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=-7.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 1969DC5519F for ; Wed, 25 Nov 2020 06:20:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AB0012173E for ; Wed, 25 Nov 2020 06:20:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="TADp4mel" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726518AbgKYGUe (ORCPT ); Wed, 25 Nov 2020 01:20:34 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:21154 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725838AbgKYGUe (ORCPT ); Wed, 25 Nov 2020 01:20:34 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1606285233; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=hzf8L+pJkmJC6kuPctTHWalVfjiH6jJR7fCpq2GAvzk=; b=TADp4melm1A32Mr2mey/51KceMl6SVCZiMupcyEDf2j0h2DFKpf+4f8EAdelrL9nMm4wlC ctJ3yB8agvPXCZ63nLJxlLbrUaYgkrp0+VHNk2YilFvqRgXMf/g9mhh2c/l2CwhCUCtq36 dyPBGjGg4Q6BI81Tt2HMVsUmxnxEsXA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-542-s7V2aL5HN0Sj_o7CAHGE0w-1; Wed, 25 Nov 2020 01:20:28 -0500 X-MC-Unique: s7V2aL5HN0Sj_o7CAHGE0w-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id DCB6F8144E5; Wed, 25 Nov 2020 06:20:26 +0000 (UTC) Received: from [10.72.13.165] (ovpn-13-165.pek2.redhat.com [10.72.13.165]) by smtp.corp.redhat.com (Postfix) with ESMTP id 940005D9C0; Wed, 25 Nov 2020 06:20:19 +0000 (UTC) Subject: Re: netconsole deadlock with virtnet To: Steven Rostedt Cc: Jakub Kicinski , Leon Romanovsky , Sergey Senozhatsky , "Michael S. Tsirkin" , Petr Mladek , John Ogness , virtualization@lists.linux-foundation.org, Amit Shah , Itay Aveksis , Ran Rozenstein , netdev References: <20201117102341.GR47002@unreal> <20201117093325.78f1486d@gandalf.local.home> <93b42091-66f2-bb92-6822-473167b2698d@redhat.com> <20201118091257.2ee6757a@gandalf.local.home> <20201123110855.GD3159@unreal> <20201123093128.701cf81b@gandalf.local.home> <20201123105252.1c295138@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <20201123140934.38748be3@gandalf.local.home> <20201123112130.759b9487@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <1133f1a4-6772-8aa3-41dd-edbc1ee76cee@redhat.com> <20201124093137.48d1e603@gandalf.local.home> From: Jason Wang Message-ID: Date: Wed, 25 Nov 2020 14:20:17 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201124093137.48d1e603@gandalf.local.home> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2020/11/24 下午10:31, Steven Rostedt wrote: > On Tue, 24 Nov 2020 11:22:03 +0800 > Jason Wang wrote: > >> Btw, have a quick search, there are several other drivers that uses tx >> lock in the tx NAPI. > tx NAPI is not the issue. The issue is that write_msg() (in netconsole.c) > calls this polling logic with the target_list_lock held. But in the tx NAPI poll it tries to lock TX instead of using trylock. > > Are those other drivers called by netconsole? If not, then this is unique > to virtio-net. I think the answer is yes, since net console is not disabled in the codes. Thanks > > -- Steve >