[dpdk-dev] meter: excess token bucket update in srtcm

Nikhil Jagtap nikhil.jagtap at gmail.com
Tue Sep 6 08:29:39 CEST 2016


Hi Kannan,

Thank you for your reply. I will submit the patch on similar lines I had
used for my test.

Regards,
Nikhil

On 6 September 2016 at 10:40, Ramia, Kannan Babu <
kannan.babu.ramia at intel.com> wrote:

> Hi Nikhil
>
> You could submit a patch, something like that below logic
>
> If( ((n_periods * m->cir_bytes_per_period) > (m->cbs-m->tc))
>         te = m->te + ((n_periods * m->cir_bytes_per_period) -
> (m->cbs-m->tc));
>
> and this should be done before m->tc update.
>
>
> Regards
> Kannan Babu
>
> -----Original Message-----
> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Nikhil Jagtap
> Sent: Tuesday, September 6, 2016 9:43 AM
> To: Dumitrescu, Cristian <cristian.dumitrescu at intel.com>
> Cc: dev at dpdk.org
> Subject: Re: [dpdk-dev] meter: excess token bucket update in srtcm
>
> Hi,
> Can someone please comment on this?
>
> Nikhil
>
> On 31 August 2016 at 15:32, Nikhil Jagtap <nikhil.jagtap at gmail.com> wrote:
>
> > Hi,
> >
> > As per srTCM RFC 2697, we should be updating the E bucket only after
> > the C bucket overflows.
> > "Thereafter, the token counts Tc and Te are updated CIR times per
> > second as follows:
> >      o If Tc is less than CBS, Tc is incremented by one, else
> >      o if Te is less then EBS, Te is incremented by one, else
> >      o neither Tc nor Te is incremented."
> >
> > However in the current DPDK implementation of srTCM, we are updating
> > both the buckets simultaneously at the same rate (CIR). This will
> > result in a token accumulation rate of (2*CIR). This seems like a bug
> > to me. Can you confirm this?
> >
> > Nikhil
> >
> >
>


More information about the dev mailing list