On (23/04/07 19:32), Mel Gorman didst pronounce:
> There
> was a second problem that showed up while testing this in relation to the
> bootmem allocator assumptions about zone boundary alignment. I'll follow up
> this mail with the patch in case you are seeing that problem.
>
Tony Luck added to cc list as I believe he had a lot to do with the speed
improvements within the bootmem allocator and might suggest a better fix.
Subject: Check zone boundaries when freeing bootmem
Zone boundaries do not have to be aligned to MAX_ORDER_NR_PAGES. However,
during boot, there is an implicit assumption that they are aligned to a
BITS_PER_LONG boundary when freeing pages as quickly as possible. This
patch checks the zone boundaries when freeing pages from the bootmem allocator.
Signed-off-by: Mel Gorman <[EMAIL PROTECTED]>
diff -rup -X /usr/src/patchset-0.6/bin//dontdiff
linux-2.6.21-rc6-mm1-002_ia64cmdline/mm/bootmem.c
linux-2.6.21-rc6-mm1-003_bootmem_zonecheck/mm/bootmem.c
--- linux-2.6.21-rc6-mm1-002_ia64cmdline/mm/bootmem.c 2007-04-06
03:36:56.000000000 +0100
+++ linux-2.6.21-rc6-mm1-003_bootmem_zonecheck/mm/bootmem.c 2007-04-23
18:58:10.000000000 +0100
@@ -302,13 +302,15 @@ found:
static unsigned long __init free_all_bootmem_core(pg_data_t *pgdat)
{
- struct page *page;
+ struct page *page = NULL, *end_page = NULL;
unsigned long pfn;
bootmem_data_t *bdata = pgdat->bdata;
unsigned long i, count, total = 0;
unsigned long idx;
unsigned long *map;
int gofast = 0;
+ int gofast_order = ffs(BITS_PER_LONG) - 1;
+ int gofast_size = 1 << gofast_order;
BUG_ON(!bdata->node_bootmem_map);
@@ -324,19 +326,21 @@ static unsigned long __init free_all_boo
for (i = 0; i < idx; ) {
unsigned long v = ~map[i / BITS_PER_LONG];
- if (gofast && v == ~0UL) {
- int order;
-
+ if (v) {
page = pfn_to_page(pfn);
+ end_page = page + gofast_size - 1;
+ }
+
+ /* Do not cross zone boundaries when fast freeing */
+ if (gofast && v == ~0UL &&
+ page_zone_id(page) == page_zone_id(end_page)) {
count += BITS_PER_LONG;
- order = ffs(BITS_PER_LONG) - 1;
- __free_pages_bootmem(page, order);
+ __free_pages_bootmem(page, gofast_order);
i += BITS_PER_LONG;
page += BITS_PER_LONG;
} else if (v) {
unsigned long m;
- page = pfn_to_page(pfn);
for (m = 1; m && i < idx; m<<=1, page++, i++) {
if (v & m) {
count++;
-
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