From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by dpdk.org (Postfix) with ESMTP id D2A1D2BF4 for ; Thu, 25 Jan 2018 14:06:01 +0100 (CET) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 25 Jan 2018 05:06:00 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.46,412,1511856000"; d="scan'208";a="26270785" Received: from aburakov-mobl.ger.corp.intel.com (HELO [10.237.220.145]) ([10.237.220.145]) by orsmga001.jf.intel.com with ESMTP; 25 Jan 2018 05:05:58 -0800 To: "Ananyev, Konstantin" , "Tan, Jianfeng" , "dev@dpdk.org" Cc: "Richardson, Bruce" , "thomas@monjalon.net" References: <1512067450-59203-1-git-send-email-jianfeng.tan@intel.com> <1516853783-108023-1-git-send-email-jianfeng.tan@intel.com> <1516853783-108023-3-git-send-email-jianfeng.tan@intel.com> <93ea032e-e2da-f087-567a-2397fad7ff02@intel.com> <2601191342CEEE43887BDE71AB977258862836A2@irsmsx105.ger.corp.intel.com> <2601191342CEEE43887BDE71AB97725886283712@irsmsx105.ger.corp.intel.com> From: "Burakov, Anatoly" Message-ID: Date: Thu, 25 Jan 2018 13:05:57 +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: <2601191342CEEE43887BDE71AB97725886283712@irsmsx105.ger.corp.intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH v3 2/3] eal: add synchronous 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: Thu, 25 Jan 2018 13:06:02 -0000 On 25-Jan-18 1:00 PM, Ananyev, Konstantin wrote: > > >> -----Original Message----- >> From: Burakov, Anatoly >> Sent: Thursday, January 25, 2018 12:26 PM >> To: Ananyev, Konstantin ; Tan, Jianfeng ; dev@dpdk.org >> Cc: Richardson, Bruce ; thomas@monjalon.net >> Subject: Re: [PATCH v3 2/3] eal: add synchronous multi-process communication >> >> On 25-Jan-18 12:19 PM, Ananyev, Konstantin wrote: >>> >>> >>>> -----Original Message----- >>>> From: Burakov, Anatoly >>>> Sent: Thursday, January 25, 2018 12:00 PM >>>> To: Tan, Jianfeng ; dev@dpdk.org >>>> Cc: Richardson, Bruce ; Ananyev, Konstantin ; thomas@monjalon.net >>>> Subject: Re: [PATCH v3 2/3] eal: add synchronous multi-process communication >>>> >>>> On the overall patch, >>>> >>>> Reviewed-by: Anatoly Burakov >>>> >>>> For request(), returning number of replies received actually makes >>>> sense, because now we get use the value to read our replies, if we were >>>> a primary process sending messages to secondary processes. >>> >>> Yes, I also think it is good to return number of sends. >>> Then caller can compare number of sended requests with number of >>> received replies and decide should it be considered a failure or no. >>> >> >> Well, OK, that might make sense. However, i think it would've be of more >> value to make the API consistent (0/-1 on success/failure) and put >> number of sent messages into the reply, like number of received. I.e. >> something like >> >> struct reply { >> int nb_sent; >> int nb_received; >> }; >> >> We do it for the latter already, so why not the former? > > The question is what treat as success/failure? > Let say we sent 2 requests (of 3 possible), got back 1 response... > Should we consider it as success or failure? > I think "failure" is "something went wrong", not "secondary processes didn't respond". For example, invalid parameters, or our socket suddenly being closed, or some other error that prevents us from sending requests to secondaries. As far as i can tell from the code, there's no way to know if the secondary process is running other than by attempting to connect to it, and get a response. So, failed connection should not be a failure condition, because we can't know if we *can* connect to the process until we do. Process may have ended, but socket files will still be around, and there's nothing we can do about that. So i wouldn't consider inability to send a message a failure condition. -- Thanks, Anatoly