Re: [PATCHv6 bpf-next 1/3] xdp: add a new helper for dev map multicast support

David Ahern
2020-07-11T16:09:35Z

On 7/10/20 6:26 PM, Hangbin Liu wrote:
>>
>> The point of DEVMAP_HASH is to allow map management where key == device
>> index (vs DEVMAP which for any non-trivial use case is going to require
>> key != device index). You could require the exclude map to be
>> DEVMAP_HASH and the key to be the index allowing you to do a direct
>> lookup. Having to roam the entire map looking for a match does not scale
>> and is going to have poor performance with increasing number of entries.
>> XDP is targeted at performance with expert level of control, so
>> constraints like this have to be part of the deal.
>
> Yes, if we have this constraints the performance should have some improvement.
>
> Do you think we should do it right now or in later performance update patch.
>

It needs to be in the same release as the initial patches. Easiest to
include with the initial set, but a followup is fine if it happens
before this dev cycle is over.