[RFC PATCH dpdk] fib6: implement RCU rule reclamation

[Robin Jarry]

Robin Jarry, Jun 10, 2025 at 16:53:
> Currently, for the TRIE algorithm (actually, it should be called
> DIR-24-8-8-8-8-8-8-8-8-8-8-8-8), the tbl8 group is freed even though the
> readers might be using the tbl8 group entries. The freed tbl8 group can
> be reallocated quickly. As a result, lookup may be performed
> incorrectly.
>
> To address that, RCU QSBR is integrated for safe tbl8 group reclamation.
>
> Cc: Vladimir Medvedkin <vladimir.medvedkin at intel.com>
> Signed-off-by: Robin Jarry <rjarry at redhat.com>
> ---
>
> Notes:
>     This is a semi-copy-paste of the FIB4 implementation.
>     
>     I couldn't understand the implementation of trie_modify with regard to
>     depth_diff handling.
>     
>     The unit tests fail because depth_diff is always 0 when deleting a route
>     which causes any subsequent add to fail with a -ENOSPC error.
>     
>     Vladimir, could you give some more insights on the matter?

Gentle bump. Hi Vladimir, could you have a look? Thanks!

-- 
Robin

> Not recommended for children.