From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from out3-smtp.messagingengine.com (out3-smtp.messagingengine.com [66.111.4.27]) by dpdk.org (Postfix) with ESMTP id B258F4CA5 for ; Mon, 22 Oct 2018 08:55:36 +0200 (CEST) Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailout.nyi.internal (Postfix) with ESMTP id 3386422E1C; Mon, 22 Oct 2018 02:55:36 -0400 (EDT) Received: from mailfrontend2 ([10.202.2.163]) by compute1.internal (MEProxy); Mon, 22 Oct 2018 02:55:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=monjalon.net; h= from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding:content-type; s=mesmtp; bh=4O+7UZfxZq1UCOIY4X/HKjFmTBa9vRAGhoD5gKed7mk=; b=MpGDepUalUj0 pENhhg5n8FLwWXVa8cqbvCrY8qXC28DS26+ivKa14O6ulJdZX5NXSZ2a4/0puRzQ 3LpYOnZ/m1fNvkXugaGOpfE0+kjUWNWAq7eSxYsvlJ/jxm9FLeUZ75IRUgbK639c TDL6sXm6Oef1QbEAsksEfNypLq0Mm18= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender :x-sasl-enc; s=fm1; bh=4O+7UZfxZq1UCOIY4X/HKjFmTBa9vRAGhoD5gKed7 mk=; b=Zb25M3GfSMDZkbzXJpYKma4A50So4bdPj5kqIMHgEdf7CdnFA0/fw+8v3 lvGCJvfrHl5JR2sUrTFgXzWCTaWAcKWjPu0Ly/8EIOwqR00APxtImNzFVAbaciu4 yykgFaDI5T/g9xzuweu8qO9uuTsWV6WR/0qu7jMFgeNV8c9KO/i+H9shpNOqEYTU dQZsF9eYOveTb65H4CW/8h/24YcqcOiuHqdK2ag3jEsX1YDzJunNyaA564aIiG7J VkpTl1WarG/sh5RHJvm0iDWOC6KgjDBvEGrzyARtxUhvkgZup0HWtdVgLIrrNvp2 d7AsigRlSEXAH6LCNPaDelin+YQPA== X-ME-Sender: X-ME-Proxy: Received: from xps.localnet (184.203.134.77.rev.sfr.net [77.134.203.184]) by mail.messagingengine.com (Postfix) with ESMTPA id 8C710102EA; Mon, 22 Oct 2018 02:55:34 -0400 (EDT) From: Thomas Monjalon To: Hideyuki Yamashita Cc: dev@dpdk.org, Gaetan Rivet Date: Mon, 22 Oct 2018 08:55:35 +0200 Message-ID: <8808967.KerV1MckpC@xps> In-Reply-To: <201810220434.w9M4YmRb005231@ccmail04.silk.ntt-tx.co.jp> References: <201809271040.w8RAegUP030722@ccmail04.silk.ntt-tx.co.jp> <3832325.ptN2KYLa6n@xps> <201810220434.w9M4YmRb005231@ccmail04.silk.ntt-tx.co.jp> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Subject: Re: [dpdk-dev] How to replace rte_eth_dev_attach with rte_eal_hotplug_add 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, 22 Oct 2018 06:55:37 -0000 Hi, I am actively working on it. Look how rte_eth_dev_attach is replaced in testpmd: https://patches.dpdk.org/patch/47019/ It is using a new ethdev iterator RTE_ETH_FOREACH_MATCHING_DEV. 22/10/2018 06:34, Hideyuki Yamashita: > Dear Thomas and all, > > About a month ago, I posted the topic related with > how to replace rte_eth_dev_attach. > > Following your advice, > my code would be as below: > (Old code using deprecated API is commented out) > > rte_eth_dev_get_port_by_name is used to retrieve dpdk port > after rte_eal_hotplug_add. > Note that my application is just one of the dpdk applications(in the host) > and within the process, only one thread handles device attatch/detach. > (No race condition with regard to device hot_plug will > not take place) > ------------------------------------------------------------------- > //ret = rte_eth_dev_attach(devargs, &vhost_port_id); > //if (ret < 0) > // return ret; > > struct rte_devargs da; > > memset(&da, 0, sizeof(da)); > > /* parse devargs */ > if (rte_devargs_parse(&da, devargs)) > return -1; > ret = rte_eal_hotplug_add(da.bus->name, da.name, da.args); > if (ret < 0) { > free(da.args); > return ret; > } > free(da.args); > ret = rte_eth_dev_get_port_by_name(da.name, &vhost_port_id); > if (ret < 0) > return ret; > ----------------------------------------------------------------------------- > > If you have any concerns/additional advices, please let me know. > > BR, > Hideyuki Yamashita > NTT TechnoCross > > > > 27/09/2018 12:40, Hideyuki Yamashita: > > > Dear Thomas, > > > > > > Thansk for your answer. > > > Please see inline. > > > > > > > 27/09/2018 03:38, Hideyuki Yamashita: > > > > > Dear Thomas, > > > > > > > > > > Thanks for your answer. > > > > > It took me a little time to digest answer. > > > > > Please see inline. > > > > > > > > > > > > > > > > 21/09/2018 09:19, Hideyuki Yamashita: > > > > > > > Dear Gaetan and Thomas, > > > > > > > > > > > > > > Thanks for your answer. > > > > > > > Please see inline. > > > > > > > > > > > > > > > 20/09/2018 11:09, Ga?an Rivet: > > > > > > > > > On Thu, Sep 20, 2018 at 05:46:37PM +0900, Hideyuki Yamashita wrote: > > > > > > > > > > Hello, > > > > > > > > > > > > > > > > > > > > From dpdk 18.08 release rte_eth_dev_attach and > > > > > > > > > > rte_eth_dev_detach becom deprecated API and > > > > > > > > > > it is recommended to replace with rte_eal_hotplug_add > > > > > > > > > > and rte_eal_hotplug_remove. > > > > > > > > > > > > > > > > > > > > My program uses above mentioned deprecated APIs > > > > > > > > > > and have to replace those. > > > > > > > > > > Note that my program uses attach to attach vhost, pcap pmd. > > > > > > > > > > > > > > > > > > > > My question is whether it is correct to replace those as following: > > > > > > > > > > find rte_eth_dev_attach function in rte_ethdev.c and > > > > > > > > > > migrate those content into my program. > > > > > > > > > > > > > > > > > > > > e.g. > > > > > > > > > > lib/librte_ethdev/rte_ethdev.c line 643-686 for attach > > > > > > > > > > lib/librte_ethdev/rte_ethdev.c line 690-720 for detach > > > > > > > > > > > > > > > > > > > > Your advice/guidance are much appreciated. > > > > > > > > > > Thanks! > > > > > > > > > > > > > > > > > > Hello Hideyuki, > > > > > > > > > > > > > > > > > > You could use this code for guidance, while leaving the ethdev > > > > > > > > > specificities such as verifying the eth_dev_count_total(). The hotplug > > > > > > > > > function would already return an error if the PMD was not able to create > > > > > > > > > the necessary devices. > > > > > > > > > > > > > > > > > > The main issue might be to find the port_id of your new port. > > > > > > > > > You won't be able to use eth_dev_last_created_port, so you would have to > > > > > > > > > iterate over the ethdev using RTE_ETH_FOREACH_DEV and find the one > > > > > > > > > matching your parameters (you might for example match the rte_device > > > > > > > > > name with the name you used in hotplug_add, as there is no standard > > > > > > > > > naming scheme at the ethdev level). > > > > > > > First of all, thank for your answering to my question. > > > > > > > But I have questions. > > > > > > > (Sorry, I have poor knowledge about dpdk and have many basic questions) > > > > > > > > > > > > > > Q1. > > > > > > > Why eth_dev_last_created_port can not be used? > > > > > > > When I look into rte_eth_dev_atthach in 18.08, it calls > > > > > > > > > > > > > > *port_id = eth_dev_last_created_port; > > > > > > > > > > > > > > at the end of the function. > > > > > > > > > > > > You can have a race condition. > > > > > Please elaborate me a bit more. > > > > > > > > > > Is it correct understanding that race condition > > > > > includes > > > > > - read information before port is available > > > > > - other device may be plugged (or unplugged) > > > > > and so using "eth_dev_last_created_port" is > > > > > NOT reliable? > > > > > > > > I am thinking about the second one only. > > > > > > If we assume there is only one DPDK application > > > inside the host and within the application, only one thread > > > handles attach/detach of devices, then is it ok to use > > > > > > > *port_id = eth_dev_last_created_port; > > > because there seems no possiblity race condition > > > takes place? > > > > If you are never probing a new port outside of this thread, > > I guess it's OK. > > Take care of not attaching from the interrupt thread too! > > > > > > > >