From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <dev-bounces@dpdk.org> Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 546FDA04B5; Wed, 16 Sep 2020 17:48:30 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 351B71C2FA; Wed, 16 Sep 2020 17:48:30 +0200 (CEST) Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by dpdk.org (Postfix) with ESMTP id 84D2B1C2ED for <dev@dpdk.org>; Wed, 16 Sep 2020 17:48:28 +0200 (CEST) IronPort-SDR: jSP6ultCvMkiZIt/jYzs5CFrvATh8FYCJJbuakzwzoqjGrieYYE2fmR5SxFkeH8FA+M+e8qFwX W8eVkiIXEb/A== X-IronPort-AV: E=McAfee;i="6000,8403,9746"; a="159547007" X-IronPort-AV: E=Sophos;i="5.76,433,1592895600"; d="scan'208";a="159547007" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Sep 2020 08:48:26 -0700 IronPort-SDR: Xr5bQFhi+ilFqcrhp61qNwGw29JCfaBmC1mvGi4Gd19WECThYQhgaXeYJCTt6XuHjjr+wAxvA0 V6D5gZGaQdNg== X-IronPort-AV: E=Sophos;i="5.76,433,1592895600"; d="scan'208";a="483358127" Received: from fyigit-mobl1.ger.corp.intel.com (HELO [10.213.248.202]) ([10.213.248.202]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Sep 2020 08:48:25 -0700 To: wangyunjian <wangyunjian@huawei.com>, "dev@dpdk.org" <dev@dpdk.org> Cc: "thomas@monjalon.net" <thomas@monjalon.net>, "Lilijun (Jerry)" <jerry.lilijun@huawei.com>, xudingke <xudingke@huawei.com> References: <9a94f272bc7c1e5650295ddf3e02fb19b15e7951.1598596042.git.wangyunjian@huawei.com> <daa3327b-1559-c80c-dee4-d6833928af1c@intel.com> <34EFBCA9F01B0748BEB6B629CE643AE60DA4D4A1@DGGEMM533-MBX.china.huawei.com> From: Ferruh Yigit <ferruh.yigit@intel.com> Message-ID: <5b26d986-ffc3-9bac-ed4d-cbc1f0dd342b@intel.com> Date: Wed, 16 Sep 2020 16:48:19 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.2.2 MIME-Version: 1.0 In-Reply-To: <34EFBCA9F01B0748BEB6B629CE643AE60DA4D4A1@DGGEMM533-MBX.china.huawei.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Subject: Re: [dpdk-dev] [PATCH] net/tap: release port upon close X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions <dev.dpdk.org> List-Unsubscribe: <https://mails.dpdk.org/options/dev>, <mailto:dev-request@dpdk.org?subject=unsubscribe> List-Archive: <http://mails.dpdk.org/archives/dev/> List-Post: <mailto:dev@dpdk.org> List-Help: <mailto:dev-request@dpdk.org?subject=help> List-Subscribe: <https://mails.dpdk.org/listinfo/dev>, <mailto:dev-request@dpdk.org?subject=subscribe> Errors-To: dev-bounces@dpdk.org Sender: "dev" <dev-bounces@dpdk.org> On 9/16/2020 8:20 AM, wangyunjian wrote: >> -----Original Message----- >> From: Ferruh Yigit [mailto:ferruh.yigit@intel.com] >> Sent: Tuesday, September 15, 2020 10:53 PM >> To: wangyunjian <wangyunjian@huawei.com>; dev@dpdk.org >> Cc: thomas@monjalon.net; Lilijun (Jerry) <jerry.lilijun@huawei.com>; xudingke >> <xudingke@huawei.com> >> Subject: Re: [dpdk-dev] [PATCH] net/tap: release port upon close >> >> On 8/28/2020 1:37 PM, wangyunjian wrote: >>> From: Yunjian Wang <wangyunjian@huawei.com> >>> >>> Set RTE_ETH_DEV_CLOSE_REMOVE upon probe so all the private resources >>> for the port can be freed by rte_eth_dev_close(). >>> >>> Signed-off-by: Yunjian Wang <wangyunjian@huawei.com> >> >> <...> >> >>> @@ -1040,6 +1044,9 @@ tap_dev_close(struct rte_eth_dev *dev) >>> struct pmd_process_private *process_private = dev->process_private; >>> struct rx_queue *rxq; >>> >>> + if (process_private == NULL) >>> + return; >> >> Why this check is required? > > When user first call 'close()' and later call 'remove()' the tap PMD, in this case, > the tap_dev_close() will be called twice. The second call of tap_dev_close() > shouldn't do any process, we can use this check to return immediately. > When first call is 'close()', it memset the 'eth_dev->data', so the in the later 'remove()' call, 'rte_eth_dev_allocated()' will always return NULL and 'remove()' will exit without calling 'close()'. Also multiple 'close()' calls look safe, because of 'RTE_ETH_VALID_PORTID_OR_RET()' checks is 'rte_eth_dev_close()'. So, as far as I can see this additional check is not needed, but please double check.