From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail04.ics.ntt-tx.co.jp (mail05.ics.ntt-tx.co.jp [210.232.35.69]) by dpdk.org (Postfix) with ESMTP id 9D3711B600 for ; Mon, 17 Dec 2018 13:12:00 +0100 (CET) Received: from gwchk03.silk.ntt-tx.co.jp (gwchk03.silk.ntt-tx.co.jp [10.107.0.111]) by mail04.ics.ntt-tx.co.jp (unknown) with ESMTP id wBHCBwTJ012950; Mon, 17 Dec 2018 21:11:58 +0900 Received: (from root@localhost) by gwchk03.silk.ntt-tx.co.jp (unknown) id wBHCBwUx003758; Mon, 17 Dec 2018 21:11:58 +0900 Received: from gwchk.silk.ntt-tx.co.jp [10.107.0.110] by gwchk03.silk.ntt-tx.co.jp with ESMTP id XAA03757; Mon, 17 Dec 2018 21:11:58 +0900 Received: from imss06.silk.ntt-tx.co.jp (localhost [127.0.0.1]) by ccmail04.silk.ntt-tx.co.jp (unknown) with ESMTP id wBHCBw51001755; Mon, 17 Dec 2018 21:11:58 +0900 Received: from imss06.silk.ntt-tx.co.jp (localhost [127.0.0.1]) by imss06.silk.ntt-tx.co.jp (unknown) with ESMTP id wBHCBwnF013466; Mon, 17 Dec 2018 21:11:58 +0900 Received: from ccmail04 (smtp03.silk.ntt-tx.co.jp [10.107.0.135]) by imss06.silk.ntt-tx.co.jp (unknown) with SMTP id wBHCBwe2013463; Mon, 17 Dec 2018 21:11:58 +0900 Date: Mon, 17 Dec 2018 21:10:27 +0900 From: Hideyuki Yamashita In-Reply-To: <272166ee-d05f-528a-06c9-962e3237674e@intel.com> References: <201812171046.wBHAkViW032759@ccmail04.silk.ntt-tx.co.jp> <272166ee-d05f-528a-06c9-962e3237674e@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="ISO-2022-JP" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.74 [ja] X-CCMail7: CC-Mail-V7.0.2-Client-Relayed Message-Id: <201812171211.wBHCBgf1001687@ccmail04.silk.ntt-tx.co.jp> X-TM-AS-MML: No X-CC-Mail-RelayStamp: CC-Mail-V5.14-Server To: "Burakov, Anatoly" Cc: dev@dpdk.org, Yasufumi Ogawa , Nakamura Hioryuki Subject: Re: [dpdk-dev] rte_eal_hotplug_remove() generates error message 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, 17 Dec 2018 12:12:01 -0000 > On 17-Dec-18 10:45 AM, Hideyuki Yamashita wrote: > >> On 17-Dec-18 10:02 AM, Hideyuki Yamashita wrote: > >>> Dear Thomas and all, > >>> > >>> I took a look on dpdk code. > >>> I firstly write qustions and my analisys > >>> on the current dpdk code follows after that. > >>> > >>> [1.Questions] > >>> I have several questions to ask again. > >>> Is my understanding correct about followings > >>> > >>> Q1: "EAL:ERROR, Invalid memory" is ignorable > >>> > >>> Q2: there is no big difference between calling > >>> rte_eal_hotplug_remove(bus->name, dev->name) > >>> and > >>> rte_dev_remove(dev) because anyway it > >>> reaches to rte_pmd_vhost_remove and encounter > >>> the same error. > >>> > >>> [2.snip from my code] > >>> ..... > >>> rte_eth_dev_close(port_id); > >>> ret = rte_dev_remove(dev); > >>> if (ret < 0) > >>> return ret; > >>> rte_eth_dev_release_port(&rte_eth_devices[port_id]); > >>> > >>> [3. My analysis on dpdk code] > >>> static int > >>> rte_pmd_vhost_remove(struct rte_vdev_device *dev) > >>> { > >>> ........... > >>> 　eth_dev_close(eth_dev); > >>> > >>> rte_free(vring_states[eth_dev->data->port_id]); > >>> vring_states[eth_dev->data->port_id] = NULL; > >>> > >>> rte_eth_dev_release_port(eth_dev); > >>> > >>> As you can see in rte_eth_vhost.c > >>> It calls both eth_dev_close and rte_eth_dev_release_port. > >>> And inside both functions, it tries to free mac_addrs. > >>> rte_free(dev->data->mac_addrs); //in rth_dev_close > >>> rte_free(eth_dev->data->mac_addrs); //in rte_eth_dev_release_port > >>> > >>> I understand that is the reason why > >>> /* Free the memory space back to heap */ > >>> void rte_free(void *addr) > >>> { > >>> if (addr == NULL) return; > >>> if (malloc_heap_free(malloc_elem_from_data(addr)) < 0) > >>> RTE_LOG(ERR, EAL, "Error: Invalid memory\n"); > >>> } > >>> encounter the error. > >>> As an experiment, I commented out one of them, "ERR, Invalid memory" > >>> disappered. > >>> > >>> Thanks and BR, > >>> Hideyuki Yamashita > >>> NTT TechnoCross > >>> > >>>> Adding my colleague Yasufumi and Hiroyuki as CC. > >>>> > >>>> We are waiting valuable advice from you. > >>>> > >>>> Thanks in advance, > >>>> Hideyuki Yamashita > >>>> NTT TechnoCross > >>>> > >>>>> > >>>>> Dear Thomas and all, > >>>>> > >>>>> I hope you all get safely back home after DPDK summit. > >>>>> (When I get back Japan, it is chilling. (start of winter)) > >>>>> > >>>>> On DPDK 18.11.0, we tried to remove vhost device by using rte_eal_hotplug_remove(). > >>>>> However, following syslog message is printed. > >>>>> “EAL: Error: Invalid memory” > >>>>> > >>>>> At DPDK summit San Jose, we had chance to ask Thomas how to handle the error message, and he gave us following advice: > >>>>> Replace “rte_eal_hotplug_add()” to “rte_dev_probe(devargs)” and > >>>>> “rte_eal_hotplug_remove()” to “rte_eth_dev_close() and rte_dev_remove(rte_dev)” > >>>>> > >>>>> We tested above changes, but the result is the same (i.e., same error message is printed). > >>>>> The debug log message says: > >>>>> --- > >>>>> [primary] > >>>>> VHOST_CONFIG: vhost-user server: socket created, fd: 17 > >>>>> VHOST_CONFIG: bind to /tmp/sock0 > >>>>> EAL: Error: Invalid memory > >>>>> VHOST_CONFIG: vhost-user server: socket created, fd: 17 > >>>>> VHOST_CONFIG: bind to /tmp/sock0 > >>>>> > >>>>> [secondary] > >>>>> APP: devargs=eth_vhost0,iface=/tmp/sock0,queues=1 > >>>>> EAL: request: eal_dev_mp_request > >>>>> EAL: msg: eal_dev_mp_request > >>>>> EAL: request: bus_vdev_mp > >>>>> EAL: msg: bus_vdev_mp > >>>>> EAL: msg: bus_vdev_mp > >>>>> EAL: reply: eal_dev_mp_request > >>>>> EAL: msg: eal_dev_mp_request > >>>>> rte_eth_promiscuous_disable: Function not supported > >>>>> rte_eth_allmulticast_disable: Function not supported > >>>>> APP: To Server: add > >>>>> EAL: request: eal_dev_mp_request > >>>>> EAL: msg: eal_dev_mp_request > >>>>> EAL: reply: eal_dev_mp_request > >>>>> EAL: msg: eal_dev_mp_request > >>>>> APP: To Server: del > >>>>> APP: devargs=eth_vhost0,iface=/tmp/sock0,queues=1 > >>>>> EAL: request: eal_dev_mp_request > >>>>> EAL: msg: eal_dev_mp_request > >>>>> EAL: request: bus_vdev_mp > >>>>> EAL: msg: bus_vdev_mp > >>>>> EAL: msg: bus_vdev_mp > >>>>> EAL: reply: eal_dev_mp_request > >>>>> EAL: msg: eal_dev_mp_request > >>>>> rte_eth_promiscuous_disable: Function not supported > >>>>> rte_eth_allmulticast_disable: Function not supported > >>>>> APP: To Server: add > >>>>> --- > >>>>> > >>>>> We would like to ask: > >>>>> 1) Is the message “EAL: Error: Invalid memory” ignorable or not? There is no obstacle except this message to re-add the vhost device. > >>>>> 2) Which is the better(best?) way to add/del vhost device “rte_eal_hotplug_add/remove()” or the way Thomas suggested? > >>>>> > >>>>> Thanks in advance and have a nice day. > >>>>> > >>>>> BR, > >>>>> Hideyuki Yamashita > >>>>> NTT TechnoCross > >>>> > >>> > >>> > >>> > >> Hi Hideyuki, > >> > >> The error you're referring to (about invalid memory) means that you're trying to free a pointer that points to invalid memory. Meaning, either the pointer itself is not pointing to an allocated area, or it points to memory that has already been freed. > >> > >> If dev->data->mac_addrs and eth_dev->data->mac_addrs point to the same area, this is a bug, because this would lead to double free, and rte_malloc will rightly complain about invalid memory. Now, malloc won't try to do anything with the invalid memory, so the error itself is harmless *as far as malloc is concerned*, but these attempts to free the memory twice should be fixed whereever they happen. > >> > >> I'm not well-versed in dev infrastructure, so i wouldn't be able to say which one of the rte_free calls is an extra, unneeded one. This is something e.g. Thomas could help with, or the driver maintainer. > >> > >> --Thanks, > >> Anatoly > > Hello Anatoly, > > > > Thanks for your reply for my newbie question. > > Now I understand that this error is harmless from DPDK application(SPP) > > point of view in practice. Thanks. > > But anyway if there is a double free logic, it is a bug and should be > > fixed. > > The remaining issues are > > 1. If it is really a bug (or my mis-understanding) > > 2. If is is a bug which function should remove rte_free(mac_addrs) > > From description, it looks like a bug. Correct usage of API (rte_dev_close() followed by rte_dev_remove()) should not trigger any errors. You might want to create a BugZilla entry describing the issue. > > > > > Thanks, > > Hideyuki Yamashita > > NTT TechnoCross > > > > > > --Thanks, > Anatoly Hello Thanks for your reply again. I would like to wait for a while(at least a day) to hear opnion from other people including Thomas or maintainer. In addition I have to learn how to file bug in Bugzzilla for DPDK. Thanks, Hideyuki Yamashita NTT TechnoCross