Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765639AbZFQMMK (ORCPT ); Wed, 17 Jun 2009 08:12:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761916AbZFQML6 (ORCPT ); Wed, 17 Jun 2009 08:11:58 -0400 Received: from cam-admin0.cambridge.arm.com ([193.131.176.58]:48247 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755769AbZFQML5 (ORCPT ); Wed, 17 Jun 2009 08:11:57 -0400 Subject: Re: WARNING: at mm/page_alloc.c:1159 get_page_from_freelist+0x325/0x655() From: Catalin Marinas To: Ingo Molnar Cc: Andrew Morton , Mel Gorman , torvalds@linux-foundation.org, fengguang.wu@intel.com, Pekka Enberg , linux-kernel@vger.kernel.org In-Reply-To: <20090617113120.GA5061@elte.hu> References: <200906162232.n5GMWRZe026963@imap1.linux-foundation.org> <20090616223649.719ea378.akpm@linux-foundation.org> <20090617111800.GA15261@elte.hu> <20090617113120.GA5061@elte.hu> Content-Type: text/plain Organization: ARM Ltd Date: Wed, 17 Jun 2009 13:11:17 +0100 Message-Id: <1245240677.11889.17.camel@pc1117.cambridge.arm.com> Mime-Version: 1.0 X-Mailer: Evolution 2.22.3.1 Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 17 Jun 2009 12:11:18.0251 (UTC) FILETIME=[B81D43B0:01C9EF44] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2988 Lines: 70 On Wed, 2009-06-17 at 13:31 +0200, Ingo Molnar wrote: > a new warning started popping up today, in the new page allocator > code. The allocation came from kmemleak: > > WARNING: at mm/page_alloc.c:1159 get_page_from_freelist+0x325/0x655() > Hardware name: System Product Name > Modules linked in: > Pid: 4367, comm: ifup Not tainted 2.6.30-tip-04303-g5ada65e-dirty #54431 > Call Trace: > [] ? get_page_from_freelist+0x325/0x655 > [] warn_slowpath_common+0x88/0xcb > [] warn_slowpath_null+0x22/0x38 > [] get_page_from_freelist+0x325/0x655 > [] __alloc_pages_nodemask+0x14c/0x5b0 > [] ? deactivate_slab+0xce/0x16b > [] ? native_sched_clock+0x40/0x79 > [] ? deactivate_slab+0xce/0x16b > [] ? deactivate_slab+0xce/0x16b > [] alloc_pages_current+0xcc/0xeb > [] alloc_slab_page+0x2a/0x7e > [] new_slab+0x5b/0x210 > [] ? deactivate_slab+0xe7/0x16b > [] __slab_alloc+0x214/0x3da > [] ? kmemleak_alloc+0x83/0x35a > [] ? kmemleak_alloc+0x83/0x35a > [] kmem_cache_alloc+0xac/0x14e > [] kmemleak_alloc+0x83/0x35a > [] ? cfq_get_queue+0x101/0x231 > [] kmem_cache_alloc_node+0xf8/0x177 > [] ? cfq_get_queue+0x101/0x231 > [] cfq_get_queue+0x101/0x231 Kmemleak needs to allocate memory for the pointer tracing and it currently passes the same gfp flags as those used by the original caller. In this case cfq_find_alloc_queue uses __GFP_NOFAIL. The reason for this was to avoid GFP_ATOMIC if the caller wasn't requiring it. I think the approach below is better: diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 58ec86c..46c9c93 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -462,7 +462,7 @@ static void create_object(unsigned long ptr, size_t size, int min_count, struct prio_tree_node *node; struct stack_trace trace; - object = kmem_cache_alloc(object_cache, gfp & ~GFP_SLAB_BUG_MASK); + object = kmem_cache_alloc(object_cache, gfp & (GFP_KERNEL | GFP_ATOMIC)); if (!object) { kmemleak_panic("kmemleak: Cannot allocate a kmemleak_object " "structure\n"); @@ -636,7 +636,7 @@ static void add_scan_area(unsigned long ptr, unsigned long offset, return; } - area = kmem_cache_alloc(scan_area_cache, gfp & ~GFP_SLAB_BUG_MASK); + area = kmem_cache_alloc(scan_area_cache, gfp & (GFP_KERNEL | GFP_ATOMIC)); if (!area) { kmemleak_warn("kmemleak: Cannot allocate a scan area\n"); goto out; -- Catalin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/