From patchwork Wed Jan 14 07:44:28 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oliver Hartkopp X-Patchwork-Id: 18393 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by ozlabs.org (Postfix) with ESMTP id 0148CDE107 for ; Wed, 14 Jan 2009 18:44:47 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760243AbZANHob (ORCPT ); Wed, 14 Jan 2009 02:44:31 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760262AbZANHoa (ORCPT ); Wed, 14 Jan 2009 02:44:30 -0500 Received: from mo-p00-ob.rzone.de ([81.169.146.162]:44145 "EHLO mo-p00-ob.rzone.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760243AbZANHo3 (ORCPT ); Wed, 14 Jan 2009 02:44:29 -0500 X-RZG-CLASS-ID: mo00 X-RZG-AUTH: :I2ANY0W6W/eA95XfH/xfO6gOxLxTty/udEMngcJ/VAKW226lDNJVyuUOIDI/VQ== Received: from [192.168.11.14] (p5B22E001.dip.t-dialin.net [91.34.224.1]) by post.strato.de (klopstock mo55) (RZmta 18.10) with ESMTP id y00ff1l0E7Khhh ; Wed, 14 Jan 2009 08:44:26 +0100 (MET) Message-ID: <496D97DC.9020408@hartkopp.net> Date: Wed, 14 Jan 2009 08:44:28 +0100 From: Oliver Hartkopp User-Agent: Mozilla-Thunderbird 2.0.0.19 (X11/20090103) MIME-Version: 1.0 To: David Miller CC: Linux Netdev List Subject: [PATCH 2.6.29] can: fix slowpath issue in hrtimer callback function Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Due to the loopback functionality in can_send() we can not invoke it from hardirq context which was done inside the bcm_tx_timeout_handler() hrtimer callback: [ 700.361154] [] warn_slowpath+0x80/0xb6 [ 700.361163] [] valid_state+0x125/0x136 [ 700.361171] [] mark_lock+0x18e/0x332 [ 700.361180] [] __lock_acquire+0x12e/0xb1e [ 700.361189] [] bcm_tx_timeout_handler+0x0/0xbc [can_bcm] [ 700.361198] [] dev_queue_xmit+0x191/0x479 [ 700.361206] [] __local_bh_disable+0x2b/0x64 [ 700.361213] [] dev_queue_xmit+0x191/0x479 [ 700.361225] [] can_send+0xd7/0x11a [can] [ 700.361235] [] bcm_can_tx+0x9d/0xd9 [can_bcm] [ 700.361245] [] bcm_tx_timeout_handler+0x6a/0xbc [can_bcm] [ 700.361255] [] bcm_tx_timeout_handler+0x0/0xbc [can_bcm] [ 700.361263] [] __run_hrtimer+0x5a/0x86 [ 700.361273] [] bcm_tx_timeout_handler+0x0/0xbc [can_bcm] [ 700.361282] [] hrtimer_interrupt+0xb9/0x110 This patch moves the rest of the functionality from the hrtimer callback to the already existing tasklet to fix this slowpath problem. Signed-off-by: Oliver Hartkopp --- Hello Dave, this patch 'completes' the changes for the hrtimer update of the can-bcm in 2.6.29 :-] Thanks, Oliver diff --git a/net/can/bcm.c b/net/can/bcm.c index 1649c8a..b7c7d46 100644 --- a/net/can/bcm.c +++ b/net/can/bcm.c @@ -347,51 +347,54 @@ static void bcm_tx_timeout_tsklet(unsigned long data) struct bcm_op *op = (struct bcm_op *)data; struct bcm_msg_head msg_head; - /* create notification to user */ - msg_head.opcode = TX_EXPIRED; - msg_head.flags = op->flags; - msg_head.count = op->count; - msg_head.ival1 = op->ival1; - msg_head.ival2 = op->ival2; - msg_head.can_id = op->can_id; - msg_head.nframes = 0; - - bcm_send_to_user(op, &msg_head, NULL, 0); -} - -/* - * bcm_tx_timeout_handler - performes cyclic CAN frame transmissions - */ -static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer) -{ - struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); - enum hrtimer_restart ret = HRTIMER_NORESTART; - if (op->kt_ival1.tv64 && (op->count > 0)) { op->count--; - if (!op->count && (op->flags & TX_COUNTEVT)) - tasklet_schedule(&op->tsklet); + if (!op->count && (op->flags & TX_COUNTEVT)) { + + /* create notification to user */ + msg_head.opcode = TX_EXPIRED; + msg_head.flags = op->flags; + msg_head.count = op->count; + msg_head.ival1 = op->ival1; + msg_head.ival2 = op->ival2; + msg_head.can_id = op->can_id; + msg_head.nframes = 0; + + bcm_send_to_user(op, &msg_head, NULL, 0); + } } if (op->kt_ival1.tv64 && (op->count > 0)) { /* send (next) frame */ bcm_can_tx(op); - hrtimer_forward(hrtimer, ktime_get(), op->kt_ival1); - ret = HRTIMER_RESTART; + hrtimer_start(&op->timer, + ktime_add(ktime_get(), op->kt_ival1), + HRTIMER_MODE_ABS); } else { if (op->kt_ival2.tv64) { /* send (next) frame */ bcm_can_tx(op); - hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2); - ret = HRTIMER_RESTART; + hrtimer_start(&op->timer, + ktime_add(ktime_get(), op->kt_ival2), + HRTIMER_MODE_ABS); } } +} - return ret; +/* + * bcm_tx_timeout_handler - performes cyclic CAN frame transmissions + */ +static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer) +{ + struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); + + tasklet_schedule(&op->tsklet); + + return HRTIMER_NORESTART; } /*