16/09/2021 10:01, Huisong Li: > 在 2021/9/8 15:20, Thomas Monjalon 写道: > > 08/09/2021 04:01, Huisong Li: > >> 在 2021/9/7 16:53, Thomas Monjalon 写道: > >>> 07/09/2021 05:41, Huisong Li: > >>>> Calling rte_eth_dev_close() will release resources of eth device and > >>>> close > >>>> it. But rte_pci_device struct isn't released when app exit, which will > >>>> lead > >>>> to memory leak. > >>> That's a PMD issue. > >>> When the last port of a PCI device is closed, the device should be freed. > >> Why is this a PMD problem? I don't understand. > > > > In the PMD close function, freeing of PCI device must be managed, > > so the app doesn't have to bother. > > I know what you mean. Currently, there are two ways to close PMD device > (rte_eth_dev_close() and rte_dev_remove()). > > For rte_dev_remove(), eth device can be closed and rte_pci_device also > can be freed, so it can make app not care about that. > > But dev_close() is only used to close eth device, and nothing about > rte_pci_device is involved in the framework layer > > call stack of dev_close(). The rte_pci_device is allocated and > initialized when the rte_pci_bus scans "/sys/bus/pci/devices" directory. > > Generally, the PMD of eth devices operates on the basis of eth devices, > and rarely on rte_pci_device.
No. The PMD is doing the relation between the PCI device and the ethdev port. > And the rte_pci_device corresponding to the eth devices managed and > processed by rte_pci_bus. > > So, PMD is closed only based on the port ID of the eth device, whilch > only shuts down eth devices, not frees rte_pci_device > and remove it from rte_pci_bus. Not really. If there is no port using the PCI device, it should be released. > >> As far as I know, most apps or examples in the DPDK project have only > >> one port for a pci device. > > The number of ports per PCI device is driver-specific. > > > >> When the port is closed, the rte_pci_device should be freed. But none of > >> the apps seem to do this. > > > > That's because from the app point of view, only ports should be managed. > > The hardware device is managed by the PMD. > > Only drivers (PMDs) have to do the relation between class ports > > and hardware devices. > > Yes. But the current app only closes the port to disable the PMD, and > the rte_pci_device cannot be freed. Why not? > Because rte_pci_device cannot be released in dev_close() of PMD, and is > managed by framework layer. No > Btw. Excluding rte_dev_probe() and rte_dev_remove(), it seems that the > DPDK framework only automatically > scans PCI devices, but does not automatically release PCI devices when > the process exits. Indeed, because such freeing is the responsibility of the PMD.
