Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753599Ab3FJRIY (ORCPT ); Mon, 10 Jun 2013 13:08:24 -0400 Received: from mail-pd0-f176.google.com ([209.85.192.176]:36681 "EHLO mail-pd0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751743Ab3FJRIX (ORCPT ); Mon, 10 Jun 2013 13:08:23 -0400 Message-ID: <51B607FE.3020108@gmail.com> Date: Tue, 11 Jun 2013 01:08:14 +0800 From: Jiang Liu User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130404 Thunderbird/17.0.5 MIME-Version: 1.0 To: Konrad Rzeszutek Wilk CC: Bjorn Helgaas , Yinghai Lu , Jiang Liu , "Rafael J . Wysocki" , Greg Kroah-Hartman , Gu Zheng , Toshi Kani , Myron Stowe , Yijing Wang , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Jeremy Fitzhardinge , xen-devel@lists.xensource.com, virtualization@lists.linux-foundation.org Subject: Re: [RFC PATCH v2, part3 07/11] PCI, xen-pcifront: use new PCI interfaces to simplify implementation References: <1368719459-24800-1-git-send-email-jiang.liu@huawei.com> <1368719459-24800-8-git-send-email-jiang.liu@huawei.com> <20130607145024.GA16631@phenom.dumpdata.com> <20130607153822.GA24882@phenom.dumpdata.com> <51B20F57.7050100@gmail.com> <20130607170706.GB3730@phenom.dumpdata.com> <51B4B266.5010100@gmail.com> <20130610165801.GA24823@phenom.dumpdata.com> In-Reply-To: <20130610165801.GA24823@phenom.dumpdata.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3185 Lines: 74 On Tue 11 Jun 2013 12:58:01 AM CST, Konrad Rzeszutek Wilk wrote: > On Mon, Jun 10, 2013 at 12:50:46AM +0800, Jiang Liu wrote: >> On Sat 08 Jun 2013 01:07:06 AM CST, Konrad Rzeszutek Wilk wrote: >>> On Sat, Jun 08, 2013 at 12:50:31AM +0800, Jiang Liu wrote: >>>> On 06/07/2013 11:38 PM, Konrad Rzeszutek Wilk wrote: >>>>> On Fri, Jun 07, 2013 at 10:50:24AM -0400, Konrad Rzeszutek Wilk wrote: >>>>>> On Thu, May 16, 2013 at 11:50:55PM +0800, Jiang Liu wrote: >>>>>>> Use new PCI interfaces to simplify xen-pcifront implementation: >>>>>>> 1) Use pci_create_root_bus() instead of pci_scan_bus_parented() >>>>>>> because pci_scan_bus_parented() is marked as __deprecated.This >>>>>>> also gets rid of a duplicated call of pci_bus_start_devices(). >>>>>>> 2) Use pci_stop_root_bus() and pci_remove_root_bus() instead of >>>>>>> open-coded private implementation. >>>>>>> 3) Use pci_set_host_bridge_release() to release data structures >>>>>>> associated with PCI root buses. >>>>>>> 4) Use pci_bus_get()/pci_bus_put() to manage PCI root bus reference >>>>>>> count. >>>>>>> >>>>>>> This is also a preparation for coming PCI bus lock enhancement. >>>>> >>>>> With this patch from : >>>>> >>>>> Merge branch 'pci_lock_v3' of https://github.com/jiangliu/linux into testing >>>>> >>>>> >>>>> it blows up when detaching the device. >>>> Hi Konrad, >>>> Thanks for testing! According to the log messages, this issue should >>>> be related to pci bus reference counter management. Seems we have done >>>> an extra(unbalanced) release of pci bus device. >>>> Will investigate it tomorrow! >>> >>> That is quite commendable that you are willing to look over this on >>> the weekend but I am not going to be able to rerun this test until >>> some time in the week. You could enjoy the weekend and just look at >>> this during the week. >> >> Hi Konrad, >> We should have root-caused this bug, which is caused by >> for_each_pci_root_bus(). >> Current implementation doesn't support root bus deletion when walking >> PCI root >> buses by for_each_pci_root_bus(). The reference counter >> (pci_bus->dev.knode_class.n_ref) >> becomes zero after returning from pci_remove_root_bus(), so it triggers >> kref warnings >> and double-free of klist_node object when we call >> pci_get_next_root_bus() to get the >> next PCI root bus. >> So we will first revert to list_for_each_entry_safe(bus, temp, >> &pci_root_buses, node) >> and solve this issue in next version of for_each_pci_root_bus(). > > That definitly solves the issue. Thanks! > > I used pci_lock_v3 of https://github.com/jiangliu/linux and the fix > below. > > Is there a new patchset you are going to be posting or a git branch > that I can look over? > > Thanks. Hi Konrad, Really appreciate your support! I will try to post a new version tomorrow, but I think there won't be big changes except addressing some review comments from you. Thanks! Gerry -- 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/