[PATCH] Hugepages: Use page_to_nid rather than traversing zone pointers

I found two location in hugetlb.c where we chase pointer instead of using
page_to_nid().  Page_to_nid is more effective and can get the node directly
from page flags.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index df499973255fdfb3397a92221cb5217bcb70d10d..3aceadce1a762a8c4e273913d07230c3813efb82 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -177,7 +177,7 @@ static void update_and_free_page(struct page *page)
 {
        int i;
        nr_huge_pages--;
-       nr_huge_pages_node[page_zone(page)->zone_pgdat->node_id]--;
+       nr_huge_pages_node[page_to_nid(page)]--;
        for (i = 0; i < (HPAGE_SIZE / PAGE_SIZE); i++) {
                page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced |
                                1 << PG_dirty | 1 << PG_active | 1 << PG_reserved |
@@ -191,7 +191,8 @@ static void update_and_free_page(struct page *page)
 #ifdef CONFIG_HIGHMEM
 static void try_to_free_low(unsigned long count)
 {
-       int i, nid;
+       int i;
+
        for (i = 0; i < MAX_NUMNODES; ++i) {
                struct page *page, *next;
                list_for_each_entry_safe(page, next, &hugepage_freelists[i], lru) {
@@ -199,9 +200,8 @@ static void try_to_free_low(unsigned long count)
                                continue;
                        list_del(&page->lru);
                        update_and_free_page(page);
-                       nid = page_zone(page)->zone_pgdat->node_id;
                        free_huge_pages--;
-                       free_huge_pages_node[nid]--;
+                       free_huge_pages_node[page_to_nid(page)]--;
                        if (count >= nr_huge_pages)
                                return;
                }