* [dpdk-dev] [PATCH v2] lib/librte_meter: fix divide by zero for RFC4115 meter
@ 2019-02-01 16:07 Eelco Chaudron
2019-02-05 8:40 ` Jens Freimann
2019-02-28 18:50 ` Dumitrescu, Cristian
0 siblings, 2 replies; 5+ messages in thread
From: Eelco Chaudron @ 2019-02-01 16:07 UTC (permalink / raw)
To: cristian.dumitrescu; +Cc: dev
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: echaudro@redhat.com
Signed-off-by: Eelco Chaudron <echaudro@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;
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [dpdk-dev] [PATCH v2] lib/librte_meter: fix divide by zero for RFC4115 meter
2019-02-01 16:07 [dpdk-dev] [PATCH v2] lib/librte_meter: fix divide by zero for RFC4115 meter Eelco Chaudron
@ 2019-02-05 8:40 ` Jens Freimann
2019-02-28 18:50 ` Dumitrescu, Cristian
1 sibling, 0 replies; 5+ messages in thread
From: Jens Freimann @ 2019-02-05 8:40 UTC (permalink / raw)
To: Eelco Chaudron; +Cc: cristian.dumitrescu, dev
On Fri, Feb 01, 2019 at 04:07:16PM +0000, Eelco Chaudron wrote:
>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: echaudro@redhat.com
>
>Signed-off-by: Eelco Chaudron <echaudro@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(-)
>
Reviewed-by: Jens Freimann <jfreimann@redhat.com>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [dpdk-dev] [PATCH v2] lib/librte_meter: fix divide by zero for RFC4115 meter
2019-02-01 16:07 [dpdk-dev] [PATCH v2] lib/librte_meter: fix divide by zero for RFC4115 meter Eelco Chaudron
2019-02-05 8:40 ` Jens Freimann
@ 2019-02-28 18:50 ` Dumitrescu, Cristian
2019-03-19 11:00 ` Eelco Chaudron
1 sibling, 1 reply; 5+ messages in thread
From: Dumitrescu, Cristian @ 2019-02-28 18:50 UTC (permalink / raw)
To: Eelco Chaudron; +Cc: dev
Hi Eelco,
Sorry for my delayed reply,
> -----Original Message-----
> From: Eelco Chaudron [mailto:echaudro@redhat.com]
> Sent: Friday, February 1, 2019 4:07 PM
> To: Dumitrescu, Cristian <cristian.dumitrescu@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: echaudro@redhat.com
>
> Signed-off-by: Eelco Chaudron <echaudro@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
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [dpdk-dev] [PATCH v2] lib/librte_meter: fix divide by zero for RFC4115 meter
2019-02-28 18:50 ` Dumitrescu, Cristian
@ 2019-03-19 11:00 ` Eelco Chaudron
2019-03-19 11:00 ` Eelco Chaudron
0 siblings, 1 reply; 5+ messages in thread
From: Eelco Chaudron @ 2019-03-19 11:00 UTC (permalink / raw)
To: Dumitrescu, Cristian; +Cc: dev
On 28 Feb 2019, at 19:50, Dumitrescu, Cristian wrote:
> Hi Eelco,
>
> Sorry for my delayed reply
No problem I was OOO also so hence my late reply ;)
>> -----Original Message-----
>> From: Eelco Chaudron [mailto:echaudro@redhat.com]
>> Sent: Friday, February 1, 2019 4:07 PM
>> To: Dumitrescu, Cristian <cristian.dumitrescu@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: echaudro@redhat.com
>>
>> Signed-off-by: Eelco Chaudron <echaudro@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.
Excellent idea, will sent out a v3 soon, after some testing…
//Eelco
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [dpdk-dev] [PATCH v2] lib/librte_meter: fix divide by zero for RFC4115 meter
2019-03-19 11:00 ` Eelco Chaudron
@ 2019-03-19 11:00 ` Eelco Chaudron
0 siblings, 0 replies; 5+ messages in thread
From: Eelco Chaudron @ 2019-03-19 11:00 UTC (permalink / raw)
To: Dumitrescu, Cristian; +Cc: dev
On 28 Feb 2019, at 19:50, Dumitrescu, Cristian wrote:
> Hi Eelco,
>
> Sorry for my delayed reply
No problem I was OOO also so hence my late reply ;)
>> -----Original Message-----
>> From: Eelco Chaudron [mailto:echaudro@redhat.com]
>> Sent: Friday, February 1, 2019 4:07 PM
>> To: Dumitrescu, Cristian <cristian.dumitrescu@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: echaudro@redhat.com
>>
>> Signed-off-by: Eelco Chaudron <echaudro@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.
Excellent idea, will sent out a v3 soon, after some testing…
//Eelco
^ permalink raw reply [flat|nested] 5+ messages in thread
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2019-02-01 16:07 [dpdk-dev] [PATCH v2] lib/librte_meter: fix divide by zero for RFC4115 meter Eelco Chaudron
2019-02-05 8:40 ` Jens Freimann
2019-02-28 18:50 ` Dumitrescu, Cristian
2019-03-19 11:00 ` Eelco Chaudron
2019-03-19 11:00 ` Eelco Chaudron
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