| Message ID | 1309851710-3828-3-git-send-email-m.szyprowski@samsung.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On Tuesday 05 July 2011, Marek Szyprowski wrote: > From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> > > 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@jp.fujitsu.com> > Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com> > Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> > Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> > CC: Michal Nazarewicz <mina86@mina86.com> Acked-by: Arnd Bergmann <arnd@arndb.de> -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/linux/page-isolation.h b/include/linux/page-isolation.h index 58cdbac..f1417ed 100644 --- a/include/linux/page-isolation.h +++ b/include/linux/page-isolation.h @@ -32,6 +32,9 @@ test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn); */ extern int set_migratetype_isolate(struct page *page); extern void unset_migratetype_isolate(struct page *page); +extern unsigned long alloc_contig_freed_pages(unsigned long start, + unsigned long end, gfp_t flag); +extern void free_contig_pages(struct page *page, int nr_pages); /* * For migration. diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 4e8985a..00e9b24 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5600,6 +5600,50 @@ 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.