From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7CB05C43331 for ; Fri, 3 Apr 2020 04:40:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4410A208E4 for ; Fri, 3 Apr 2020 04:40:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585888810; bh=MA774hbNnMi8WdldEMlM4hLd52sDWJQ+AHnAQqVzUF0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=IWB9g0SzR1xGHccAuUjs8MgR3qHglXDn2wqENX8WGXq+9mPCIOZ78tbaHv1XqV3uV 04kTFtGizcMiD/izfgDn8+px+TxS2oIL+jb0mv9m/UxSB0HvINtLrJ1GHoXOzRRU9m IViwt5uAjNOdj34HrZFYK1VXEoTivHCA0DAppec4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730219AbgDCEkJ (ORCPT ); Fri, 3 Apr 2020 00:40:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:42170 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725851AbgDCEkJ (ORCPT ); Fri, 3 Apr 2020 00:40:09 -0400 Received: from localhost (unknown [213.57.247.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 22CA22063A; Fri, 3 Apr 2020 04:40:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585888808; bh=MA774hbNnMi8WdldEMlM4hLd52sDWJQ+AHnAQqVzUF0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=cV85XdIZsxoxqQhT8g5rNSJiaN3iNosjbBnL8tjYcp1e3qqEqcQaB+IelmuCuXbfJ yNx0GuIsoBsdXsOrvdGKzRco00L2n59FCUpXW9RomtVz8pyNaN+YW+TsKDxhoJ4dab JUD1gAqCVAPvfffoZO9/HDxQoBTrwno1nQYzt56U= Date: Fri, 3 Apr 2020 07:40:05 +0300 From: Leon Romanovsky To: David Miller Cc: kuba@kernel.org, arjan@linux.intel.com, xiyou.wangcong@gmail.com, jhs@mojatatu.com, jiri@resnulli.us, netdev@vger.kernel.org, itayav@mellanox.com Subject: Re: [PATCH net] net/sched: Don't print dump stack in event of transmission timeout Message-ID: <20200403044005.GD80989@unreal> References: <20200402152336.538433-1-leon@kernel.org> <20200402.180218.940555077368617365.davem@davemloft.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200402.180218.940555077368617365.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, Apr 02, 2020 at 06:02:18PM -0700, David Miller wrote: > From: Leon Romanovsky > Date: Thu, 2 Apr 2020 18:23:36 +0300 > > > In event of transmission timeout, the drivers are given an opportunity > > to recover and continue to work after some in-house cleanups. > > > > Such event can be caused by HW bugs, wrong congestion configurations > > and many more other scenarios. In such case, users are interested to > > get a simple "NETDEV WATCHDOG ... " print, which points to the relevant > > netdevice in trouble. > > > > The dump stack printed later was added in the commit b4192bbd85d2 > > ("net: Add a WARN_ON_ONCE() to the transmit timeout function") to give > > extra information, like list of the modules and which driver is involved. > > > > While the latter is already printed in "NETDEV WATCHDOG ... ", the list > > of modules rarely needed and can be collected later. > > > > So let's remove the WARN_ONCE() and make dmesg look more user-friendly in > > large cluster setups. > > Software bugs play into these situations and on at least two or three > occasions I know that the backtrace hinted at the cause of the bug. > > I'm not applying this, sorry. Dave, In our case, it is HW bug and I'm looking for a way to silence dump stack. Do I have any way to avoid WARN here? It will be a little bit overkill to add some special flag to general netdev structure just to mark that mlx4 doesn't need this trace. Thanks