The `mp_cb_registered` flag shared between all processes
was used to ensure that for any IB device (MLX5 common device)
mempool event callback was registered only once
and mempools that had been existing before the device start
were traversed only once to register them.
Since mempool callback registrations have become process-private,
callback registration must be done by every process.
The flag can no longer reflect the state for any single process.
Replace it with a registration counter to track
when no more callbacks are registered for the device in any process.
It is sufficient to only register pre-existing mempools
in the primary process because it is the one that starts the device.
Fixes: 690b2a88c2 ("common/mlx5: add mempool registration facilities")
Cc: stable@dpdk.org
Signed-off-by: Dmitry Kozlyuk <dkozlyuk@nvidia.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
8ad97e4b32