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

[Rasesh Mody]

Hi Thomas,

>From: dev <dev-bounces at dpdk.org> On Behalf Of Thomas Monjalon
>Sent: Sunday, September 13, 2020 3:16 PM
>
>The patches for removing RTE_ETH_DEV_CLOSE_REMOVE are sent:
>	https://urldefense.proofpoint.com/v2/url?u=https-
>3A__patches.dpdk.org_project_dpdk_list_-3Fseries-
>3D12173&d=DwICAg&c=nKjWec2b6R0mOyPaz7xtfQ&r=Vhi2FR3R84xPMUtUhj
>NPxoiMSxcj1IW0xDKEoZ0F00o&m=9C_CX6dJtCkd6pU6mUDB8eV-
>EorzP6ErRLFuCc-dtTg&s=8L7RxyHhOuIXf3MBurNOeqvGa-gGhH1NY9vnoj-
>fXM4&e=
>
>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 fixes for bnx2x and qede PMDs are posted.
https://patches.dpdk.org/patch/78779/
https://patches.dpdk.org/patch/78780/

Thanks!
-Rasesh
>
>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:
>> > >
>> > > https://urldefense.proofpoint.com/v2/url?u=http-3A__git.dpdk.org_d
>> > > pdk_commit_-3Fid-
>3D23ea57a2a&d=DwICAg&c=nKjWec2b6R0mOyPaz7xtfQ&r=V
>> > >
>hi2FR3R84xPMUtUhjNPxoiMSxcj1IW0xDKEoZ0F00o&m=9C_CX6dJtCkd6pU6m
>UDB8
>> > > eV-EorzP6ErRLFuCc-
>dtTg&s=23dp27AoThshb5NflUTFh3HH3M_KPwa8Svd2TOeN9
>> > > gs&e=
>> > > "
>> > > 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:
>>
>> https://urldefense.proofpoint.com/v2/url?u=http-3A__mails.dpdk.org_arc
>> hives_dev_2020-
>2DAugust_177314.html&d=DwICAg&c=nKjWec2b6R0mOyPaz7xtfQ&
>>
>r=Vhi2FR3R84xPMUtUhjNPxoiMSxcj1IW0xDKEoZ0F00o&m=9C_CX6dJtCkd6p
>U6mUDB8e
>> V-EorzP6ErRLFuCc-dtTg&s=PRJ-
>nWVm0NO6WrpQDWaI0ocSwaIDowsMQNWrif0FDgg&e=
>>
>> > 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:
>> >
>> > https://urldefense.proofpoint.com/v2/url?u=http-3A__inbox.dpdk.org_d
>> > ev_1748144.UFpUr2FPnr-
>40xps_&d=DwICAg&c=nKjWec2b6R0mOyPaz7xtfQ&r=Vhi
>> >
>2FR3R84xPMUtUhjNPxoiMSxcj1IW0xDKEoZ0F00o&m=9C_CX6dJtCkd6pU6mU
>DB8eV-E
>> > orzP6ErRLFuCc-
>dtTg&s=00JuVYCjq_EZW27VmszpI4E8Yq_dN9oGjewjBTaCZ9s&e=
>>
>> 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.
>
>