From patchwork Wed Aug 22 07:49:08 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Feng Tang X-Patchwork-Id: 1360111 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id 1B6CADFF0F for ; Wed, 22 Aug 2012 07:54:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758637Ab2HVHyq (ORCPT ); Wed, 22 Aug 2012 03:54:46 -0400 Received: from mga11.intel.com ([192.55.52.93]:52720 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758468Ab2HVHyi (ORCPT ); Wed, 22 Aug 2012 03:54:38 -0400 Received: from azsmga002.ch.intel.com ([10.2.17.35]) by fmsmga102.fm.intel.com with ESMTP; 22 Aug 2012 00:54:37 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.77,808,1336374000"; d="scan'208";a="136745154" Received: from feng-i7.sh.intel.com (HELO feng-i7) ([10.239.14.125]) by AZSMGA002.ch.intel.com with ESMTP; 22 Aug 2012 00:54:35 -0700 Date: Wed, 22 Aug 2012 15:49:08 +0800 From: Feng Tang To: Fengguang Wu Cc: "Paul E. McKenney" , Steven Rostedt , Avi Kivity , Steven Rostedt , LKML , "kvm@vger.kernel.org" , Kenji Kaneshige , Yinghai Lu , Bjorn Helgaas , Subject: Re: pci_get_subsys: GFP_KERNEL allocations with IRQs disabled Message-ID: <20120822154908.2e6ef3c0@feng-i7> In-Reply-To: <20120822025008.GA8066@localhost> References: <5017D19B.5080806@redhat.com> <1343738627.27983.30.camel@gandalf.stny.rr.com> <5017D4AB.3090107@redhat.com> <1343740419.27983.33.camel@gandalf.stny.rr.com> <20120731234336.GA5526@localhost> <1343778699.27983.70.camel@gandalf.stny.rr.com> <20120731235705.GW2422@linux.vnet.ibm.com> <1343779778.27983.73.camel@gandalf.stny.rr.com> <20120801001811.GX2422@linux.vnet.ibm.com> <20120801004319.GA7043@localhost> <20120822025008.GA8066@localhost> Organization: intel X-Mailer: Claws Mail 3.7.6 (GTK+ 2.22.0; i486-pc-linux-gnu) Mime-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Hi Fengguang, On Wed, 22 Aug 2012 10:50:08 +0800 Fengguang Wu wrote: > Feng, > > > I think it's pci_get_subsys() triggered this assert: > > > > /* > > * Oi! Can't be having __GFP_FS allocations with IRQs disabled. > > */ > > if (DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags))) > > return; > > It's bisected down to this commit: > > commit 55c844a4dd16a4d1fdc0cf2a283ec631a02ec448 > Author: Feng Tang > AuthorDate: Wed May 30 23:15:41 2012 +0800 > Commit: Ingo Molnar > CommitDate: Wed Jun 6 12:03:23 2012 +0200 > > x86/reboot: Fix a warning message triggered by stop_other_cpus() > > Thanks, > Fengguang Thanks for the bisection. Revert my commit should be a solution, but can we simply make the pci_device_id a local on stack one instead of using sleepable kmalloc for it, as this sounds fragile when pci_get_subsys get called in a late system reboot stage? Thanks, Feng ------------ > > > [ 91.282131] machine restart > > [ 91.283895] ------------[ cut here ]------------ > > [ 91.284731] WARNING: at /c/wfg/linux/kernel/lockdep.c:2739 lockdep_trace_alloc+0x1fb/0x210() > > [ 91.286132] Modules linked in: > > [ 91.286703] Pid: 697, comm: reboot Not tainted 3.5.0-00024-g01ff5db-dirty #4 > > [ 91.287859] Call Trace: > > [ 91.288289] [<81050148>] warn_slowpath_common+0xb8/0x100 > > [ 91.289338] [<8110acdb>] ? lockdep_trace_alloc+0x1fb/0x210 > > [ 91.290264] [<8110acdb>] ? lockdep_trace_alloc+0x1fb/0x210 > > [ 91.291161] [<810501ce>] warn_slowpath_null+0x3e/0x50 > > [ 91.292042] [<8110acdb>] lockdep_trace_alloc+0x1fb/0x210 > > [ 91.292934] [<81228e25>] kmem_cache_alloc_trace+0x55/0x600 > > [ 91.292934] [<813025ca>] ? kobject_put+0x9a/0x160 > > [ 91.292934] [<814e95e0>] ? klist_iter_exit+0x30/0x50 > > [ 91.292934] [<81405881>] ? bus_find_device+0xf1/0x120 > > [ 91.292934] [<81361a3c>] ? pci_get_subsys+0x11c/0x1b0 > > [ 91.292934] [<81361a3c>] pci_get_subsys+0x11c/0x1b0 > > [ 91.292934] [<81361afe>] pci_get_device+0x2e/0x40 > > [ 91.292934] [<81033e25>] mach_reboot_fixups+0xa5/0xd0 > > [ 91.292934] [<81027611>] native_machine_emergency_restart+0x1f1/0x590 > > [ 91.292934] [<814f2e00>] ? printk+0x4b/0x5b > > [ 91.292934] [<810269ef>] native_machine_restart+0x6f/0x80 > > [ 91.292934] [<810271cc>] machine_restart+0x1c/0x30 > > [ 91.292934] [<810886e0>] kernel_restart+0x70/0xc0 > > [ 91.292934] [<81088a85>] sys_reboot+0x325/0x380 > > [ 91.292934] [<811f796c>] ? handle_pte_fault+0xdc/0x1740 > > [ 91.292934] [<811f93e7>] ? handle_mm_fault+0x417/0x4a0 > > [ 91.292934] [<8103e07b>] ? do_page_fault+0x7fb/0xb30 > > [ 91.292934] [<810b33e7>] ? up_read+0x37/0x70 > > [ 91.292934] [<8103e07b>] ? do_page_fault+0x7fb/0xb30 > > [ 91.292934] [<8123c063>] ? do_sys_open+0x3a3/0x3f0 > > [ 91.292934] [<8123c063>] ? do_sys_open+0x3a3/0x3f0 > > [ 91.292934] [<810b0270>] ? update_rmtp+0xe0/0xe0 > > [ 91.292934] [<8150376e>] ? restore_all+0xf/0xf > > [ 91.292934] [<8103d880>] ? vmalloc_sync_all+0x320/0x320 > > [ 91.292934] [<81109fca>] ? trace_hardirqs_on_caller+0x28a/0x380 > > [ 91.292934] [<81311594>] ? trace_hardirqs_on_thunk+0xc/0x10 > > [ 91.292934] [<81503735>] syscall_call+0x7/0xb > > > > Thanks, > > Fengguang Reviewed-by: Fengguang Wu --- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/drivers/pci/search.c b/drivers/pci/search.c index 993d4a0..e5ccede 100644 --- a/drivers/pci/search.c +++ b/drivers/pci/search.c @@ -246,7 +246,7 @@ struct pci_dev *pci_get_subsys(unsigned int vendor, unsigned int device, struct pci_dev *from) { struct pci_dev *pdev; - struct pci_device_id *id; + struct pci_device_id id; /* * pci_find_subsys() can be called on the ide_setup() path, @@ -257,17 +257,12 @@ struct pci_dev *pci_get_subsys(unsigned int vendor, unsigned int device, if (unlikely(no_pci_devices())) return NULL; - id = kzalloc(sizeof(*id), GFP_KERNEL); - if (!id) - return NULL; - id->vendor = vendor; - id->device = device; - id->subvendor = ss_vendor; - id->subdevice = ss_device; - - pdev = pci_get_dev_by_id(id, from); - kfree(id); + id.vendor = vendor; + id.device = device; + id.subvendor = ss_vendor; + id.subdevice = ss_device; + pdev = pci_get_dev_by_id(&id, from); return pdev; }