On Fri, Apr 19, 2019 at 2:04 PM William Tu <[email protected]> wrote: > > When testing packet rate around 1Mpps with meter enabled, the frequency > of hitting meter action becomes much higher, around 30us each time. > As a result, the meter's calculation of 'uint32_t delta_t' becomes > always 0 and meter action has no effect. This is due to the previous > commit 05f9e707e194 divides the delta by 1000, in order to convert to > msec granularity. The patch fixes it updating the time when across > millisecond boundary. > > Fixes: 05f9e707e194 ("dpif-netdev: Use microsecond granularity.") > Cc: Ilya Maximets <[email protected]> > Cc: Yi-Hung Wei <[email protected]> > Signed-off-by: William Tu <[email protected]> > --- > lib/dpif-netdev.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c > index c20f875ee097..7a572df641f6 100644 > --- a/lib/dpif-netdev.c > +++ b/lib/dpif-netdev.c > @@ -5549,7 +5549,7 @@ dp_netdev_run_meter(struct dp_netdev *dp, struct > dp_packet_batch *packets_, > memset(exceeded_rate, 0, cnt * sizeof *exceeded_rate); > > /* All packets will hit the meter at the same time. */ > - long_delta_t = (now - meter->used) / 1000; /* msec */ > + long_delta_t = now / 1000 - meter->used / 1000; /* msec */ > > /* Make sure delta_t will not be too large, so that bucket will not > * wrap around below. */ > @@ -5557,7 +5557,7 @@ dp_netdev_run_meter(struct dp_netdev *dp, struct > dp_packet_batch *packets_, > ? meter->max_delta_t : (uint32_t)long_delta_t; > > /* Update meter stats. */ > - meter->used = now; > + meter->used = delta_t > 0 ? now : meter->used; Hi William,
Thanks for the patch. I think the check here is not necessary. Without the check here, we can still refill the bucket on every millisecond boundary. Best, -Yi-Hung _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
