mm/page_alloc.c: pull out init code from build_all_zonelists

Pulling the code protected by if (system_state == SYSTEM_BOOTING) into
its own helper allows us to shrink .text a little. This relies on
build_all_zonelists already having a __ref annotation. Add a comment
explaining why so one doesn't have to track it down through git log.

The real saving comes in 3/5, ("mm/mm_init.c: Mark mminit_verify_zonelist
as __init"), where we save about 400 bytes

Signed-off-by: Rasmus Villemoes <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Vishnu Pratap Singh <[email protected]>
Cc: Pintu Kumar <[email protected]>
Cc: Michal Nazarewicz <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Paul Gortmaker <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Tim Chen <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Li Zefan <[email protected]>
Cc: Tejun Heo <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

1 files changed, 14 insertions, 3 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 8d52ab18fe0d..375327b8e932 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3871,18 +3871,29 @@ static int __build_all_zonelists(void *data)
 	return 0;
 }
 
+static noinline void __init
+build_all_zonelists_init(void)
+{
+	__build_all_zonelists(NULL);
+	mminit_verify_zonelist();
+	cpuset_init_current_mems_allowed();
+}
+
 /*
  * Called with zonelists_mutex held always
  * unless system_state == SYSTEM_BOOTING.
+ *
+ * __ref due to (1) call of __meminit annotated setup_zone_pageset
+ * [we're only called with non-NULL zone through __meminit paths] and
+ * (2) call of __init annotated helper build_all_zonelists_init
+ * [protected by SYSTEM_BOOTING].
  */
 void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
 {
 	set_zonelist_order();
 
 	if (system_state == SYSTEM_BOOTING) {
-		__build_all_zonelists(NULL);
-		mminit_verify_zonelist();
-		cpuset_init_current_mems_allowed();
+		build_all_zonelists_init();
 	} else {
 #ifdef CONFIG_MEMORY_HOTPLUG
 		if (zone)