From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yh0-f44.google.com (mail-yh0-f44.google.com [209.85.213.44]) by kanga.kvack.org (Postfix) with ESMTP id A30876B0031 for ; Thu, 19 Jun 2014 12:52:55 -0400 (EDT) Received: by mail-yh0-f44.google.com with SMTP id f10so1929549yha.17 for ; Thu, 19 Jun 2014 09:52:55 -0700 (PDT) Received: from e34.co.us.ibm.com (e34.co.us.ibm.com. [32.97.110.152]) by mx.google.com with ESMTPS id h29si8978700yhi.30.2014.06.19.09.52.54 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Thu, 19 Jun 2014 09:52:55 -0700 (PDT) Received: from /spool/local by e34.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 19 Jun 2014 10:52:53 -0600 Received: from b03cxnp08026.gho.boulder.ibm.com (b03cxnp08026.gho.boulder.ibm.com [9.17.130.18]) by d03dlp03.boulder.ibm.com (Postfix) with ESMTP id 4B60519D805E for ; Thu, 19 Jun 2014 10:52:40 -0600 (MDT) Received: from d03av06.boulder.ibm.com (d03av06.boulder.ibm.com [9.17.195.245]) by b03cxnp08026.gho.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id s5JGpjkk4391396 for ; Thu, 19 Jun 2014 18:51:45 +0200 Received: from d03av06.boulder.ibm.com (loopback [127.0.0.1]) by d03av06.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id s5JGuia8001957 for ; Thu, 19 Jun 2014 10:56:44 -0600 Date: Thu, 19 Jun 2014 09:52:47 -0700 From: "Paul E. McKenney" 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: Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Lameter Cc: Sasha Levin , Pekka Enberg , Thomas Gleixner , Matt Mackall , Andrew Morton , Dave Jones , "linux-mm@kvack.org" , LKML 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, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org