From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ferruh Yigit Subject: Re: [RFC] ethdev: complete closing to free all resources Date: Fri, 28 Sep 2018 13:46:09 +0100 Message-ID: References: <20180907233929.21950-1-thomas@monjalon.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: dev@dpdk.org To: Thomas Monjalon , arybchenko@solarflare.com Return-path: Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by dpdk.org (Postfix) with ESMTP id 86B251B429 for ; Fri, 28 Sep 2018 14:47:02 +0200 (CEST) In-Reply-To: <20180907233929.21950-1-thomas@monjalon.net> Content-Language: en-US List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 9/8/2018 12:39 AM, Thomas Monjalon wrote: > After closing a port, it cannot be restarted. > So there is no reason to not free all associated resources. > > The last step was done with rte_eth_dev_detach() which is deprecated. > Instead of removing the associated rte_device, the driver should check > if no more port (ethdev, cryptodev, etc) is still open for the device. > Then the device resources can be freed by the driver inside the > dev_close() driver callback operation. > > The last ethdev freeing (dev_private and final release), which were done > by rte_eth_dev_detach(), are now done at the end of rte_eth_dev_close(). > > Signed-off-by: Thomas Monjalon > --- > This patch contains only the change in the close function as RFC. > > This idea was presented at Dublin during the "hotplug talk". > --- > lib/librte_ethdev/rte_ethdev.c | 5 +++++ > lib/librte_ethdev/rte_ethdev.h | 5 +++-- > 2 files changed, 8 insertions(+), 2 deletions(-) > > diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c > index 4c3202505..071fcbd23 100644 > --- a/lib/librte_ethdev/rte_ethdev.c > +++ b/lib/librte_ethdev/rte_ethdev.c > @@ -1358,6 +1358,7 @@ void > rte_eth_dev_close(uint16_t port_id) > { > struct rte_eth_dev *dev; > + struct rte_bus *bus; > > RTE_ETH_VALID_PORTID_OR_RET(port_id); > dev = &rte_eth_devices[port_id]; > @@ -1372,6 +1373,10 @@ rte_eth_dev_close(uint16_t port_id) > dev->data->nb_tx_queues = 0; > rte_free(dev->data->tx_queues); > dev->data->tx_queues = NULL; > + > + rte_free(dev->data->dev_private); > + > + rte_eth_dev_release_port(dev); These already done in: rte_eth_dev_pci_generic_remove() rte_eth_dev_pci_release() Perhaps all content of rte_eth_dev_pci_release(), including above updates, should move to rte_eth_dev_close() and rte_eth_dev_pci_generic_remove() call rte_eth_dev_close() directly. Just thinking aloud, driver->probe() called when a new device added. Application startup can be thought as all devices added one by one. [Perhaps this can be change in the future to add devices only when explicitly stated] driver->remove() called when device removed. When application terminated this path not called at all, perhaps we need a way to remove all devices one by one on exit. eth_dev_close(), when eth_dev removed in ethdev layer but device is not removed in eal level, I think it make sense for eth_dev_close(): - It does more cleanup, free resources and port_id - but it may need to do more clean up, like call uninit() and do more driver internal clean up too, and clean up the hw. - so call stack can be: driver->remove() rte_eth_dev_pci_generic_remove() eth_dev_close() dev_uninit() [driver unint function ] Another question, after eth_dev_close() ethdev is not usable and not able to restart it back. So why we need eth_dev_close() in addition to dev remove, why not directly call rte_eth_dev_detach()? > } > > int > diff --git a/lib/librte_ethdev/rte_ethdev.h b/lib/librte_ethdev/rte_ethdev.h > index 7070e9ab4..37a757a7a 100644 > --- a/lib/librte_ethdev/rte_ethdev.h > +++ b/lib/librte_ethdev/rte_ethdev.h > @@ -1797,8 +1797,9 @@ int rte_eth_dev_set_link_down(uint16_t port_id); > > /** > * Close a stopped Ethernet device. The device cannot be restarted! > - * The function frees all resources except for needed by the > - * closed state. To free these resources, call rte_eth_dev_detach(). > + * The function frees all port resources. > + * If there is no more port associated with the underlying device, > + * the driver should free the device resources. > * > * @param port_id > * The port identifier of the Ethernet device. >