From patchwork Mon Nov 26 16:34:37 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Dumazet X-Patchwork-Id: 201725 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 [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id B55522C0079 for ; Tue, 27 Nov 2012 03:34:43 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753945Ab2KZQel (ORCPT ); Mon, 26 Nov 2012 11:34:41 -0500 Received: from mail-pb0-f46.google.com ([209.85.160.46]:39005 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754011Ab2KZQek (ORCPT ); Mon, 26 Nov 2012 11:34:40 -0500 Received: by mail-pb0-f46.google.com with SMTP id wy7so8138864pbc.19 for ; Mon, 26 Nov 2012 08:34:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=subject:from:to:cc:in-reply-to:references:content-type:date :message-id:mime-version:x-mailer:content-transfer-encoding; bh=rfPofKpDmgziaO9f72I3uTWewcVuzYjRUchA+237T4o=; b=CiDNMhSAZhqJ4iT47ZgRo43dO04wnI+NHE4505b8JlIXgLnSI4Vmuh0T5bA6GH/bM6 GLPlk8WB4xsojbuDWxshaxqgo2DCtWg5cRAL6lJZEexPE1Avq8JR7qf+5Klz1Ri0rr5X KR5KaydnF4D0B76svvh3nUnEzcp1zop7AvT+ziwq7x1RfTqCAKuF3PX7p9g1wkSuXgVk 804PHdPbfPimvfe8NottvwrFv4JUaWjR6QalkwlifkYvCdRLdfEedBHLhHmmHAqJIDZp RH0OdxiSoDzuF41z1DK0s5lk1wkyhoXHyorPiQRKhTo6ujEli9fgsHI+wpBVCjPnAzgg 3dsQ== Received: by 10.66.87.167 with SMTP id az7mr34133674pab.69.1353947680120; Mon, 26 Nov 2012 08:34:40 -0800 (PST) Received: from [172.19.240.142] ([172.19.240.142]) by mx.google.com with ESMTPS id i4sm9014605pav.20.2012.11.26.08.34.38 (version=SSLv3 cipher=OTHER); Mon, 26 Nov 2012 08:34:39 -0800 (PST) Subject: Re: BQL support in gianfar causes network hickup From: Eric Dumazet To: Tino Keitel Cc: Paul Gortmaker , netdev@vger.kernel.org, "Keitel, Tino (ALC NetworX GmbH)" In-Reply-To: <20121126100111.GA3728@mac.home> References: <9AA65D849A88EB44B5D9B6A8BA098E23040A60D6EE6E@Exchange1.lawo.de> <50AFA599.9040108@windriver.com> <1353800616.2590.4562.camel@edumazet-glaptop> <20121126100111.GA3728@mac.home> Date: Mon, 26 Nov 2012 08:34:37 -0800 Message-ID: <1353947677.7553.2.camel@edumazet-glaptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, 2012-11-26 at 11:01 +0100, Tino Keitel wrote: > On Sat, Nov 24, 2012 at 15:43:36 -0800, Eric Dumazet wrote: > > [...] > > > Hmm, I wonder if BQL makes a particular bug showing more often. > > > > I see gianfar uses a very small watchdog_timeo of 1 second, while many > > drivers use 5 seconds. > > > > What happens if you change this to 5 seconds ? > > I still got the trace and a failing ptp client. > Thanks. Is this bug easy to trigger ? I suspect a core issue and a race, likely to happen on your (non x86) hardware Could you add the following debugging patch ? --- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index aefc150..a8859ec 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -117,7 +117,7 @@ int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q, int ret = NETDEV_TX_BUSY; /* And release qdisc */ - spin_unlock(root_lock); +// spin_unlock(root_lock); HARD_TX_LOCK(dev, txq, smp_processor_id()); if (!netif_xmit_frozen_or_stopped(txq)) @@ -125,7 +125,7 @@ int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q, HARD_TX_UNLOCK(dev, txq); - spin_lock(root_lock); +// spin_lock(root_lock); if (dev_xmit_complete(ret)) { /* Driver sent out skb successfully or skb was consumed */