Re: [dpdk-dev] [PATCH v2] app/testpmd: fix pmd_test_exit function for vdevs

[Thomas Monjalon <thomas@monjalon.net>]

23/05/2018 13:37, Yang, Zhiyong:
> From: Yang, Zhiyong
> > 
> > Hi Thomas,
> > 
> > From: Thomas Monjalon [mailto:thomas@monjalon.net]
> > > 22/05/2018 20:38, Ferruh Yigit:
> > > > On 5/22/2018 2:12 PM, Thomas Monjalon wrote:
> > > > > Any update to improve this workaround?
> > > > >
> > > > > 21/05/2018 18:38, Thomas Monjalon:
> > > > >> 21/05/2018 18:32, Ferruh Yigit:
> > > > >>> On 5/21/2018 11:54 AM, Thomas Monjalon wrote:
> > > > >>>> 19/05/2018 16:19, Thomas Monjalon:
> > > > >>>>> 18/05/2018 18:29, Ferruh Yigit:
> > > > >>>>>> On 5/18/2018 4:55 PM, Matan Azrad wrote:
> > > > >>>>>>> Hi all
> > > > >>>>>>>
> > > > >>>>>>> While this patch also applied I don't understand it.
> > > > >>>>>>> Is it mandatory for each PMD to free all its resources in
> > dev_close()?
> > > > >>>>>>> Or it should be done by the rte_device remove function?
> > > > >>>>>>>
> > > > >>>>>>> If the resource cleanup should be done by the remove
> > > > >>>>>>> function I think it should be called for all the devices (pci, vdev,
> > etc).
> > > > >>>>>>>
> > > > >>>>>>> Is there an exit function for EAL to clean rte_eal_init()?
> > > > >>>>>>> If no, looks
> > > like we need it...
> > > > >>>>>>
> > > > >>>>>> Hi Matan,
> > > > >>>>>>
> > > > >>>>>> I believe there is a gap in resource cleanup.
> > > > >>>>>> dev_close() it not for resource cleanup, it should be in PMD
> > > > >>>>>> remove() functions, and PMDs have it. The problem is remove
> > > > >>>>>> path is
> > > not called in application exit.
> > > > >>>>>>
> > > > >>>>>> As far as I know there is no simple API to clean the
> > > > >>>>>> resources, having it may help application to do the cleanup.
> > > > >>>>>>
> > > > >>>>>> I have seen the rte_eal_cleanup() API by Harry, that can be
> > > > >>>>>> extended to cover PMD resource cleanup if there is enough
> > > motivation for it.
> > > > >>>>>
> > > > >>>>> Yes, EAL resources should be removed by the function
> > > rte_eal_cleanup().
> > > > >>>>> And ethdev ports must be removed by rte_eth_dev_close().
> > > > >>>>
> > > > >>>> This patch is relying on rte_eth_dev_detach() to remove the EAL
> > device.
> > > > >>>> It should be done in rte_eal_cleanup().
> > > > >>>>
> > > > >>>> I am concerned that this patch is workarounding a miss in
> > > > >>>> rte_eal_cleanup, and takes a different action only for vdev. It
> > > > >>>> is a bad
> > > example.
> > > > >>>
> > > > >>> Indeed it does workaround, but it is needed to fix a defect in virtio-user.
> > > > >>
> > > > >> The defect is still in virtio-user after this patch.
> > > > >> To make this workaround acceptable, you need:
> > > > >> 	1/ add the virtio-user known issue in release notes
> > 
> > I don't think it is a bug for virtio-user. Just no proper implemented API can free
> > the virtio-user resources  allocated by probe method.
> > Socket file is just one example,  other resources are freed in the remove
> > method.  Testpmd was always missing the functionality.
> > 
> > > > >> 	2/ add a FIXME comment in testpmd code explaining the workaround
> > > > >> 	3/ commit to work on rte_eal_cleanup() in 18.08
> 
> Do you mean to work on rte_eal_cleanup() for all drivers or for virtio user only?

Yes, we need to call the remove() functions of all drivers from rte_eal_cleanup().


> > > > I have submitted following patch [1], can it cover 2/ for the v18.05-rc5?
> > > >
> > > > [1]
> > > > https://dpdk.org/dev/patchwork/patch/40350/
> > >
> > > Yes, it covers item 2/. Thanks
> > >
> > >
> > 
> > rte_eal_cleanup() is a proper API,  which is needed to clean up resources.
> > 
> > Thanks
> > Zhiyong