Re: [PATCH bpf-next v5 0/6] xdp: Add devmap_hash map type

["Toke Høiland-Jørgensen" <toke@redhat.com>]

Alexei Starovoitov <alexei.starovoitov@gmail.com> writes:

> On Fri, Jul 26, 2019 at 9:06 AM Toke Høiland-Jørgensen <toke@redhat.com> wrote:
>>
>> This series adds a new map type, devmap_hash, that works like the existing
>> devmap type, but using a hash-based indexing scheme. This is useful for the use
>> case where a devmap is indexed by ifindex (for instance for use with the routing
>> table lookup helper). For this use case, the regular devmap needs to be sized
>> after the maximum ifindex number, not the number of devices in it. A hash-based
>> indexing scheme makes it possible to size the map after the number of devices it
>> should contain instead.
>>
>> This was previously part of my patch series that also turned the regular
>> bpf_redirect() helper into a map-based one; for this series I just pulled out
>> the patches that introduced the new map type.
>>
>> Changelog:
>>
>> v5:
>>
>> - Dynamically set the number of hash buckets by rounding up max_entries to the
>>   nearest power of two (mirroring the regular hashmap), as suggested by Jesper.
>
> fyi I'm waiting for Jesper to review this new version.

Ping Jesper? :)

-Toke