From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by dpdk.org (Postfix) with ESMTP id CF63F1B3F2 for ; Mon, 29 Jan 2018 10:37:50 +0100 (CET) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 29 Jan 2018 01:37:49 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.46,429,1511856000"; d="scan'208";a="26267972" Received: from aburakov-mobl.ger.corp.intel.com (HELO [10.237.220.145]) ([10.237.220.145]) by fmsmga001.fm.intel.com with ESMTP; 29 Jan 2018 01:37:48 -0800 To: "Tan, Jianfeng" , "dev@dpdk.org" Cc: "Richardson, Bruce" , "Ananyev, Konstantin" , "thomas@monjalon.net" References: <1512067450-59203-1-git-send-email-jianfeng.tan@intel.com> <1516938082-27852-1-git-send-email-jianfeng.tan@intel.com> <1516938082-27852-2-git-send-email-jianfeng.tan@intel.com> From: "Burakov, Anatoly" Message-ID: <55668e61-c44f-82c2-ccf0-f83cb04b8e78@intel.com> Date: Mon, 29 Jan 2018 09:37:47 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.5.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH v6 1/2] eal: add channel for multi-process communication X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 29 Jan 2018 09:37:51 -0000 On 29-Jan-18 6:37 AM, Tan, Jianfeng wrote: > Hi Anatoly, > >> -----Original Message----- >> From: Burakov, Anatoly >> Sent: Friday, January 26, 2018 6:26 PM >> To: Tan, Jianfeng; dev@dpdk.org >> Cc: Richardson, Bruce; Ananyev, Konstantin; thomas@monjalon.net >> Subject: Re: [PATCH v6 1/2] eal: add channel for multi-process >> communication >> >> On 26-Jan-18 3:41 AM, Jianfeng Tan wrote: >>> Previouly, there are three channels for multi-process >>> (i.e., primary/secondary) communication. >>> 1. Config-file based channel, in which, the primary process writes >>> info into a pre-defined config file, and the secondary process >>> reads the info out. >>> 2. vfio submodule has its own channel based on unix socket for the >>> secondary process to get container fd and group fd from the >>> primary process. >>> 3. pdump submodule also has its own channel based on unix socket for >>> packet dump. >>> >>> It'd be good to have a generic communication channel for multi-process >>> communication to accommodate the requirements including: >>> a. Secondary wants to send info to primary, for example, secondary >>> would like to send request (about some specific vdev to primary). >>> b. Sending info at any time, instead of just initialization time. >>> c. Share FDs with the other side, for vdev like vhost, related FDs >>> (memory region, kick) should be shared. >>> d. A send message request needs the other side to response immediately. >>> >>> This patch proposes to create a communication channel, based on >> datagram >>> unix socket, for above requirements. Each process will block on a unix >>> socket waiting for messages from the peers. >>> >>> Three new APIs are added: >>> >>> 1. rte_eal_mp_action_register() is used to register an action, >>> indexed by a string, when a component at receiver side would like >>> to response the messages from the peer processe. >>> 2. rte_eal_mp_action_unregister() is used to unregister the action >>> if the calling component does not want to response the messages. >>> 3. rte_eal_mp_sendmsg() is used to send a message, and returns >>> immediately. If there are n secondary processes, the primary >>> process will send n messages. >>> >>> Suggested-by: Konstantin Ananyev >>> Signed-off-by: Jianfeng Tan >>> Reviewed-by: Anatoly Burakov >>> Acked-by: Konstantin Ananyev >>> --- >>> + } >>> + closedir(mp_dir); >>> + >>> + return ret; >> >> Nitpick: you probably don't need ret here, just return 0 as in other places. > > We cannot just return 0 as it could be -1 as above comment shows. > The ret variable was introduced to avoid two "closedir()". > > Thanks, > Jianfeng > Yep you're right, apologies. -- Thanks, Anatoly