The patch titled
Bias the placement of kernel pages at lower PFNs
has been removed from the -mm tree. Its filename was
bias-the-placement-of-kernel-pages-at-lower-pfns.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
Subject: Bias the placement of kernel pages at lower PFNs
From: Mel Gorman <mel@xxxxxxxxx>
This patch chooses blocks with lower PFNs when placing kernel allocations.
This is particularly important during fallback in low memory situations to
stop unmovable pages being placed throughout the entire address space.
Signed-off-by: Mel Gorman <mel@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_alloc.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff -puN mm/page_alloc.c~bias-the-placement-of-kernel-pages-at-lower-pfns mm/page_alloc.c
--- a/mm/page_alloc.c~bias-the-placement-of-kernel-pages-at-lower-pfns
+++ a/mm/page_alloc.c
@@ -765,6 +765,23 @@ int move_freepages_block(struct zone *zo
return move_freepages(zone, start_page, end_page, migratetype);
}
+/* Return the page with the lowest PFN in the list */
+static struct page *min_page(struct list_head *list)
+{
+ unsigned long min_pfn = -1UL;
+ struct page *min_page = NULL, *page;;
+
+ list_for_each_entry(page, list, lru) {
+ unsigned long pfn = page_to_pfn(page);
+ if (pfn < min_pfn) {
+ min_pfn = pfn;
+ min_page = page;
+ }
+ }
+
+ return min_page;
+}
+
/* Remove an element from the buddy allocator from the fallback list */
static struct page *__rmqueue_fallback(struct zone *zone, int order,
int start_migratetype)
@@ -795,8 +812,11 @@ retry:
if (list_empty(&area->free_list[migratetype]))
continue;
+ /* Bias kernel allocations towards low pfns */
page = list_entry(area->free_list[migratetype].next,
struct page, lru);
+ if (unlikely(start_migratetype != MIGRATE_MOVABLE))
+ page = min_page(&area->free_list[migratetype]);
area->nr_free--;
/*
_
Patches currently in -mm which might be from mel@xxxxxxxxx are
origin.patch
ext2-reservations.patch
page-owner-tracking-leak-detector.patch
add-debugging-aid-for-memory-initialisation-problems.patch
-
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