Subject: Be more agressive about stealing when MIGRATE_RECLAIMABLE allocations
fallback
MIGRATE_RECLAIMABLE allocations tend to be very bursty in nature like when
updatedb starts. It is likely this will occur in situations where MAX_ORDER
blocks of pages are not free. This means that updatedb can scatter
MIGRATE_RECLAIMABLE pages throughout the address space. This patch is more
agressive about stealing blocks of pages for MIGRATE_RECLAIMABLE.
Signed-off-by: Mel Gorman <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
---
mm/page_alloc.c | 23 +++++++++++++++++------
1 file changed, 17 insertions(+), 6 deletions(-)
diff -rup -X /usr/src/patchset-0.6/bin//dontdiff
linux-2.6.23-rc5-011-bias-the-placement-of-kernel-pages-at-lower-pfns/mm/page_alloc.c
linux-2.6.23-rc5-012-be-more-agressive-about-stealing-when-migrate_reclaimable-allocations-fallback/mm/page_alloc.c
---
linux-2.6.23-rc5-011-bias-the-placement-of-kernel-pages-at-lower-pfns/mm/page_alloc.c
2007-09-02 16:22:27.000000000 +0100
+++
linux-2.6.23-rc5-012-be-more-agressive-about-stealing-when-migrate_reclaimable-allocations-fallback/mm/page_alloc.c
2007-09-02 16:22:47.000000000 +0100
@@ -713,7 +713,7 @@ int move_freepages(struct zone *zone,
{
struct page *page;
unsigned long order;
- int blocks_moved = 0;
+ int pages_moved = 0;
#ifndef CONFIG_HOLES_IN_ZONE
/*
@@ -742,10 +742,10 @@ int move_freepages(struct zone *zone,
list_add(&page->lru,
&zone->free_area[order].free_list[migratetype]);
page += 1 << order;
- blocks_moved++;
+ pages_moved += 1 << order;
}
- return blocks_moved;
+ return pages_moved;
}
int move_freepages_block(struct zone *zone, struct page *page, int migratetype)
@@ -817,11 +817,22 @@ static struct page *__rmqueue_fallback(s
/*
* If breaking a large block of pages, move all free
- * pages to the preferred allocation list
+ * pages to the preferred allocation list. If falling
+ * back for a reclaimable kernel allocation, be more
+ * agressive about taking ownership of free pages
*/
- if (unlikely(current_order >= (pageblock_order >> 1)))
+ if (unlikely(current_order >= (pageblock_order >> 1)) ||
+ start_migratetype ==
MIGRATE_RECLAIMABLE) {
+ unsigned long pages;
+ pages = move_freepages_block(zone, page,
+
start_migratetype);
+
+ /* Claim the whole block if over half of it is
free */
+ if (pages >= (1 << (pageblock_order-1)))
+ set_pageblock_migratetype(page,
+
start_migratetype);
+
migratetype = start_migratetype;
- move_freepages_block(zone, page, migratetype);
}
/* Remove the page from the freelists */
-
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