Re: [PATCH v6 net 1/3] ipv6: Remove permanent routes from tb6_gc_hlist when all exceptions expire.

[David Ahern <dsahern@kernel.org>]

On 3/20/26 1:22 AM, Kuniyuki Iwashima wrote:
> Commit 5eb902b8e719 ("net/ipv6: Remove expired routes with a
> separated list of routes.") introduced a per-table GC list and
> changed GC to iterate over that list instead of traversing
> the entire route table.
> 
> However, it forgot to add permanent routes to tb6_gc_hlist
> when exception routes are added.
> 
> Commit cfe82469a00f ("ipv6: add exception routes to GC list
> in rt6_insert_exception") fixed that issue but introduced
> another one.
> 
> Even after all exception routes expire, the permanent routes
> remain in tb6_gc_hlist, potentially negating the performance
> benefits intended by the initial change.
> 
> Let's count gc_args->more before and after rt6_age_exceptions()
> and remove the permanent route when the delta is 0.
> 
> Note that the next patch will reuse fib6_age_exceptions().
> 
> Fixes: cfe82469a00f ("ipv6: add exception routes to GC list in rt6_insert_exception")
> Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
> Reviewed-by: Xin Long <lucien.xin@gmail.com>
> ---
>  net/ipv6/ip6_fib.c | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)
> 

Reviewed-by: David Ahern <dsahern@kernel.org>