[dpdk-dev] rte_flow ageing

[David Bouyeure]

Sorry for the below topic confusion(in-reply-to).

On 3/29/21 9:50 AM, David Bouyeure wrote:
> Hi,
>
>
> I've found out the pretty useful experimental brand new flow ageing 
> API implemented in the mlx5 PMD.
>
> I'm trying it (rte_eth_dev_callback_register(RTE_ETH_EVENT_FLOW_AGED), 
> RTE_FLOW_ACTION_TYPE_AGE) to recover any flow that I previously 
> offloaded.
>
> The DPDK version is 20.08 and Mellanox(Connect-X6) OFED drivers are 
> 5.1-2.5.8.0.
>
> I eventually don't see the usefulness of the callback since it's 
> actually triggered indirectly by us(the DPDK application) when calling 
> rte_flow_get_aged_flows(). If we don't call it, the callback is called 
> only once.
>
> And, calling rte_flow_get_aged_flows() from the callback won't trigger 
> it next time(MLX5_AGE_TRIGGER is reset after the callback call)
>
> Furthermore, I don't see the point of computing ageing flows in 
> mlx5_fow.c::mlx5_flow_aging_check() if the client callback isn't called.
>
> So far, I can handle the flow ageing from the same thread as the one 
> which is handling the flow direction(rte_flow), it even avoid threads 
> synchronization. But, in the future, I may need to be noticed as soon 
> as possible of a single flow ageing, and thus handle this flow logic 
> from the ageing callback.
>
>
> I may misunderstand the whole ageing API... Thanks a lot for any 
> clarification.
>