From patchwork Fri Aug 12 10:58:24 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marek Szyprowski X-Patchwork-Id: 1060432 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter2.kernel.org (8.14.4/8.14.4) with ESMTP id p7CAwjAW021719 for ; Fri, 12 Aug 2011 10:58:46 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752537Ab1HLK6i (ORCPT ); Fri, 12 Aug 2011 06:58:38 -0400 Received: from mailout2.w1.samsung.com ([210.118.77.12]:50039 "EHLO mailout2.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751311Ab1HLK6h (ORCPT ); Fri, 12 Aug 2011 06:58:37 -0400 Received: from spt2.w1.samsung.com (mailout2.w1.samsung.com [210.118.77.12]) by mailout2.w1.samsung.com (iPlanet Messaging Server 5.2 Patch 2 (built Jul 14 2004)) with ESMTP id <0LPT008XUAHN2J@mailout2.w1.samsung.com>; Fri, 12 Aug 2011 11:58:36 +0100 (BST) Received: from linux.samsung.com ([106.116.38.10]) by spt2.w1.samsung.com (iPlanet Messaging Server 5.2 Patch 2 (built Jul 14 2004)) with ESMTPA id <0LPT00B1TAHLXZ@spt2.w1.samsung.com>; Fri, 12 Aug 2011 11:58:34 +0100 (BST) Received: from mcdsrvbld02.digital.local (unknown [106.116.37.23]) by linux.samsung.com (Postfix) with ESMTP id 51DE927005E; Fri, 12 Aug 2011 13:00:00 +0200 (CEST) Date: Fri, 12 Aug 2011 12:58:24 +0200 From: Marek Szyprowski Subject: [PATCH 2/9] mm: alloc_contig_freed_pages() added In-reply-to: <1313146711-1767-1-git-send-email-m.szyprowski@samsung.com> To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-media@vger.kernel.org, linux-mm@kvack.org, linaro-mm-sig@lists.linaro.org Cc: Michal Nazarewicz , Marek Szyprowski , Kyungmin Park , Russell King , Andrew Morton , KAMEZAWA Hiroyuki , Ankita Garg , Daniel Walker , Mel Gorman , Arnd Bergmann , Jesse Barker , Jonathan Corbet , Shariq Hasnain , Chunsang Jeong Message-id: <1313146711-1767-3-git-send-email-m.szyprowski@samsung.com> MIME-version: 1.0 X-Mailer: git-send-email 1.7.5.4 Content-type: TEXT/PLAIN Content-transfer-encoding: 7BIT References: <1313146711-1767-1-git-send-email-m.szyprowski@samsung.com> Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter2.kernel.org [140.211.167.43]); Fri, 12 Aug 2011 10:58:46 +0000 (UTC) From: KAMEZAWA Hiroyuki 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 Signed-off-by: Michal Nazarewicz Signed-off-by: Kyungmin Park Signed-off-by: Marek Szyprowski CC: Michal Nazarewicz Acked-by: Arnd Bergmann --- include/linux/page-isolation.h | 3 ++ mm/page_alloc.c | 44 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 47 insertions(+), 0 deletions(-) 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 6e8ecb6..ad6ae3f 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.