On Wed, Jul 10, 2002 at 01:59:17AM -0700, William Lee Irwin III wrote:
> This patch implements deferred coalescing for the Linux page-level
[...]
> TODO:
[...]
> (5) use split_free_pages() to recover pages from higher-order
> deferred queues to avoid spuriously failing under fragmentation
Okay, people bugged me about this so here it is, testbooted on an
8cpu 16GB i386 box:
Cheers,
Bill
===== mm/page_alloc.c 1.129 vs edited =====
--- 1.129/mm/page_alloc.c Wed Jul 10 22:09:41 2002
+++ edited/mm/page_alloc.c Fri Jul 12 22:55:45 2002
@@ -344,6 +344,26 @@
}
}
+static struct page *FASTCALL(steal_deferred_page(zone_t *, int));
+static struct page *steal_deferred_page(zone_t *zone, int order)
+{
+ struct page *page;
+ free_area_t *area = zone->free_area;
+ int found_order;
+
+ for (found_order = order+1; found_order < MAX_ORDER; ++found_order)
+ if (!list_empty(&area[found_order].deferred_pages))
+ goto found_page;
+
+ return NULL;
+
+found_page:
+ page = list_entry(area[found_order].deferred_pages.next, struct page, list);
+ list_del(&page->list);
+ area[found_order].locally_free--;
+ split_pages(zone, page, order, found_order);
+}
+
#ifdef CONFIG_SOFTWARE_SUSPEND
int is_head_of_free_region(struct page *page)
{
@@ -391,8 +411,12 @@
area->locally_free--;
} else
page = buddy_alloc(zone, order);
- if (unlikely(!page))
+ if (unlikely(!page)) {
+ page = steal_deferred_page(zone, order);
+ if (likely(!page))
goto out;
+ }
+
prep_new_page(page);
area->active++;
zone->free_pages -= 1UL << order;
-
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This archive was generated by hypermail 2b29 : Mon Jul 15 2002 - 22:00:25 EST