Commit a6af2bc3 authored by Mel Gorman's avatar Mel Gorman Committed by Linus Torvalds

[PATCH] Avoid excessive sorting of early_node_map[]

find_min_pfn_for_node() and find_min_pfn_with_active_regions() sort
early_node_map[] on every call.  This is an excessive amount of sorting and
that can be avoided.  This patch always searches the whole early_node_map[]
in find_min_pfn_for_node() instead of returning the first value found.  The
map is then only sorted once when required.  Successfully boot tested on a
number of machines.

[[email protected]: cleanup]
Signed-off-by: default avatarMel Gorman <[email protected]>
Signed-off-by: default avatarAndrew Morton <[email protected]>
Signed-off-by: default avatarLinus Torvalds <[email protected]>
parent e10a4437
......@@ -2877,20 +2877,23 @@ static void __init sort_node_map(void)
cmp_node_active_region, NULL);
/* Find the lowest pfn for a node. This depends on a sorted early_node_map */
/* Find the lowest pfn for a node */
unsigned long __init find_min_pfn_for_node(unsigned long nid)
int i;
/* Regions in the early_node_map can be in any order */
unsigned long min_pfn = ULONG_MAX;
/* Assuming a sorted map, the first range found has the starting pfn */
for_each_active_range_index_in_nid(i, nid)
return early_node_map[i].start_pfn;
min_pfn = min(min_pfn, early_node_map[i].start_pfn);
printk(KERN_WARNING "Could not find start_pfn for node %lu\n", nid);
return 0;
if (min_pfn == ULONG_MAX) {
"Could not find start_pfn for node %lu\n", nid);
return 0;
return min_pfn;
......@@ -2939,6 +2942,9 @@ void __init free_area_init_nodes(unsigned long *max_zone_pfn)
unsigned long nid;
enum zone_type i;
/* Sort early_node_map as initialisation assumes it is sorted */
/* Record where the zone boundaries are */
memset(arch_zone_lowest_possible_pfn, 0,
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment