Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758707Ab3ENW30 (ORCPT ); Tue, 14 May 2013 18:29:26 -0400 Received: from mga14.intel.com ([143.182.124.37]:15800 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758537Ab3ENW3Y (ORCPT ); Tue, 14 May 2013 18:29:24 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.87,672,1363158000"; d="scan'208";a="241588324" Subject: [PATCH] pci: Avoid reentrant calls to work_on_cpu To: bhelgaas@google.com, yinghai@kernel.org From: Alexander Duyck Cc: guz.fnst@cn.fujitsu.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Date: Tue, 14 May 2013 15:26:53 -0700 Message-ID: <20130514221748.6180.30597.stgit@ahduyck-cp1.jf.intel.com> User-Agent: StGit/0.16 MIME-Version: 1.0 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: 2005 Lines: 50 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 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/