From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756193AbZEHPKk (ORCPT ); Fri, 8 May 2009 11:10:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753833AbZEHPKa (ORCPT ); Fri, 8 May 2009 11:10:30 -0400 Received: from courier.cs.helsinki.fi ([128.214.9.1]:51415 "EHLO mail.cs.helsinki.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752570AbZEHPK3 (ORCPT ); Fri, 8 May 2009 11:10:29 -0400 Subject: [PATCH 1/2] mm: Introduce GFP_PANIC for early-boot allocations From: Pekka Enberg To: akpm@linux-foundation.org Cc: gorcunov@openvz.org, kosaki.motohiro@jp.fujitsu.com, mel@csn.ul.ie, cl@linux-foundation.org, riel@redhat.com, linux-kernel@vger.kernel.org, mingo@elte.hu, rientjes@google.com Date: Fri, 08 May 2009 18:10:28 +0300 Message-Id: <1241795428.28600.60.camel@penberg-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 7bit X-Mailer: Evolution 2.24.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Pekka Enberg This patch introduces a GFP_PANIC flag that can be used as an annotation that an early-boot call to kmalloc() or alloc_pages() is expected to never fail. To save one GFP flag bit, use a combination of __GFP_NOFAIL and __GFP_NOREPEAT to make sure we always end up in the "nopage" path of the page allocator if an allocation fails. [ gorcunov@openvz.org: initial version of the patch ] Cc: Christoph Lameter Cc: David Rientjes Cc: KOSAKI Motohiro Cc: Mel Gorman Cc: Rik van Riel Signed-off-by: Pekka Enberg --- Andrew, this one is rebased on top of -mm. include/linux/gfp.h | 1 + mm/page_alloc.c | 12 ++++++++++-- 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/include/linux/gfp.h b/include/linux/gfp.h index c7429b8..2e76e7b 100644 --- a/include/linux/gfp.h +++ b/include/linux/gfp.h @@ -71,6 +71,7 @@ struct vm_area_struct; #define GFP_HIGHUSER_MOVABLE (__GFP_WAIT | __GFP_IO | __GFP_FS | \ __GFP_HARDWALL | __GFP_HIGHMEM | \ __GFP_MOVABLE) +#define GFP_PANIC (__GFP_NOFAIL | __GFP_NORETRY) #ifdef CONFIG_NUMA #define GFP_THISNODE (__GFP_THISNODE | __GFP_NOWARN | __GFP_NORETRY) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index be0ed90..eb8d953 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1516,8 +1516,11 @@ static inline int should_alloc_retry(gfp_t gfp_mask, unsigned int order, unsigned long pages_reclaimed) { - /* Do not loop if specifically requested */ - if (gfp_mask & __GFP_NORETRY) + /* + * Do not loop if specifically requested. Note: GFP_PANIC sets both + * flags. + */ + if ((gfp_mask & __GFP_NORETRY) && !(gfp_mask & __GFP_NOFAIL)) return 0; /* @@ -1813,6 +1816,11 @@ rebalance: } nopage: + if (unlikely((gfp_mask & GFP_PANIC) == GFP_PANIC)) { + show_mem(); + panic("Out of memory: %s order: %d, gfp_mask:0x%x\n", + p->comm, order, gfp_mask); + } if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) { printk(KERN_WARNING "%s: page allocation failure." " order:%d, mode:0x%x\n", -- 1.5.6.3