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 201A81B893 for ; Mon, 17 Dec 2018 11:46:48 +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 wBHAkltD005166; Mon, 17 Dec 2018 19:46:47 +0900 Received: (from root@localhost) by gwchk03.silk.ntt-tx.co.jp (unknown) id wBHAkloc021874; Mon, 17 Dec 2018 19:46:47 +0900 Received: from gwchk.silk.ntt-tx.co.jp [10.107.0.110] by gwchk03.silk.ntt-tx.co.jp with ESMTP id VAA21873; Mon, 17 Dec 2018 19:46:47 +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 wBHAklnT000353; Mon, 17 Dec 2018 19:46:47 +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 wBHAkk6b003746; Mon, 17 Dec 2018 19:46:46 +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 wBHAkkYN003743; Mon, 17 Dec 2018 19:46:46 +0900 Date: Mon, 17 Dec 2018 19:45:15 +0900 From: Hideyuki Yamashita In-Reply-To: <0eb59f12-0192-a234-a773-7f3061abea3a@intel.com> References: <201812171004.wBHA432F013027@ccmail04.silk.ntt-tx.co.jp> <0eb59f12-0192-a234-a773-7f3061abea3a@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: <201812171046.wBHAkViW032759@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 10:46:49 -0000 > 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) Thanks, Hideyuki Yamashita NTT TechnoCross