Lai Jiangshan &lt;laijs@cn.fujitsu.com&gt;
Cc: Wen Congyang &lt;wency@cn.fujitsu.com&gt;
Cc: Yasuaki Ishimatsu &lt;isimatu.yasuaki@jp.fujitsu.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
@@ -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,

Original file line number	Diff line number	Diff line change
`@@ -590,18 +590,21 @@ static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,`
`590`	`590`	`}`
`591`	`591`
`592`	`592`	`#ifdef CONFIG_MOVABLE_NODE`
`593`		`-/* when CONFIG_MOVABLE_NODE, we allow online node don't have normal memory */`
	`593`	`+/*`
	`594`	`+ * When CONFIG_MOVABLE_NODE, we permit onlining of a node which doesn't have`
	`595`	`+ * normal memory.`
	`596`	`+ */`
`594`	`597`	`static bool can_online_high_movable(struct zone *zone)`
`595`	`598`	`{`
`596`	`599`	`return true;`
`597`	`600`	`}`
`598`		`-#else /* #ifdef CONFIG_MOVABLE_NODE */`
	`601`	`+#else /* CONFIG_MOVABLE_NODE */`
`599`	`602`	`/* ensure every online node has NORMAL memory */`
`600`	`603`	`static bool can_online_high_movable(struct zone *zone)`
`601`	`604`	`{`
`602`	`605`	`return node_state(zone_to_nid(zone), N_NORMAL_MEMORY);`
`603`	`606`	`}`
`604`		`-#endif /* #ifdef CONFIG_MOVABLE_NODE */`
	`607`	`+#endif /* CONFIG_MOVABLE_NODE */`
`605`	`608`
`606`	`609`	`/* check which state of node_states will be changed when online memory */`
`607`	`610`	`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)`
`1112`	`1115`	`}`
`1113`	`1116`
`1114`	`1117`	`#ifdef CONFIG_MOVABLE_NODE`
`1115`		`-/* when CONFIG_MOVABLE_NODE, we allow online node don't have normal memory */`
	`1118`	`+/*`
	`1119`	`+ * When CONFIG_MOVABLE_NODE, we permit offlining of a node which doesn't have`
	`1120`	`+ * normal memory.`
	`1121`	`+ */`
`1116`	`1122`	`static bool can_offline_normal(struct zone *zone, unsigned long nr_pages)`
`1117`	`1123`	`{`
`1118`	`1124`	`return true;`
`1119`	`1125`	`}`
`1120`		`-#else /* #ifdef CONFIG_MOVABLE_NODE */`
	`1126`	`+#else /* CONFIG_MOVABLE_NODE */`
`1121`	`1127`	`/* ensure the node has NORMAL memory if it is still online */`
`1122`	`1128`	`static bool can_offline_normal(struct zone *zone, unsigned long nr_pages)`
`1123`	`1129`	`{`
`@@ -1141,7 +1147,7 @@ static bool can_offline_normal(struct zone *zone, unsigned long nr_pages)`
`1141`	`1147`	`*/`
`1142`	`1148`	`return present_pages == 0;`
`1143`	`1149`	`}`
`1144`		`-#endif /* #ifdef CONFIG_MOVABLE_NODE */`
	`1150`	`+#endif /* CONFIG_MOVABLE_NODE */`
`1145`	`1151`
`1146`	`1152`	`/* check which state of node_states will be changed when offline memory */`
`1147`	`1153`	`static void node_states_check_changes_offline(unsigned long nr_pages,`