Re: [PATCH v3 00/10] Rework vdev probing to use rte_bus infrastructure

On Tue, Feb 28, 2017 at 9:48 AM, Shreyansh Jain [off-list ref] wrote:

On Monday 27 February 2017 06:39 PM, Jan Blunck wrote:

quoted

On Sat, Feb 25, 2017 at 11:28 AM, Jan Blunck [off-list ref]
wrote:

quoted

With the rte_bus infrastructure present in 17.02 it is possible to
refactor
the virtual device probing into a bus. This series also introduces the
rte_vdev_device to better keep track of devices.

This patchset depends on:
http://dpdk.org/dev/patchwork/patch/20416/
http://dpdk.org/dev/patchwork/patch/20417/

Changes since version 2:
 * implicit bus registration through rte_eal_vdrv_register()

On a second thought I don't think that this is correct though since it
opens up the possibility of racing an alternative "virtual" bus. I
don't think that this is a good thing though. I'll fix this in v4.

Thoughts?

I prefer the RTE_REGISTER* way.
The issue of duplicate bus remains whether we use the macro or the
implicit way.

If you use RTE_*, do you think that duplicate registration issue
is worth fixing?
(It would mean rte_bus_register to return error which the caller
would then need to handle).

I don't think that there is a good way to handle this if we use the
library constructors. It is better to fail the registration of the bus
and log the error via RTE_LOG(). That introduces a dependency on the
initialization of the logging system to be available before the
library constructors run (before main()).