From patchwork Wed Jan 9 20:25:03 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: William Tu X-Patchwork-Id: 1022619 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=openvswitch.org (client-ip=140.211.169.12; helo=mail.linuxfoundation.org; envelope-from=ovs-dev-bounces@openvswitch.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="XcnuDRNq"; dkim-atps=neutral Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 43Zgcv2Pgrz9s7T for ; Thu, 10 Jan 2019 07:26:07 +1100 (AEDT) Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id F28E3C97; Wed, 9 Jan 2019 20:26:03 +0000 (UTC) X-Original-To: dev@openvswitch.org Delivered-To: ovs-dev@mail.linuxfoundation.org Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 44BB3B79 for ; Wed, 9 Jan 2019 20:26:02 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-pf1-f194.google.com (mail-pf1-f194.google.com [209.85.210.194]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 026B776A for ; Wed, 9 Jan 2019 20:26:01 +0000 (UTC) Received: by mail-pf1-f194.google.com with SMTP id q1so4190818pfi.5 for ; Wed, 09 Jan 2019 12:26:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=VFdDhPRDKPtCiMsD3HxaP1UWvh/wwGDziw3x6023uQc=; b=XcnuDRNqcVUncFlCLP37tOuEHedg4vYli7cxpqavLY47Rs069fczSF52YBpJyTxv2W gR7kyDa7glypX/p65LJAXFn4QfSIAUXmUwTFJbWtIIpCvX6A0uzqhahm6Ywkh/sD2/j0 a2Pbbq+ygMKw+kdS6YWIKAS4JCbU3NVd0j+JYc1vakFUbhJ53HHKTg/wVVJjx8OSxw95 HwAGxl9JlzufhictlUwkkoSWPqSchMsNPoKMdbPjw5sYJZM1G77G9MYf3bHi2XOV2TcM FV5jXGbhcrZB1bGSxWXQ2Qonc5JNwmoc24WmpO8oSMv2R8xVP9un83LH3RyYo/ZOeTob UO/Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=VFdDhPRDKPtCiMsD3HxaP1UWvh/wwGDziw3x6023uQc=; b=e4xDr53TVu+tqIfQkvZJBRvk4EORWvclBWDKhOu3H/DwNgzYAFDpoykjkz8T197LnG 3nuuj09gQkTFCeS3sAPHQsh3JqqjRWqMMs6onZC0oGrHc21MrZikHXJyTUyeyYfQdb4Y 4FZnytQ2SKHcQFQrEeQyuDA2IXevXElrSkOSYGzGfz8AMKdO6D1ETm7b4LaGE8zVXorS Vutmh+3YS6MTXqgEtGwjfNPuzZkNPGdJ3AEKR8P8d6b3pbSHj3l8ZJx4BR7gT5nYRn+K AH2WP0k/ppsq/GCVeWGA6MeXO7jE0L0TsBFneQvEGlvZtgUf6aJOsY/u1MtCcN73fWMk Ne9g== X-Gm-Message-State: AJcUukd87QzU7XKlfjMpBdQ61MV628S6bZlSCDs66NjGkqjpraD8F9hN GN0yB6b6DMo9QbO6KheEsoHIzTZ5 X-Google-Smtp-Source: ALg8bN5Rcckjr3Sixu7yR3f1KjN8HXbC3bJP3YMZq0JWgo/kTcmBDp0E1ABIzewsLTkQd4JDmK7H7Q== X-Received: by 2002:a63:235f:: with SMTP id u31mr4512722pgm.122.1547065561174; Wed, 09 Jan 2019 12:26:01 -0800 (PST) Received: from sc9-mailhost3.vmware.com ([66.170.99.1]) by smtp.gmail.com with ESMTPSA id c7sm103783969pfa.24.2019.01.09.12.26.00 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 09 Jan 2019 12:26:00 -0800 (PST) From: William Tu To: dev@openvswitch.org Date: Wed, 9 Jan 2019 12:25:03 -0800 Message-Id: <1547065503-6250-1-git-send-email-u9012063@gmail.com> X-Mailer: git-send-email 2.7.4 X-Spam-Status: No, score=-1.7 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_ENVFROM_END_DIGIT,FREEMAIL_FROM, RCVD_IN_DNSWL_NONE autolearn=no version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Subject: [ovs-dev] [PATCHv2] faq: unload kernel module when non-zero refcnt. X-BeenThere: ovs-dev@openvswitch.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: ovs-dev-bounces@openvswitch.org Errors-To: ovs-dev-bounces@openvswitch.org Describe the issue about reference count and how to drop it and unload the kernel module. Signed-off-by: William Tu Cc: Greg Rose --- Documentation/faq/issues.rst | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/Documentation/faq/issues.rst b/Documentation/faq/issues.rst index 8a30dad37da0..70bcb12cdaf1 100644 --- a/Documentation/faq/issues.rst +++ b/Documentation/faq/issues.rst @@ -419,3 +419,17 @@ Q: I just upgraded and I see a performance drop. Why? To get the best possible performance and functionality, it is recommended to pair the same versions of the kernel module and OVS userspace. + +Q: I can't unload the openvswitch kernel module. Why? + + A: The userspace might still hold the reference count. + So ``rmmod openvswitch`` does not work, for example:: + + $ lsmod | grep openvswitch + openvswitch 155648 4 + nf_conncount 24576 1 openvswitch + + Use the command below to drop the refcnt:: + + $ ovs-dpctl del-dp system@ovs-system + $ rmmod openvswitch