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number of pipelines for different models

V
verdi@ufscar.br
Mon, May 31, 2021 10:09 AM

Hello all,

I tried to find this answer through the list but didn’t succeed to have a clear answer.

The number of pipelines for PSA is 4. This is defined in the specification. However, I am wondering home many pipelines v1model has. I read somewhere here in the list that it is 2. That is correct? If yes, where such info is defined?

Best,

Fábio.

Hello all, I tried to find this answer through the list but didn’t succeed to have a clear answer. The number of pipelines for PSA is 4. This is defined in the specification. However, I am wondering home many pipelines v1model has. I read somewhere here in the list that it is 2. That is correct? If yes, where such info is defined? Best, Fábio.
AF
Andy Fingerhut
Tue, Jun 1, 2021 12:56 PM

You say "The number of pipelines for PSA is 4.  This is defined in the
specification."

Can you give a quote from the PSA specification, and what section number
the quote is from, that you got this from?

In particular, what do you mean when you say "pipeline"?  Do you mean
ingress is one pipeline, and egress is another pipeline?  In that sense of
the word "pipeline", both PSA and v1model have 2 pipelines.

If you mean something else where PSA has 4 of those things, I do not have a
guess what you mean yet, hence my question above.

Andy

On Mon, May 31, 2021 at 6:10 AM verdi@ufscar.br wrote:

Hello all,

I tried to find this answer through the list but didn’t succeed to have a
clear answer.

The number of pipelines for PSA is 4. This is defined in the
specification. However, I am wondering home many pipelines v1model has. I
read somewhere here in the list that it is 2. That is correct? If yes,
where such info is defined?

Best,

Fábio.


P4-dev mailing list -- p4-dev@lists.p4.org
To unsubscribe send an email to p4-dev-leave@lists.p4.org
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You say "The number of pipelines for PSA is 4. This is defined in the specification." Can you give a quote from the PSA specification, and what section number the quote is from, that you got this from? In particular, what do you mean when you say "pipeline"? Do you mean ingress is one pipeline, and egress is another pipeline? In that sense of the word "pipeline", both PSA and v1model have 2 pipelines. If you mean something else where PSA has 4 of those things, I do not have a guess what you mean yet, hence my question above. Andy On Mon, May 31, 2021 at 6:10 AM <verdi@ufscar.br> wrote: > Hello all, > > I tried to find this answer through the list but didn’t succeed to have a > clear answer. > > The number of pipelines for PSA is 4. This is defined in the > specification. However, I am wondering home many pipelines v1model has. I > read somewhere here in the list that it is 2. That is correct? If yes, > where such info is defined? > > Best, > > Fábio. > _______________________________________________ > P4-dev mailing list -- p4-dev@lists.p4.org > To unsubscribe send an email to p4-dev-leave@lists.p4.org > %(web_page_url)slistinfo%(cgiext)s/%(_internal_name)s
FL
Fabio Luciano Verdi
Tue, Jun 1, 2021 1:10 PM

Hi Andy,
I am talking about Section "E. Appendix: Multi-pipeline PSA devices" of PSA
Spec. However, I don't know from where I concluded that PSA has defined 4
pipelines. I think that is because I was reading (and working with) the
Tofino specs and that one has 4 pipelines.
And pipelines here are not meant to be ingress or egress, although it seems
that the same word is used for different contexts. Pipeline here means the
"physical" division of (physical) ports as is explained in the Appendix E
that I mentioned. Lets again use Tofino as our baseline. A Tofino switch
with 64 ports and 4 "pipelines" arranges 16 ports in each "pipeline".
So, my question is how many of those "pipelines" v1 model has or supports.
Sorry for the confusion.
Best,
Fábio.

Em ter., 1 de jun. de 2021 às 14:56, Andy Fingerhut <
andy.fingerhut@gmail.com> escreveu:

You say "The number of pipelines for PSA is 4.  This is defined in the
specification."

Can you give a quote from the PSA specification, and what section number
the quote is from, that you got this from?

In particular, what do you mean when you say "pipeline"?  Do you mean
ingress is one pipeline, and egress is another pipeline?  In that sense of
the word "pipeline", both PSA and v1model have 2 pipelines.

If you mean something else where PSA has 4 of those things, I do not have
a guess what you mean yet, hence my question above.

Andy

On Mon, May 31, 2021 at 6:10 AM verdi@ufscar.br wrote:

Hello all,

I tried to find this answer through the list but didn’t succeed to have a
clear answer.

The number of pipelines for PSA is 4. This is defined in the
specification. However, I am wondering home many pipelines v1model has. I
read somewhere here in the list that it is 2. That is correct? If yes,
where such info is defined?

Best,

Fábio.


P4-dev mailing list -- p4-dev@lists.p4.org
To unsubscribe send an email to p4-dev-leave@lists.p4.org
%(web_page_url)slistinfo%(cgiext)s/%(_internal_name)s

--

Associate Prof. Fábio Luciano Verdi (UFSCar)

Research Visitor at KTH - 2021-2022

http://www.dcomp.ufscar.br/verdi/

Hi Andy, I am talking about Section "E. Appendix: Multi-pipeline PSA devices" of PSA Spec. However, I don't know from where I concluded that PSA has defined 4 pipelines. I think that is because I was reading (and working with) the Tofino specs and that one has 4 pipelines. And pipelines here are not meant to be ingress or egress, although it seems that the same word is used for different contexts. Pipeline here means the "physical" division of (physical) ports as is explained in the Appendix E that I mentioned. Lets again use Tofino as our baseline. A Tofino switch with 64 ports and 4 "pipelines" arranges 16 ports in each "pipeline". So, my question is how many of those "pipelines" v1 model has or supports. Sorry for the confusion. Best, Fábio. Em ter., 1 de jun. de 2021 às 14:56, Andy Fingerhut < andy.fingerhut@gmail.com> escreveu: > You say "The number of pipelines for PSA is 4. This is defined in the > specification." > > Can you give a quote from the PSA specification, and what section number > the quote is from, that you got this from? > > In particular, what do you mean when you say "pipeline"? Do you mean > ingress is one pipeline, and egress is another pipeline? In that sense of > the word "pipeline", both PSA and v1model have 2 pipelines. > > If you mean something else where PSA has 4 of those things, I do not have > a guess what you mean yet, hence my question above. > > Andy > > > On Mon, May 31, 2021 at 6:10 AM <verdi@ufscar.br> wrote: > >> Hello all, >> >> I tried to find this answer through the list but didn’t succeed to have a >> clear answer. >> >> The number of pipelines for PSA is 4. This is defined in the >> specification. However, I am wondering home many pipelines v1model has. I >> read somewhere here in the list that it is 2. That is correct? If yes, >> where such info is defined? >> >> Best, >> >> Fábio. >> _______________________________________________ >> P4-dev mailing list -- p4-dev@lists.p4.org >> To unsubscribe send an email to p4-dev-leave@lists.p4.org >> %(web_page_url)slistinfo%(cgiext)s/%(_internal_name)s > > -- Associate Prof. Fábio Luciano Verdi (UFSCar) Research Visitor at KTH - 2021-2022 http://www.dcomp.ufscar.br/verdi/
AF
Andy Fingerhut
Tue, Jun 1, 2021 1:19 PM

Some models of Tofino have 4 pipelines, although some models have only 2,
with corresponding reduction in total bandwidth of its ports.  You can see
a table of them in Section 12 of the now-public Tofino Native Architecture
specification here:
https://github.com/barefootnetworks/Open-Tofino/blob/master/PUBLIC_Tofino-Native-Arch-Document.pdf

The PSA specification mentions devices that might have multiple pipelines
in an appendix, because the PSA specification does not mandate that a
device have a particular number of pipelines.  e..g there could be a PSA
implementation with 1 pipeline, or 2, or any other number that a device
maker wants to build.  The main point of that appendix in the PSA
specification is to point out the consequences to a P4 programmer that
separate physical pipelines can have, e.g. meters and registers might be
implemented physically separately in each pipeline, and thus their state
only represents updates from packets processed by that pipeline, but not
updates of packets processed by other pipelines.

The v1model implemnetation in the BMv2 simple_switch / simple_switch_grpc
process only has 1 pipeline, in this sense.

The number of pipelines is not really mandated by v1modle or PSA.  It would
be possible to implement either of them with 1 pipeline, or more.  You'd
need to check with the device maker that implements the architecture how
many pipelines their device has.

Andy Fingerhut

On Tue, Jun 1, 2021 at 9:10 AM Fabio Luciano Verdi verdi@ufscar.br wrote:

Hi Andy,
I am talking about Section "E. Appendix: Multi-pipeline PSA devices" of
PSA Spec. However, I don't know from where I concluded that PSA has defined
4 pipelines. I think that is because I was reading (and working with) the
Tofino specs and that one has 4 pipelines.
And pipelines here are not meant to be ingress or egress, although it
seems that the same word is used for different contexts. Pipeline here
means the "physical" division of (physical) ports as is explained in the
Appendix E that I mentioned. Lets again use Tofino as our baseline. A
Tofino switch with 64 ports and 4 "pipelines" arranges 16 ports in each
"pipeline".
So, my question is how many of those "pipelines" v1 model has or supports.
Sorry for the confusion.
Best,
Fábio.

Em ter., 1 de jun. de 2021 às 14:56, Andy Fingerhut <
andy.fingerhut@gmail.com> escreveu:

You say "The number of pipelines for PSA is 4.  This is defined in the
specification."

Can you give a quote from the PSA specification, and what section number
the quote is from, that you got this from?

In particular, what do you mean when you say "pipeline"?  Do you mean
ingress is one pipeline, and egress is another pipeline?  In that sense of
the word "pipeline", both PSA and v1model have 2 pipelines.

If you mean something else where PSA has 4 of those things, I do not have
a guess what you mean yet, hence my question above.

Andy

On Mon, May 31, 2021 at 6:10 AM verdi@ufscar.br wrote:

Hello all,

I tried to find this answer through the list but didn’t succeed to have
a clear answer.

The number of pipelines for PSA is 4. This is defined in the
specification. However, I am wondering home many pipelines v1model has. I
read somewhere here in the list that it is 2. That is correct? If yes,
where such info is defined?

Best,

Fábio.


P4-dev mailing list -- p4-dev@lists.p4.org
To unsubscribe send an email to p4-dev-leave@lists.p4.org
%(web_page_url)slistinfo%(cgiext)s/%(_internal_name)s

--

Associate Prof. Fábio Luciano Verdi (UFSCar)

Research Visitor at KTH - 2021-2022

http://www.dcomp.ufscar.br/verdi/

Some models of Tofino have 4 pipelines, although some models have only 2, with corresponding reduction in total bandwidth of its ports. You can see a table of them in Section 12 of the now-public Tofino Native Architecture specification here: https://github.com/barefootnetworks/Open-Tofino/blob/master/PUBLIC_Tofino-Native-Arch-Document.pdf The PSA specification mentions devices that might have multiple pipelines in an appendix, because the PSA specification does not mandate that a device have a particular number of pipelines. e..g there could be a PSA implementation with 1 pipeline, or 2, or any other number that a device maker wants to build. The main point of that appendix in the PSA specification is to point out the consequences to a P4 programmer that separate physical pipelines can have, e.g. meters and registers might be implemented physically separately in each pipeline, and thus their state only represents updates from packets processed by that pipeline, but not updates of packets processed by other pipelines. The v1model implemnetation in the BMv2 simple_switch / simple_switch_grpc process only has 1 pipeline, in this sense. The number of pipelines is not really mandated by v1modle or PSA. It would be possible to implement either of them with 1 pipeline, or more. You'd need to check with the device maker that implements the architecture how many pipelines their device has. Andy Fingerhut On Tue, Jun 1, 2021 at 9:10 AM Fabio Luciano Verdi <verdi@ufscar.br> wrote: > Hi Andy, > I am talking about Section "E. Appendix: Multi-pipeline PSA devices" of > PSA Spec. However, I don't know from where I concluded that PSA has defined > 4 pipelines. I think that is because I was reading (and working with) the > Tofino specs and that one has 4 pipelines. > And pipelines here are not meant to be ingress or egress, although it > seems that the same word is used for different contexts. Pipeline here > means the "physical" division of (physical) ports as is explained in the > Appendix E that I mentioned. Lets again use Tofino as our baseline. A > Tofino switch with 64 ports and 4 "pipelines" arranges 16 ports in each > "pipeline". > So, my question is how many of those "pipelines" v1 model has or supports. > Sorry for the confusion. > Best, > Fábio. > > > > Em ter., 1 de jun. de 2021 às 14:56, Andy Fingerhut < > andy.fingerhut@gmail.com> escreveu: > >> You say "The number of pipelines for PSA is 4. This is defined in the >> specification." >> >> Can you give a quote from the PSA specification, and what section number >> the quote is from, that you got this from? >> >> In particular, what do you mean when you say "pipeline"? Do you mean >> ingress is one pipeline, and egress is another pipeline? In that sense of >> the word "pipeline", both PSA and v1model have 2 pipelines. >> >> If you mean something else where PSA has 4 of those things, I do not have >> a guess what you mean yet, hence my question above. >> >> Andy >> >> >> On Mon, May 31, 2021 at 6:10 AM <verdi@ufscar.br> wrote: >> >>> Hello all, >>> >>> I tried to find this answer through the list but didn’t succeed to have >>> a clear answer. >>> >>> The number of pipelines for PSA is 4. This is defined in the >>> specification. However, I am wondering home many pipelines v1model has. I >>> read somewhere here in the list that it is 2. That is correct? If yes, >>> where such info is defined? >>> >>> Best, >>> >>> Fábio. >>> _______________________________________________ >>> P4-dev mailing list -- p4-dev@lists.p4.org >>> To unsubscribe send an email to p4-dev-leave@lists.p4.org >>> %(web_page_url)slistinfo%(cgiext)s/%(_internal_name)s >> >> > > -- > > Associate Prof. Fábio Luciano Verdi (UFSCar) > > Research Visitor at KTH - 2021-2022 > > http://www.dcomp.ufscar.br/verdi/ >
FL
Fabio Luciano Verdi
Tue, Jun 1, 2021 1:31 PM

Yeah!
Thanks, Andy for the clarification.
best,
Fábio.

Em ter., 1 de jun. de 2021 às 15:19, Andy Fingerhut <
andy.fingerhut@gmail.com> escreveu:

Some models of Tofino have 4 pipelines, although some models have only 2,
with corresponding reduction in total bandwidth of its ports.  You can see
a table of them in Section 12 of the now-public Tofino Native Architecture
specification here:
https://github.com/barefootnetworks/Open-Tofino/blob/master/PUBLIC_Tofino-Native-Arch-Document.pdf

The PSA specification mentions devices that might have multiple pipelines
in an appendix, because the PSA specification does not mandate that a
device have a particular number of pipelines.  e..g there could be a PSA
implementation with 1 pipeline, or 2, or any other number that a device
maker wants to build.  The main point of that appendix in the PSA
specification is to point out the consequences to a P4 programmer that
separate physical pipelines can have, e.g. meters and registers might be
implemented physically separately in each pipeline, and thus their state
only represents updates from packets processed by that pipeline, but not
updates of packets processed by other pipelines.

The v1model implemnetation in the BMv2 simple_switch / simple_switch_grpc
process only has 1 pipeline, in this sense.

The number of pipelines is not really mandated by v1modle or PSA.  It
would be possible to implement either of them with 1 pipeline, or more.
You'd need to check with the device maker that implements the architecture
how many pipelines their device has.

Andy Fingerhut

On Tue, Jun 1, 2021 at 9:10 AM Fabio Luciano Verdi verdi@ufscar.br
wrote:

Hi Andy,
I am talking about Section "E. Appendix: Multi-pipeline PSA devices" of
PSA Spec. However, I don't know from where I concluded that PSA has defined
4 pipelines. I think that is because I was reading (and working with) the
Tofino specs and that one has 4 pipelines.
And pipelines here are not meant to be ingress or egress, although it
seems that the same word is used for different contexts. Pipeline here
means the "physical" division of (physical) ports as is explained in the
Appendix E that I mentioned. Lets again use Tofino as our baseline. A
Tofino switch with 64 ports and 4 "pipelines" arranges 16 ports in each
"pipeline".
So, my question is how many of those "pipelines" v1 model has or supports.
Sorry for the confusion.
Best,
Fábio.

Em ter., 1 de jun. de 2021 às 14:56, Andy Fingerhut <
andy.fingerhut@gmail.com> escreveu:

You say "The number of pipelines for PSA is 4.  This is defined in the
specification."

Can you give a quote from the PSA specification, and what section number
the quote is from, that you got this from?

In particular, what do you mean when you say "pipeline"?  Do you mean
ingress is one pipeline, and egress is another pipeline?  In that sense of
the word "pipeline", both PSA and v1model have 2 pipelines.

If you mean something else where PSA has 4 of those things, I do not
have a guess what you mean yet, hence my question above.

Andy

On Mon, May 31, 2021 at 6:10 AM verdi@ufscar.br wrote:

Hello all,

I tried to find this answer through the list but didn’t succeed to have
a clear answer.

The number of pipelines for PSA is 4. This is defined in the
specification. However, I am wondering home many pipelines v1model has. I
read somewhere here in the list that it is 2. That is correct? If yes,
where such info is defined?

Best,

Fábio.


P4-dev mailing list -- p4-dev@lists.p4.org
To unsubscribe send an email to p4-dev-leave@lists.p4.org
%(web_page_url)slistinfo%(cgiext)s/%(_internal_name)s

--

Associate Prof. Fábio Luciano Verdi (UFSCar)

Research Visitor at KTH - 2021-2022

http://www.dcomp.ufscar.br/verdi/

--

Associate Prof. Fábio Luciano Verdi (UFSCar)

Research Visitor at KTH - 2021-2022

http://www.dcomp.ufscar.br/verdi/

Yeah! Thanks, Andy for the clarification. best, Fábio. Em ter., 1 de jun. de 2021 às 15:19, Andy Fingerhut < andy.fingerhut@gmail.com> escreveu: > Some models of Tofino have 4 pipelines, although some models have only 2, > with corresponding reduction in total bandwidth of its ports. You can see > a table of them in Section 12 of the now-public Tofino Native Architecture > specification here: > https://github.com/barefootnetworks/Open-Tofino/blob/master/PUBLIC_Tofino-Native-Arch-Document.pdf > > The PSA specification mentions devices that might have multiple pipelines > in an appendix, because the PSA specification does not mandate that a > device have a particular number of pipelines. e..g there could be a PSA > implementation with 1 pipeline, or 2, or any other number that a device > maker wants to build. The main point of that appendix in the PSA > specification is to point out the consequences to a P4 programmer that > separate physical pipelines can have, e.g. meters and registers might be > implemented physically separately in each pipeline, and thus their state > only represents updates from packets processed by that pipeline, but not > updates of packets processed by other pipelines. > > The v1model implemnetation in the BMv2 simple_switch / simple_switch_grpc > process only has 1 pipeline, in this sense. > > The number of pipelines is not really mandated by v1modle or PSA. It > would be possible to implement either of them with 1 pipeline, or more. > You'd need to check with the device maker that implements the architecture > how many pipelines their device has. > > Andy Fingerhut > > > On Tue, Jun 1, 2021 at 9:10 AM Fabio Luciano Verdi <verdi@ufscar.br> > wrote: > >> Hi Andy, >> I am talking about Section "E. Appendix: Multi-pipeline PSA devices" of >> PSA Spec. However, I don't know from where I concluded that PSA has defined >> 4 pipelines. I think that is because I was reading (and working with) the >> Tofino specs and that one has 4 pipelines. >> And pipelines here are not meant to be ingress or egress, although it >> seems that the same word is used for different contexts. Pipeline here >> means the "physical" division of (physical) ports as is explained in the >> Appendix E that I mentioned. Lets again use Tofino as our baseline. A >> Tofino switch with 64 ports and 4 "pipelines" arranges 16 ports in each >> "pipeline". >> So, my question is how many of those "pipelines" v1 model has or supports. >> Sorry for the confusion. >> Best, >> Fábio. >> >> >> >> Em ter., 1 de jun. de 2021 às 14:56, Andy Fingerhut < >> andy.fingerhut@gmail.com> escreveu: >> >>> You say "The number of pipelines for PSA is 4. This is defined in the >>> specification." >>> >>> Can you give a quote from the PSA specification, and what section number >>> the quote is from, that you got this from? >>> >>> In particular, what do you mean when you say "pipeline"? Do you mean >>> ingress is one pipeline, and egress is another pipeline? In that sense of >>> the word "pipeline", both PSA and v1model have 2 pipelines. >>> >>> If you mean something else where PSA has 4 of those things, I do not >>> have a guess what you mean yet, hence my question above. >>> >>> Andy >>> >>> >>> On Mon, May 31, 2021 at 6:10 AM <verdi@ufscar.br> wrote: >>> >>>> Hello all, >>>> >>>> I tried to find this answer through the list but didn’t succeed to have >>>> a clear answer. >>>> >>>> The number of pipelines for PSA is 4. This is defined in the >>>> specification. However, I am wondering home many pipelines v1model has. I >>>> read somewhere here in the list that it is 2. That is correct? If yes, >>>> where such info is defined? >>>> >>>> Best, >>>> >>>> Fábio. >>>> _______________________________________________ >>>> P4-dev mailing list -- p4-dev@lists.p4.org >>>> To unsubscribe send an email to p4-dev-leave@lists.p4.org >>>> %(web_page_url)slistinfo%(cgiext)s/%(_internal_name)s >>> >>> >> >> -- >> >> Associate Prof. Fábio Luciano Verdi (UFSCar) >> >> Research Visitor at KTH - 2021-2022 >> >> http://www.dcomp.ufscar.br/verdi/ >> > -- Associate Prof. Fábio Luciano Verdi (UFSCar) Research Visitor at KTH - 2021-2022 http://www.dcomp.ufscar.br/verdi/