From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932170AbWGCWuW (ORCPT ); Mon, 3 Jul 2006 18:50:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932171AbWGCWuW (ORCPT ); Mon, 3 Jul 2006 18:50:22 -0400 Received: from tetsuo.zabbo.net ([207.173.201.20]:56796 "EHLO tetsuo.zabbo.net") by vger.kernel.org with ESMTP id S932170AbWGCWuU (ORCPT ); Mon, 3 Jul 2006 18:50:20 -0400 From: Zach Brown To: Arjan van de Ven , Andrew Morton , linux-kernel@vger.kernel.org, openib-general@openib.org Message-Id: <20060703225019.7379.96075.sendpatchset@tetsuo.zabbo.net> Subject: [PATCH] mthca: initialize send and receive queue locks separately Date: Mon, 3 Jul 2006 15:50:20 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org mthca: initialize send and receive queue locks separately lockdep identifies a lock by the call site of its initialization. By initializing the send and receive queue locks in mthca_wq_init() we confuse lockdep. It warns that that the ordered acquiry of both locks in mthca_modify_qp() is recursive acquiry of one lock: ============================================= [ INFO: possible recursive locking detected ] --------------------------------------------- modprobe/1192 is trying to acquire lock: (&wq->lock){....}, at: [] mthca_modify_qp+0x60/0xa7b [ib_mthca] but task is already holding lock: (&wq->lock){....}, at: [] mthca_modify_qp+0x53/0xa7b [ib_mthca] Initializing the locks separately in mthca_alloc_qp_common() stops the warning and will let lockdep enforce proper ordering on paths that acquire both locks. Signed-off-by: Zach Brown --- drivers/infiniband/hw/mthca/mthca_qp.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) Index: 2.6.17-mm6/drivers/infiniband/hw/mthca/mthca_qp.c =================================================================== --- 2.6.17-mm6.orig/drivers/infiniband/hw/mthca/mthca_qp.c 2006-07-03 08:41:16.000000000 -0400 +++ 2.6.17-mm6/drivers/infiniband/hw/mthca/mthca_qp.c 2006-07-03 10:05:52.000000000 -0400 @@ -224,7 +224,7 @@ static void mthca_wq_init(struct mthca_wq *wq) { - spin_lock_init(&wq->lock); + /* mthca_alloc_qp_common() initializes the locks */ wq->next_ind = 0; wq->last_comp = wq->max - 1; wq->head = 0; @@ -1114,6 +1114,9 @@ qp->sq_policy = send_policy; mthca_wq_init(&qp->sq); mthca_wq_init(&qp->rq); + /* these are initialized separately so lockdep can tell them apart */ + spin_lock_init(&qp->sq.lock); + spin_lock_init(&qp->rq.lock); ret = mthca_map_memfree(dev, qp); if (ret)