On Wed, Jan 04, 2017 at 06:34:40PM +0100, Thomas Monjalon wrote:
> +Cc Sergio (maintainer of the secondary process thing)
>
> 2016-12-28 19:02, Yuanhan Liu:
> > --- a/lib/librte_ether/rte_ethdev.c
> > +++ b/lib/librte_ether/rte_ethdev.c
> > @@ -201,9 +201,6 @@ rte_eth_dev_allocate(const char *name)
> > return NULL;
> > }
> >
> > - if (rte_eth_dev_data == NULL)
> > - rte_eth_dev_data_alloc();
> > -
>
> It is dangerous to move this to rte_eth_dev_pci_probe.
> Please keep it here and duplicate it in eth_dev_attach.
Oh, right, I missed the fact that it could be invoked from other places.
> [...]
> > +/*
> > + * Attach to a port already registered by the primary process, which
> > + * makes sure that the same device would both have the same port id
> > + * in the primary and secondary process.
> > + */
> > +static struct rte_eth_dev *
> > +eth_dev_attach(const char *name)
>
> Maybe that the word "secondary" could help to differentiate of
> the function rte_eth_dev_attach().
Yes, it's better. How about "_attach_secondary", or "_attach_to_primary"?
> > +{
> > + uint8_t i;
> > + struct rte_eth_dev *eth_dev;
> > +
> > + for (i = 0; i < RTE_MAX_ETHPORTS; i++) {
> > + if (strcmp(rte_eth_dev_data[i].name, name) == 0)
> > + break;
> > + }
> > + if (i == RTE_MAX_ETHPORTS) {
> > + RTE_PMD_DEBUG_TRACE(
> > + "device %s is not driven by the primary process\n",
> > + name);
> > + return NULL;
> > + }
> > +
> > + RTE_ASSERT(eth_dev->data->port_id == i);
> > +
> > + eth_dev = &rte_eth_devices[i];
> > + eth_dev->data = &rte_eth_dev_data[i];
> > + eth_dev->attached = DEV_ATTACHED;
> > + nb_ports++;
>
> I am a bit nervous when I see these lines duplicated from
> rte_eth_dev_allocate.
> Not sure whether it deserves a common function or not.
I don't think so, they do share some common assignments, but the assignments
are actually not the same. The primary one has few more: notably, they are:
- eth_dev->data
- eth_dev->data->name
- eth_dev->data->port_id
>
> [...]
> > @@ -246,9 +275,26 @@ rte_eth_dev_pci_probe(struct rte_pci_driver *pci_drv,
> > - eth_dev = rte_eth_dev_allocate(ethdev_name);
> > - if (eth_dev == NULL)
> > - return -ENOMEM;
> > + if (rte_eth_dev_data == NULL)
> > + rte_eth_dev_data_alloc();
> > +
> > + if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
> > + eth_dev = rte_eth_dev_allocate(ethdev_name);
> > + if (eth_dev == NULL)
> > + return -ENOMEM;
> > + } else {
> > + /*
> > + * if we failed to attach a device, it means that
> > + * device is skipped, due to some errors. Take
> > + * virtio-net device as example, it could be the
> > + * device is managed by virtio-net kernel driver.
> > + * For such case, we return a positive value, to
> > + * let EAL skip it as well.
> > + */
>
> This comment (a bit too long) should be placed between "if" and "return".
Okay.
--yliu
