Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755950Ab3EOCuR (ORCPT ); Tue, 14 May 2013 22:50:17 -0400 Received: from mail-ie0-f178.google.com ([209.85.223.178]:33714 "EHLO mail-ie0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752338Ab3EOCuP (ORCPT ); Tue, 14 May 2013 22:50:15 -0400 MIME-Version: 1.0 In-Reply-To: <20130514221748.6180.30597.stgit@ahduyck-cp1.jf.intel.com> References: <20130514221748.6180.30597.stgit@ahduyck-cp1.jf.intel.com> Date: Tue, 14 May 2013 19:50:14 -0700 X-Google-Sender-Auth: nvuG-nU8sG5QdUgJFMWyMSzLb-c Message-ID: Subject: Re: [PATCH] pci: Avoid reentrant calls to work_on_cpu From: Yinghai Lu To: Alexander Duyck Cc: Bjorn Helgaas , Gu Zheng , "linux-pci@vger.kernel.org" , Linux Kernel Mailing List , NetDev Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2464 Lines: 59 On Tue, May 14, 2013 at 3:26 PM, Alexander Duyck wrote: > This change is meant to fix a deadlock seen when pci_enable_sriov was > called from within a driver's probe routine. The issue was that > work_on_cpu calls flush_work which attempts to flush a work queue for a > cpu that we are currently working in. In order to avoid the reentrant > path we just skip the call to work_on_cpu in the case that the device > node matches our current node. > > Reported-by: Yinghai Lu > Signed-off-by: Alexander Duyck > --- > > This patch is meant to address the issue pointed out in an earlier patch > sent by Yinghai Lu titled: > [PATCH 6/7] PCI: Make sure VF's driver get attached after PF's Yes, that help. my v2 patch will not need to device schecdule and device_initicall to wait first work_on_cpu is done. Tested-by: Yinghai Lu > > drivers/pci/pci-driver.c | 14 +++++++++----- > 1 files changed, 9 insertions(+), 5 deletions(-) > > diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c > index 79277fb..caeb1c0 100644 > --- a/drivers/pci/pci-driver.c > +++ b/drivers/pci/pci-driver.c > @@ -277,12 +277,16 @@ static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev, > int error, node; > struct drv_dev_and_id ddi = { drv, dev, id }; > > - /* Execute driver initialization on node where the device's > - bus is attached to. This way the driver likely allocates > - its local memory on the right node without any need to > - change it. */ > + /* > + * Execute driver initialization on the node where the device's > + * bus is attached. This way the driver likely allocates > + * its local memory on the right node without any need to > + * change it. If the node is the current node just call > + * local_pci_probe and avoid the possibility of reentrant > + * calls to work_on_cpu. > + */ > node = dev_to_node(&dev->dev); > - if (node >= 0) { > + if ((node >= 0) && (node != numa_node_id())) { > int cpu; > > get_online_cpus(); > -- 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/