On Sunday, December 11, 2016 11:43:59 AM CET Pablo Neira Ayuso wrote:
> Dump and reset doesn't work unless cmpxchg64() is used both from packet
> and control plane paths. This approach is going to be slow though.
> Instead, use a percpu seqcount to fetch counters consistently, then
> subtract bytes and packets in case a reset was requested.
>
> The cpu that running over the reset code is guaranteed to own this stats
> exclusively, we have to turn counters into signed 64bit though so stats
> update on reset don't get wrong on underflow.
>
> This patch is based on original sketch from Eric Dumazet.
>
> Fixes: 43da04a593d8 ("netfilter: nf_tables: atomic dump and reset for
> stateful objects")
> Suggested-by: Eric Dumazet <eric.duma...@gmail.com>
> Signed-off-by: Pablo Neira Ayuso <pa...@netfilter.org>
>
Looks great, I had a similar idea that I was going to suggest the
other day, but yours is better anyway.
Arnd
