Re: [dpdk-dev] CALL to eth PMD maintainers: complete closing of port

[Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>]

On Monday, September 09/14/20, 2020 at 00:16:17 +0200, Thomas Monjalon wrote:
> The patches for removing RTE_ETH_DEV_CLOSE_REMOVE are sent:
> 	https://patches.dpdk.org/project/dpdk/list/?series=12173
> 
> 11 drivers are not supporting the new behaviour correctly:
> 	bnx2x, cxgbe, dpaa, dpaa2, enetc, ionic,
> 	ipn3ke, liquidio, nfp, pfe, qede
> 
> If you are the maintainer of one of these drivers,
> you can still consider fixing it in the next days.
> 

The RTE_ETH_DEV_CLOSE_REMOVE migration for CXGBE PMD has already been
submitted two weeks ago [1].

[1] https://patches.dpdk.org/patch/76271/

Thanks,
Rahul

> 
> 12/09/2020 13:25, Thomas Monjalon:
> > 03/08/2020 20:50, Thomas Monjalon:
> > > 18/04/2019 12:59, Thomas Monjalon:
> > > > Hi all,
> > > > 
> > > > Since DPDK 18.11, the behaviour of the close operation is changed
> > > > if RTE_ETH_DEV_CLOSE_REMOVE is enabled in the driver:
> > > > port is released (i.e. totally freed and data erased) on close.
> > > > This new behaviour is enabled per driver for a migration period.
> > > > 
> > > > Looking at the code, you can see these comments:
> > > > /* old behaviour: only free queue arrays */
> > > > RTE_ETHDEV_LOG(DEBUG, "Port closing is using an old behaviour.\n"
> > > > 	"The driver %s should migrate to the new behaviour.\n",
> > > > /* new behaviour: send event + reset state + free all data */
> > > > 
> > > > You can find an advice in the commit:
> > > > 	http://git.dpdk.org/dpdk/commit/?id=23ea57a2a
> > > > "
> > > > When enabling RTE_ETH_DEV_CLOSE_REMOVE,
> > > > the PMD must free all its private resources for the port,
> > > > in its dev_close function.
> > > > It is advised to call the dev_close function in the remove function
> > > > in order to support removing a device without closing its ports.
> > > > "
> > > > 
> > > > It would be great to complete this migration for the next LTS
> > > > version, which will be 19.11.
> > > 
> > > For the record, it did not happen in 19.11.
> > > 
> > > > Following drivers should be migrated:
> > > > ( find drivers/net -mindepth 1 -maxdepth 1 -type d | cut -d/ -f3 ; git grep -l RTE_ETH_DEV_CLOSE_REMOVE drivers | cut -d/ -f3 ) | sort | uniq -u
> > > [...]
> > > 
> > > The progress in April 2019 was 4 of 46 (9%).
> > > 
> > > > Please let's progress smoothly on this topic, thanks.
> > > 
> > > More than one year later, the progress is 26 of 53 (49%).
> > > 
> > > > The concerned maintainers (Cc) can be found with the following command:
> > > > devtools/get-maintainer.sh $(( find drivers/net -mindepth 1 -maxdepth 1 -type d | cut -d/ -f-3 ; git grep -l RTE_ETH_DEV_CLOSE_REMOVE drivers ) | sort | uniq -u)
> > > 
> > > We cannot wait forever. Temporary cannot be longer than 2 years.
> > > I am going to send a deprecation notice to remove the "temporary"
> > > flag RTE_ETH_DEV_CLOSE_REMOVE.
> > 
> > The deprecation notice was merged in 20.08:
> > 	http://mails.dpdk.org/archives/dev/2020-August/177314.html
> > 
> > > It will break drivers which are not migrated.
> > > It will probably help to find motivation in new priorities.
> > > 
> > > More details on what to do can be found in this mail thread:
> > > 	http://inbox.dpdk.org/dev/1748144.UFpUr2FPnr@xps/
> > 
> > Summary:
> > 
> > * The freeing of private port resources must be moved in the PMD
> > from the ".remove(device)" function to the ".dev_close(port)" function.
> > 
> > * If a generic resource (.mac_addrs or .hash_mac_addrs) cannot be freed,
> > it must be set to NULL in ".dev_close" PMD function to protect from
> > subsequent rte_eth_dev_release_port() freeing.
> > 
> > * Note 1:
> > The generic resources are freed in rte_eth_dev_release_port(),
> > after ".dev_close" is called in rte_eth_dev_close(), but not when
> > calling ".dev_close" directly from the ".remove" PMD function.
> > That's why rte_eth_dev_release_port() must still be called explicitly
> > from ".remove(device)" after calling the ".dev_close" PMD function.
> > 
> > * Note 2:
> > If a device can have multiple ports, the common resources must be freed
> > only in the ".remove(device)" function.
> > 
> > * Note 3:
> > The port is supposed to be in a stopped state when it is closed.
> > If it is not the case, it is free to the PMD implementation
> > how to react when trying to close a non-stopped port:
> > either try to stop it automatically or just return an error.
> 
> 
>