diff options
author | KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> | 2011-12-19 11:40:38 +0800 |
---|---|---|
committer | Sebastien Jan <s-jan@ti.com> | 2011-12-20 10:05:50 +0100 |
commit | 6a1a99201b151cb689f0b9099de0f471d908b4a0 (patch) | |
tree | e5708cc0f15e77af8da0f59f5d9ed915d709c75f /mm | |
parent | 3892a05cc45c57be55158067382a199ecdb8092b (diff) |
This commit introduces alloc_contig_freed_pages() function
which allocates (ie. removes from buddy system) free pages
in range. Caller has to guarantee that all pages in range
are in buddy system.
Along with this function, a free_contig_pages() function is
provided which frees all (or a subset of) pages allocated
with alloc_contig_free_pages().
Michal Nazarewicz has modified the function to make it easier
to allocate not MAX_ORDER_NR_PAGES aligned pages by making it
return pfn of one-past-the-last allocated page.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Signed-off-by: Michal Nazarewicz <m.nazarewicz@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
CC: Michal Nazarewicz <mina86@xxxxxxxxxx>
Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/page_alloc.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 6e8ecb6e021c..ad6ae3f20565 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5668,6 +5668,50 @@ out: spin_unlock_irqrestore(&zone->lock, flags); } +unsigned long alloc_contig_freed_pages(unsigned long start, unsigned long end, + gfp_t flag) +{ + unsigned long pfn = start, count; + struct page *page; + struct zone *zone; + int order; + + VM_BUG_ON(!pfn_valid(start)); + zone = page_zone(pfn_to_page(start)); + + spin_lock_irq(&zone->lock); + + page = pfn_to_page(pfn); + for (;;) { + VM_BUG_ON(page_count(page) || !PageBuddy(page)); + list_del(&page->lru); + order = page_order(page); + zone->free_area[order].nr_free--; + rmv_page_order(page); + __mod_zone_page_state(zone, NR_FREE_PAGES, -(1UL << order)); + pfn += 1 << order; + if (pfn >= end) + break; + VM_BUG_ON(!pfn_valid(pfn)); + page += 1 << order; + } + + spin_unlock_irq(&zone->lock); + + /* After this, pages in the range can be freed one be one */ + page = pfn_to_page(start); + for (count = pfn - start; count; --count, ++page) + prep_new_page(page, 0, flag); + + return pfn; +} + +void free_contig_pages(struct page *page, int nr_pages) +{ + for (; nr_pages; --nr_pages, ++page) + __free_page(page); +} + #ifdef CONFIG_MEMORY_HOTREMOVE /* * All pages in the range must be isolated before calling this. |