Re: [dpdk-dev] [RFC V1] examples/l3fwd-power: fix memory leak for rte_pci_device

[Thomas Monjalon <thomas@monjalon.net>]

26/09/2021 14:20, Huisong Li:
> 在 2021/9/18 16:46, Thomas Monjalon 写道:
> > 18/09/2021 05:24, Huisong Li:
> >> 在 2021/9/17 20:50, Thomas Monjalon 写道:
> >>> 17/09/2021 04:13, Huisong Li:
> >>>> How should PMD free it? What should we do? Any good suggestions?
> >>> Check that there is no other port sharing the same PCI device,
> >>> then call the PMD callback for rte_pci_remove_t.
> >> For primary and secondary processes, their rte_pci_device is independent.
> > Yes it requires to free on both primary and secondary.
> >
> >> Is this for a scenario where there are multiple representor ports under
> >> the same PCI address in the same processe?
> > A PCI device can have multiple physical or representor ports.
> Got it.
> >
> >>>> Would it be more appropriate to do this in rte_eal_cleanup() if it
> >>>> cann't be done in the API above?
> >>> rte_eal_cleanup is a last cleanup for what was not done earlier.
> >>> We could do that but first we should properly free devices when closed.
> >>>
> >> Totally, it is appropriate that rte_eal_cleanup is responsible for
> >> releasing devices under the pci bus.
> > Yes, but if a device is closed while the rest of the app keep running,
> > we should not wait to free it.
> 
>  From this point of view, it seems to make sense. However, according to 
> the OVS-DPDK
> 
> usage, it calls dev_close() first, and then check whether all ports 
> under the PCI address are
> 
> closed to free rte_pci_device by calling rte_dev_remove().
> 
> 
> If we do not want the user to be aware of this, and we want 
> rte_pci_device to be freed
> 
> in a timely manner. Can we add a code logic calculating the number of 
> ports under a PCI address
> 
> and calling rte_dev_remove() to rte_eth_dev_close() to free 
> rte_pci_device and delete it from rte_pci_bus?
> 
> If we do, we may need to make some extra work, otherwise some 
> applications, such as OVS-DPDK, will
> 
> fail due to a second call to rte_dev_remove().

I don't understand the proposal.
Please could explain again the code path?
It may deserve a separate mail thread.