Re: [dpdk-dev] Making rte_eal_pci_probe() in rte_eal_init() optional?

[David Marchand <david.marchand@6wind.com>]

Hello Roger,

On Thu, Nov 12, 2015 at 11:43 PM, Roger B Melton <rmelton@cisco.com> wrote:

> Hi folks,
>
> With the addition of hot plug support we have been migrating away from
> device discovery and attach at initialization time to a model where it is
> controlled from a separate process.  The separate process manages the
> binding of devices to UIO and instructs the DPDK process when to attach.
> One of the problems we stumbled onto was that if our control process
> discovered devices and bound them to UIO before our DPDK process started,
> then rte_eal_init() would discover and attach to those devices via the
> rte_eal_pci_probe() invocation. This caused problems later on when when our
> control process, instructed our DPDK process to attach to a device.
>
> There are a number of ways we could address this, but the simplest is to
> prevent the rte_eal_pci_probe() at rte_eal_init() time.  In our model we
> will never need it and I suspect others may also be in that boat.
>
> What are your thoughts on adding an argument to instruct rte_eal_init() to
> skip the PCI probe?
>

Did you try the --no-pci option ?
It avoids the initial sysfs scan, so with no pci device, the initial
pci_probe should do nothing.

Attaching devices later will trigger this sysfs scan and only probe the
requested device.
I am not totally happy with the way it is done right now, but I think this
should work for you.


-- 
David Marchand