[dpdk-dev] [PATCH v11 01/19] ethdev: add function to release port in local process

[Zhang, Qi Z]

> -----Original Message-----
> From: Andrew Rybchenko [mailto:arybchenko at solarflare.com]
> Sent: Thursday, July 12, 2018 12:05 AM
> To: Zhang, Qi Z <qi.z.zhang at intel.com>; thomas at monjalon.net; Burakov,
> Anatoly <anatoly.burakov at intel.com>
> Cc: Ananyev, Konstantin <konstantin.ananyev at intel.com>; dev at dpdk.org;
> Richardson, Bruce <bruce.richardson at intel.com>; Yigit, Ferruh
> <ferruh.yigit at intel.com>; Shelton, Benjamin H
> <benjamin.h.shelton at intel.com>; Vangati, Narender
> <narender.vangati at intel.com>
> Subject: Re: [dpdk-dev] [PATCH v11 01/19] ethdev: add function to release port
> in local process
> 
> On 11.07.2018 15:30, Zhang, Qi Z wrote:
> >
> >> -----Original Message-----
> >> From: Andrew Rybchenko [mailto:arybchenko at solarflare.com]
> >> Sent: Wednesday, July 11, 2018 5:27 PM
> >> To: Zhang, Qi Z <qi.z.zhang at intel.com>; thomas at monjalon.net; Burakov,
> >> Anatoly <anatoly.burakov at intel.com>
> >> Cc: Ananyev, Konstantin <konstantin.ananyev at intel.com>; dev at dpdk.org;
> >> Richardson, Bruce <bruce.richardson at intel.com>; Yigit, Ferruh
> >> <ferruh.yigit at intel.com>; Shelton, Benjamin H
> >> <benjamin.h.shelton at intel.com>; Vangati, Narender
> >> <narender.vangati at intel.com>
> >> Subject: Re: [dpdk-dev] [PATCH v11 01/19] ethdev: add function to
> >> release port in local process
> >>
> >> On 11.07.2018 06:08, Qi Zhang wrote:
> >>> Add driver API rte_eth_release_port_private to support the case when
> >>> an ethdev need to be detached on a secondary process.
> >>> Local state is set to unused and shared data will not be reset so
> >>> the primary process can still use it.
> >>>
> >>> Signed-off-by: Qi Zhang <qi.z.zhang at intel.com>
> >>> Reviewed-by: Andrew Rybchenko <arybchenko at solarflare.com>
> >>> Acked-by: Remy Horton <remy.horton at intel.com>
> >>> ---
> > <...>
> >>> +	/**
> >>> +	 * PCI device can only be globally detached directly by a
> >>> +	 * primary process. In secondary process, we only need to
> >>> +	 * release port.
> >>> +	 */
> >>> +	if (rte_eal_process_type() != RTE_PROC_PRIMARY)
> >>> +		return rte_eth_dev_release_port_private(eth_dev);
> >> I've realized that some uninit functions which will not be called
> >> anymore in secondary processes have check for process type and
> >> handling of secondary process case. It makes code inconsistent and should
> be fixed.
> > Good point, I did a scan and check all the places that
> rte_eth_dev_pci_generic_remove be involved.
> > I found only sfc driver (sfc_eth_dev_unit) will call some cleanup on
> secondary process as below.
> 
> The patch makes impossible dev_uninit to be executed for secondary process
> for all cases if rte_eth_dev_pci_generic_remove() is used. However, many
> drivers still check for process type. Yes, sfc does cleanup, but some drivers
> return -EPERM, some return 0. In fact it does not matter. It leaves dead code
> which is really confusing.

OK, l can do a cleanup in a separate patchset if this one will be merged.

> 
> >
> > 		if (rte_eal_process_type() != RTE_PROC_PRIMARY) {
> >                  sfc_eth_dev_secondary_clear_ops(dev);
> >                  return 0;
> >          }
> >
> > But in sfc_eth_dev_secondary_clear_ops
> >
> > static void
> > sfc_eth_dev_secondary_clear_ops(struct rte_eth_dev *dev) {
> >          dev->dev_ops = NULL;
> >          dev->tx_pkt_burst = NULL;
> >          dev->rx_pkt_burst = NULL;
> > }
> >
> > So my understand is current change is not a problem for all exist drivers.
> >
> > Please let me know if I missed something
> >
> > Thanks
> > Qi
> >
> >>> +
> >>>    	if (dev_uninit) {
> >>>    		ret = dev_uninit(eth_dev);
> >>>    		if (ret)