rte_eth_dev_count_avail returns different value in library

[Dmitry Kozlyuk]

2022-10-28 09:45 (UTC+0000), Robert Hable:
> Hello,
> 
> I am trying to build a static library based on the skeleton example. My problem is when calling rte_eth_dev_count_avail() I always receive 0 in the static library. When I start the skeleton example app as a regular exe file, then it returns 2.
> What could be the reason that rte_eth_dev_count_avail() returns different values depending on if it is an exe application or a static library?
> 
> rte_eal_init() is called in both applications with the default parameters.
> Both processes are running under the same administrator user.
> 
> I am using Windows Server 2022 with a Mellanox ConnectX-4 on DPDK V 22.11.0-rc0.
> 
> Kind regards,
> Robert Hable
> 

Hi Robert,

Are you building DPDK as static libraries?
Shared build is currently non-functional on Windows.

If so, are you linking PMD libraries (librte_common_mlx5, librte_net_mlx5)
to the application that is using your static library?
If relevant PMD libraries are not linked, HW will not be discovered
(same for mempools BTW).

It is irrelevant from where rte_eth_dev_count_avail() is called,
but please check that in both cases it is done after rte_eal_init().