On 22 Dec 2022, at 10:26, Balazs Nemeth wrote:
> The only way that stats->{n_packets,n_bytes} would decrease is due to an
> overflow, or if there are bugs in how statistics are handled. In the
> past, there were multiple bugs that caused a jump backward. A
> workaround was in place to set the statistics to 0 in that case. When
> this happened while the revalidator was under heavy load, the workaround
> had an unintended side effect where should_revalidate returned false
> causing the flow to be removed because the metric it calculated was
> based on a bogus value. Since many of those bugs have now been
> identified and resolved, there is no need to set the statistics to 0. In
> addition, the (unlikely) overflow still needs to be handled
> appropriately.
>
> Signed-off-by: Balazs Nemeth <[email protected]>
> ---
>
> Depends on:
> - netdev-offload-tc: Preserve tc statistics when flow gets modified.
> - tc: Add support for TCA_STATS_PKT64
> - ofproto-dpif-upcall: Wait for valid hw flow stats before applying
> min-revalidate-pps
> - ofproto-dpif-upcall: Use last known stats ukey stats on revalidate missed
> dp flows.
Did a lot of tests with this patch applied, but as mentioned it does need all
four patches mentioned above applied first.
Acked-by: Eelco Chaudron <[email protected]>
> ofproto/ofproto-dpif-upcall.c | 8 ++------
> 1 file changed, 2 insertions(+), 6 deletions(-)
>
> diff --git a/ofproto/ofproto-dpif-upcall.c b/ofproto/ofproto-dpif-upcall.c
> index ad9635496..9117a1aef 100644
> --- a/ofproto/ofproto-dpif-upcall.c
> +++ b/ofproto/ofproto-dpif-upcall.c
> @@ -2334,12 +2334,8 @@ revalidate_ukey(struct udpif *udpif, struct udpif_key
> *ukey,
>
> push.used = stats->used;
> push.tcp_flags = stats->tcp_flags;
> - push.n_packets = (stats->n_packets > ukey->stats.n_packets
> - ? stats->n_packets - ukey->stats.n_packets
> - : 0);
> - push.n_bytes = (stats->n_bytes > ukey->stats.n_bytes
> - ? stats->n_bytes - ukey->stats.n_bytes
> - : 0);
> + push.n_packets = stats->n_packets - ukey->stats.n_packets;
> + push.n_bytes = stats->n_bytes - ukey->stats.n_bytes;
>
> if (need_revalidate) {
> if (should_revalidate(udpif, push.n_packets, ukey->stats.used)) {
> --
> 2.38.1
_______________________________________________
dev mailing list
[email protected]
https://mail.openvswitch.org/mailman/listinfo/ovs-dev
