Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933764AbaFSQw4 (ORCPT ); Thu, 19 Jun 2014 12:52:56 -0400 Received: from e31.co.us.ibm.com ([32.97.110.149]:60997 "EHLO e31.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932775AbaFSQwz (ORCPT ); Thu, 19 Jun 2014 12:52:55 -0400 Date: Thu, 19 Jun 2014 09:52:47 -0700 From: "Paul E. McKenney" To: Christoph Lameter Cc: Sasha Levin , Pekka Enberg , Thomas Gleixner , Matt Mackall , Andrew Morton , Dave Jones , "linux-mm@kvack.org" , LKML Subject: Re: slub/debugobjects: lockup when freeing memory Message-ID: <20140619165247.GA4904@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <53A2F406.4010109@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14061916-8236-0000-0000-000003393AC1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 19, 2014 at 10:03:04AM -0500, Christoph Lameter wrote: > On Thu, 19 Jun 2014, Sasha Levin wrote: > > > [ 690.770137] ? __this_cpu_preempt_check (lib/smp_processor_id.c:63) > > [ 690.770137] __slab_alloc (mm/slub.c:1732 mm/slub.c:2205 mm/slub.c:2369) > > [ 690.770137] ? __lock_acquire (kernel/locking/lockdep.c:3189) > > [ 690.770137] ? __debug_object_init (lib/debugobjects.c:100 lib/debugobjects.c:312) > > [ 690.770137] kmem_cache_alloc (mm/slub.c:2442 mm/slub.c:2484 mm/slub.c:2489) > > [ 690.770137] ? __debug_object_init (lib/debugobjects.c:100 lib/debugobjects.c:312) > > [ 690.770137] ? debug_object_activate (lib/debugobjects.c:439) > > [ 690.770137] __debug_object_init (lib/debugobjects.c:100 lib/debugobjects.c:312) > > [ 690.770137] debug_object_init (lib/debugobjects.c:365) > > [ 690.770137] rcuhead_fixup_activate (kernel/rcu/update.c:231) > > [ 690.770137] debug_object_activate (lib/debugobjects.c:280 lib/debugobjects.c:439) > > [ 690.770137] ? discard_slab (mm/slub.c:1486) > > [ 690.770137] __call_rcu (kernel/rcu/rcu.h:76 (discriminator 2) kernel/rcu/tree.c:2585 (discriminator 2)) > > __call_rcu does a slab allocation? This means __call_rcu can no longer be > used in slab allocators? What happened? My guess is that the root cause is a double call_rcu(), call_rcu_sched(), call_rcu_bh(), or call_srcu(). Perhaps the DEBUG_OBJECTS code now allocates memory to report errors? That would be unfortunate... Thanx, Paul -- 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/