From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757365Ab2EaL4V (ORCPT ); Thu, 31 May 2012 07:56:21 -0400 Received: from mail-we0-f174.google.com ([74.125.82.174]:61277 "EHLO mail-we0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757290Ab2EaL4T (ORCPT ); Thu, 31 May 2012 07:56:19 -0400 Date: Thu, 31 May 2012 14:55:38 +0300 From: Sergey Senozhatsky To: Catalin Marinas Cc: "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" Subject: kmemleak: Message-ID: <20120531115537.GA3676@swordfish.minsk.epam.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, I'm seeing pretty often (may be 10-15 times during last 2 months) kmemleak failed allocation: [ 8213.936237] kmemleak: Kernel memory leak detector disabled [ 8214.660454] kmemleak: Automatic memory scanning thread ended I've a patch that gives a bit more info on last kmemleak step (for example): [ 8213.935927] kmemleak: Cannot allocate a kmemleak_object structure [ 8213.935950] kmemleak: size: 192, mask: 70144 [ 8213.935955] Pid: 444, comm: kswapd0 Not tainted 3.5.0-rc0-dbg-10118-gaf992ce-dirty #1152 [ 8213.935957] Call Trace: [ 8213.935986] [] create_object+0x7d/0x305 [ 8213.936009] [] ? mempool_alloc_slab+0x15/0x17 [ 8213.936014] [] ? mempool_alloc_slab+0x15/0x17 [ 8213.936020] [] kmemleak_alloc+0x26/0x43 [ 8213.936041] [] kmem_cache_alloc+0xd7/0x1e6 [ 8213.936046] [] mempool_alloc_slab+0x15/0x17 [ 8213.936050] [] mempool_alloc+0x81/0x146 [ 8213.936074] [] ? do_raw_spin_lock+0x69/0xe9 [ 8213.936079] [] bio_alloc_bioset+0x33/0xc4 [ 8213.936085] [] ? get_swap_bio+0x79/0x79 [ 8213.936089] [] bio_alloc+0x15/0x24 [ 8213.936109] [] get_swap_bio+0x1f/0x79 [ 8213.936114] [] swap_writepage+0x3d/0x9f [ 8213.936120] [] pageout.isra.48+0x127/0x2f9 [ 8213.936141] [] shrink_inactive_list+0x4eb/0x94f [ 8213.936146] [] shrink_lruvec+0x33c/0x46f [ 8213.936151] [] kswapd+0x680/0xa58 [ 8213.936172] [] ? try_to_free_pages+0x27f/0x27f [ 8213.936178] [] kthread+0x8b/0x93 [ 8213.936184] [] kernel_thread_helper+0x4/0x10 [ 8213.936207] [] ? retint_restore_args+0x13/0x13 [ 8213.936211] [] ? __init_kthread_worker+0x5a/0x5a [ 8213.936215] [] ? gs_change+0x13/0x13 The question is - could it be of any use to printk stack trace with function parameters (size, flag) for failed allocation? If so, I'll prepare a proper patch. Signed-off-by: Sergey Senozhatsky --- mm/kmemleak.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 45eb621..60c49a5 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -521,8 +521,10 @@ static struct kmemleak_object *create_object(unsigned long ptr, size_t size, object = kmem_cache_alloc(object_cache, gfp_kmemleak_mask(gfp)); if (!object) { + write_lock_irqsave(&kmemleak_lock, flags); pr_warning("Cannot allocate a kmemleak_object structure\n"); - kmemleak_disable(); + kmemleak_stop("size: %zu, mask: %u\n", size, gfp_kmemleak_mask(gfp)); + write_unlock_irqrestore(&kmemleak_lock, flags); return NULL; }