The patch titled
Avoid excessive sorting of early_node_map[]
has been added to the -mm tree. Its filename is
avoid-excessive-sorting-of-early_node_map.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: Avoid excessive sorting of early_node_map[]
From: Mel Gorman <mel@xxxxxxxxx>
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.
Signed-off-by: Mel Gorman <mel@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
mm/page_alloc.c | 20 +++++++++++++-------
1 files changed, 13 insertions(+), 7 deletions(-)
diff -puN mm/page_alloc.c~avoid-excessive-sorting-of-early_node_map mm/page_alloc.c
--- a/mm/page_alloc.c~avoid-excessive-sorting-of-early_node_map
+++ a/mm/page_alloc.c
@@ -2865,20 +2865,23 @@ 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 */
- sort_node_map();
+ unsigned long min_pfn = -1UL;
/* 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 == -1UL) {
+ printk(KERN_WARNING
+ "Could not find start_pfn for node %lu\n", nid);
+ return 0;
+ }
+
+ return min_pfn;
}
/**
@@ -2927,6 +2930,9 @@ void __init free_area_init_nodes(unsigne
unsigned long nid;
enum zone_type i;
+ /* Sort early_node_map as initialisation assumes it is sorted */
+ sort_node_map();
+
/* Record where the zone boundaries are */
memset(arch_zone_lowest_possible_pfn, 0,
sizeof(arch_zone_lowest_possible_pfn));
_
Patches currently in -mm which might be from mel@xxxxxxxxx are
avoid-excessive-sorting-of-early_node_map.patch
ext2-reservations.patch
add-debugging-aid-for-memory-initialisation-problems.patch
add-debugging-aid-for-memory-initialisation-problems-fix.patch
-
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