Hi Eelco, Sorry for my delayed reply,
> -----Original Message----- > From: Eelco Chaudron [mailto:echau...@redhat.com] > Sent: Friday, February 1, 2019 4:07 PM > To: Dumitrescu, Cristian <cristian.dumitre...@intel.com> > Cc: dev@dpdk.org > Subject: [PATCH v2] lib/librte_meter: fix divide by zero for RFC4115 meter > > RFC 4115 allows a meter with either cir and/or eir configured. > When only one is configured a divide by zero would occur. > > Fixes: 655796d2b5fb ("meter: support RFC4115 trTCM") > Cc: echau...@redhat.com > > Signed-off-by: Eelco Chaudron <echau...@redhat.com> > --- > > v2 - Removed configuration change that got included by accident > > lib/librte_meter/rte_meter.h | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/lib/librte_meter/rte_meter.h b/lib/librte_meter/rte_meter.h > index 005e4eeee..56d85ecf0 100644 > --- a/lib/librte_meter/rte_meter.h > +++ b/lib/librte_meter/rte_meter.h > @@ -597,8 +597,8 @@ rte_meter_trtcm_rfc4115_color_blind_check( > /* Bucket update */ > time_diff_tc = time - m->time_tc; > time_diff_te = time - m->time_te; > - n_periods_tc = time_diff_tc / p->cir_period; > - n_periods_te = time_diff_te / p->eir_period; > + n_periods_tc = p->cir_period != 0 ? time_diff_tc / p->cir_period : 0; > + n_periods_te = p->eir_period != 0 ? time_diff_te / p->eir_period : 0; > m->time_tc += n_periods_tc * p->cir_period; > m->time_te += n_periods_te * p->eir_period; > > @@ -641,8 +641,8 @@ rte_meter_trtcm_rfc4115_color_aware_check( > /* Bucket update */ > time_diff_tc = time - m->time_tc; > time_diff_te = time - m->time_te; > - n_periods_tc = time_diff_tc / p->cir_period; > - n_periods_te = time_diff_te / p->eir_period; > + n_periods_tc = p->cir_period != 0 ? time_diff_tc / p->cir_period : 0; > + n_periods_te = p->eir_period != 0 ? time_diff_te / p->eir_period : 0; > m->time_tc += n_periods_tc * p->cir_period; > m->time_te += n_periods_te * p->eir_period; > Yes, this is indeed an issue, good catch! For performance reasons, we'd like to avoid a test on the fast path (rte_meter_xyz_check) and replace it with more work done on the configuration stage (rte_meter_profile_xyz_config), if possible. We can intercept the null CIR or EIR cases very early in rte_meter_trtcm_rfc4115_profile_config() and deal with them separately by setting the CIR/EIR period and bytes_per_period to some neutral values and skipping the call to rte_meter_get_tb_params(): period = RTE_METER_TB_PERIOD_MIN, bytes_per_period = 0. Makes sense? Regards, Cristian
