[RFC] free_area[] bitmap elimination [2/3]

Hiroyuki KAMEZAWA
2004-08-21T02:32:59Z

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This part is for alloc_pages()

--
--the clue is these footmarks leading to the door.--
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>

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removing bitmap operation in page allocation.

---

linux-2.6.8.1-kame-kamezawa/mm/page_alloc.c | 8 ++------
1 files changed, 2 insertions(+), 6 deletions(-)

diff -puN mm/page_alloc.c~eliminate-bitmap-p03 mm/page_alloc.c
--- linux-2.6.8.1-kame/mm/page_alloc.c~eliminate-bitmap-p03 2004-08-21 08:54:43.285765800 +0900
+++ linux-2.6.8.1-kame-kamezawa/mm/page_alloc.c 2004-08-21 08:54:43.292764736 +0900
@@ -287,8 +287,6 @@ void __free_pages_ok(struct page *page,
free_pages_bulk(page_zone(page), 1, &list, order);
}

-#define MARK_USED(index, order, area) \
- __change_bit((index) >> (1+(order)), (area)->map)

/*
* The order of subdivision here is critical for the IO subsystem.
@@ -315,9 +313,10 @@ expand(struct zone *zone, struct page *p
high--;
size >>= 1;
BUG_ON(bad_range(zone, &page[size]));
+ set_page_order(&page[size],high);
list_add(&page[size].lru, &area->free_list);
- MARK_USED(index + size, high, area);
}
+ invalidate_page_order(page);
return page;
}

@@ -378,12 +377,9 @@ static struct page *__rmqueue(struct zon
area = zone->free_area + current_order;
if (list_empty(&area->free_list))
continue;
-
page = list_entry(area->free_list.next, struct page, lru);
list_del(&page->lru);
index = page - zone->zone_mem_map;
- if (current_order != MAX_ORDER-1)
- MARK_USED(index, current_order, area);
zone->free_pages -= 1UL << order;
return expand(zone, page, index, order, current_order, area);
}

_