Re: [dpdk-dev] [PATCH] ethdev: add namespace

[David Marchand <david.marchand@redhat.com>]

Hello Ferruh,

On Tue, Jun 29, 2021 at 3:46 PM Ferruh Yigit <ferruh.yigit@intel.com> wrote:
>
> Add 'RTE_ETH' namespace to all enums & macros in a backward compatible
> way. The macros for backward compatibility can be removed in next LTS.
>
> Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>

- I did not do a full check but I noticed that ETH_RSS compat macro at
least is removed.
Is this intentional?


- libabigail is not happy because of enum names changes.
Example:

  [C] 'function int rte_eth_dev_configure(uint16_t, uint16_t,
uint16_t, const rte_eth_conf*)' at rte_ethdev.c:1326:1 has some
indirect sub-type changes:
    parameter 4 of type 'const rte_eth_conf*' has sub-type changes:
      in pointed to type 'const rte_eth_conf':
        in unqualified underlying type 'struct rte_eth_conf' at
rte_ethdev.h:1491:1:
          type size hasn't changed
          5 data member changes (1 filtered):
            type of 'rte_eth_rxmode rxmode' changed:
              type size hasn't changed
              1 data member change:
                type of 'rte_eth_rx_mq_mode mq_mode' changed:
                  type size hasn't changed
                  8 enumerator deletions:
                    'rte_eth_rx_mq_mode::ETH_MQ_RX_NONE' value '0'
                    'rte_eth_rx_mq_mode::ETH_MQ_RX_RSS' value '1'
                    'rte_eth_rx_mq_mode::ETH_MQ_RX_DCB' value '2'
                    'rte_eth_rx_mq_mode::ETH_MQ_RX_DCB_RSS' value '3'
                    'rte_eth_rx_mq_mode::ETH_MQ_RX_VMDQ_ONLY' value '4'
                    'rte_eth_rx_mq_mode::ETH_MQ_RX_VMDQ_RSS' value '5'
                    'rte_eth_rx_mq_mode::ETH_MQ_RX_VMDQ_DCB' value '6'
                    'rte_eth_rx_mq_mode::ETH_MQ_RX_VMDQ_DCB_RSS' value '7'
                  8 enumerator insertions:
                    'rte_eth_rx_mq_mode::RTE_ETH_MQ_RX_NONE' value '0'
                    'rte_eth_rx_mq_mode::RTE_ETH_MQ_RX_RSS' value '1'
                    'rte_eth_rx_mq_mode::RTE_ETH_MQ_RX_DCB' value '2'
                    'rte_eth_rx_mq_mode::RTE_ETH_MQ_RX_DCB_RSS' value '3'
                    'rte_eth_rx_mq_mode::RTE_ETH_MQ_RX_VMDQ_ONLY' value '4'
                    'rte_eth_rx_mq_mode::RTE_ETH_MQ_RX_VMDQ_RSS' value '5'
                    'rte_eth_rx_mq_mode::RTE_ETH_MQ_RX_VMDQ_DCB' value '6'
                    'rte_eth_rx_mq_mode::RTE_ETH_MQ_RX_VMDQ_DCB_RSS' value '7'
[snip]


I guess libabigail is lost because the symbol
rte_eth_rx_mq_mode::ETH_MQ_RX_NONE simply disappeared (because we used
a macro to wrap to the new name).
Maybe we could go the other way: leave the current enums defined as is
and put in place wrappers for new names pointing as old names.
The rest of the code in DPDK would use the new names only.
This comment applies if we want to merge this change in 21.08 and/or
we want to backport this change.

This won't be a problem if we merge this patch in 21.11.


> ---
> We can get the update on v21.11 and remove backward compatibility macros
> on v22.11.



-- 
David Marchand