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author | Mel Gorman <mel@csn.ul.ie> | 2007-10-16 01:25:51 -0700 |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-16 09:43:00 -0700 |
commit | c361be55b3128474aa66d31092db330b07539103 (patch) | |
tree | 9ce134f4e679144d28f5c32924bdba999a1aae6b | |
parent | e2c55dc87f4a398b9c4dcc702dbc23a07fe14e23 (diff) | |
download | kernel_samsung_crespo-c361be55b3128474aa66d31092db330b07539103.zip kernel_samsung_crespo-c361be55b3128474aa66d31092db330b07539103.tar.gz kernel_samsung_crespo-c361be55b3128474aa66d31092db330b07539103.tar.bz2 |
Move free pages between lists on steal
When a fallback occurs, there will be free pages for one allocation type
stored on the list for another. When a large steal occurs, this patch will
move all the free pages within one list to the other.
[y-goto@jp.fujitsu.com: fix BUG_ON check at move_freepages()]
[apw@shadowen.org: Move to using pfn_valid_within()]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andy Whitcroft <andyw@uk.ibm.com>
Cc: Bob Picco <bob.picco@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | mm/page_alloc.c | 74 |
1 files changed, 71 insertions, 3 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index aa7e5d2..d575a3e 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -680,6 +680,72 @@ static int fallbacks[MIGRATE_TYPES][MIGRATE_TYPES-1] = { [MIGRATE_MOVABLE] = { MIGRATE_UNMOVABLE }, }; +/* + * Move the free pages in a range to the free lists of the requested type. + * Note that start_page and end_pages are not aligned in a MAX_ORDER_NR_PAGES + * boundary. If alignment is required, use move_freepages_block() + */ +int move_freepages(struct zone *zone, + struct page *start_page, struct page *end_page, + int migratetype) +{ + struct page *page; + unsigned long order; + int blocks_moved = 0; + +#ifndef CONFIG_HOLES_IN_ZONE + /* + * page_zone is not safe to call in this context when + * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant + * anyway as we check zone boundaries in move_freepages_block(). + * Remove at a later date when no bug reports exist related to + * CONFIG_PAGE_GROUP_BY_MOBILITY + */ + BUG_ON(page_zone(start_page) != page_zone(end_page)); +#endif + + for (page = start_page; page <= end_page;) { + if (!pfn_valid_within(page_to_pfn(page))) { + page++; + continue; + } + + if (!PageBuddy(page)) { + page++; + continue; + } + + order = page_order(page); + list_del(&page->lru); + list_add(&page->lru, + &zone->free_area[order].free_list[migratetype]); + page += 1 << order; + blocks_moved++; + } + + return blocks_moved; +} + +int move_freepages_block(struct zone *zone, struct page *page, int migratetype) +{ + unsigned long start_pfn, end_pfn; + struct page *start_page, *end_page; + + start_pfn = page_to_pfn(page); + start_pfn = start_pfn & ~(MAX_ORDER_NR_PAGES-1); + start_page = pfn_to_page(start_pfn); + end_page = start_page + MAX_ORDER_NR_PAGES - 1; + end_pfn = start_pfn + MAX_ORDER_NR_PAGES - 1; + + /* Do not cross zone boundaries */ + if (start_pfn < zone->zone_start_pfn) + start_page = page; + if (end_pfn >= zone->zone_start_pfn + zone->spanned_pages) + return 0; + + return move_freepages(zone, start_page, end_page, migratetype); +} + /* Remove an element from the buddy allocator from the fallback list */ static struct page *__rmqueue_fallback(struct zone *zone, int order, int start_migratetype) @@ -704,11 +770,13 @@ static struct page *__rmqueue_fallback(struct zone *zone, int order, area->nr_free--; /* - * If breaking a large block of pages, place the buddies - * on the preferred allocation list + * If breaking a large block of pages, move all free + * pages to the preferred allocation list */ - if (unlikely(current_order >= MAX_ORDER / 2)) + if (unlikely(current_order >= MAX_ORDER / 2)) { migratetype = start_migratetype; + move_freepages_block(zone, page, migratetype); + } /* Remove the page from the freelists */ list_del(&page->lru); |