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

From: Thomas Monjalon <thomas@monjalon.net>
To: Ferruh Yigit <ferruh.yigit@intel.com>
Cc: "Yang, Zhiyong" <zhiyong.yang@intel.com>,
	dev@dpdk.org, Matan Azrad <matan@mellanox.com>,
	"Iremonger, Bernard" <bernard.iremonger@intel.com>,
	"Yao, Lei A" <lei.a.yao@intel.com>,
	"maxime.coquelin@redhat.com" <maxime.coquelin@redhat.com>,
	"Bie, Tiwei" <tiwei.bie@intel.com>,
	"stable@dpdk.org" <stable@dpdk.org>,
	Harry Van Haaren <harry.van.haaren@intel.com>
Subject: Re: [PATCH v2] app/testpmd: fix pmd_test_exit function for vdevs
Date: Tue, 22 May 2018 21:48:37 +0200	[thread overview]
Message-ID: <3059388.qb94XYSleL@xps> (raw)
In-Reply-To: <45bf17fa-fb43-7917-8cf6-63864f9d2c4c@intel.com>

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
> >> 	2/ add a FIXME comment in testpmd code explaining the workaround
> >> 	3/ commit to work on rte_eal_cleanup() in 18.08
> 
> 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