Re: DPDK and energy efficiency

[Etienne-Victor Depasquale <edepa () ieee org>]

Sorry, last line should have been:
"intended to get an impression of how widespread ***knowledge of*** DPDK's
core operating inefficiency is",
not:
"intended to get an impression of how widespread DPDK's core operating
inefficiency is"

On Tue, Feb 23, 2021 at 8:22 AM Etienne-Victor Depasquale <edepa () ieee org>
wrote:

> Beyond RX/TX CPU affinity, in DANOS you can further tune power consumption
> > by changing the adaptive polling rate.  It doesn’t, per the survey, "keep
> > utilization at 100% regardless of packet activity.”
> Robert, you seem to be conflating DPDK
> with DANOS' power control algorithms that modulate DPDK's default
> behaviour.
>
> Let me know what you think; otherwise, I'm pretty confident that DPDK does:
>
> > "keep utilization at 100% regardless of packet activity.”
>
>
> Keep in mind that this is a bare-bones survey intended for busy,
> knowledgeable people (the ones you'd find on NANOG) -
> not a detailed breakdown of modes of operation of DPDK or DANOS.
> DPDK has been designed for fast I/O that's unencumbered by the trappings
> of general-purpose OSes,
> and that's the impression that needs to be forefront.
> Power control, as well as any other dimensions of modulation,
> are detailed modes of operation that are well beyond the scope of a
> bare-bones 2-question survey
> intended to get an impression of how widespread DPDK's core operating
> inefficiency is.
>
> Cheers,
>
> Etienne
>
> On Mon, Feb 22, 2021 at 10:20 PM Robert Bays <robert () gdk org> wrote:
>
> > Beyond RX/TX CPU affinity, in DANOS you can further tune power
> > consumption by changing the adaptive polling rate.  It doesn’t, per the
> > survey, "keep utilization at 100% regardless of packet activity.”  Adaptive
> > polling changes in DPDK optimize for tradeoffs between power consumption,
> > latency/jitter and drops during throughput ramp up periods.  Ideally your
> > DPDK implementation has an algorithm that tries to automatically optimize
> > based on current traffic patterns.
> >
> > In DANOS refer to the “system default dataplane power-profile” config
> > command tree for adaptive polling settings.  Interface RX/TX affinity is
> > configured on a per interface basis under the “interfaces dataplane” config
> > command tree.
> >
> > -robert
> >
> >
> > > On Feb 22, 2021, at 11:46 AM, Jared Geiger <jared () compuwizz net> wrote:
> > >
> > > DANOS lets you specify how many dataplane cores you use versus control
> > plane cores. So if you put a 16 core host in to handle 2GB of traffic, you
> > can adjust the dataplane worker cores as needed. Control plane cores don't
> > stay at 100% utilization.
> > > I use that technique plus DANOS runs on VMware (not oversubscribed)
> > which allows me to use the hardware for other VMs. NICS are attached to the
> > VM via PCI Passthrough which helps eliminate the overhead to the VMware
> > hypervisor itself.
> > > I have an 8 core VM with 4 cores set to dataplane and 4 to control
> > plane. The 4 control plane cores are typically idle only processing BGP
> > route updates, SNMP, logs, etc.
> > > ~Jared
> > >
> > > On Sun, Feb 21, 2021 at 11:30 PM Etienne-Victor Depasquale <
> > edepa () ieee org> wrote:
> > > Hello folks,
> > >
> > > I've just followed a thread regarding use of CGNAT and noted a
> > suggestion (regarding DANOS) that includes use of DPDK.
> > > As I'm interested in the breadth of adoption of DPDK, and as I'm a
> > researcher into energy and power efficiency, I'd love to hear your feedback
> > on your use of power consumption control by DPDK.
> > > I've drawn up a bare-bones, 2-question survey at this link:
> > >
> > > https://www.surveymonkey.com/r/J886DPY.
> > >
> > > Responses have been set to anonymous.
> > >
> > > Cheers,
> > >
> > > Etienne
> > >
> > > --
> > > Ing. Etienne-Victor Depasquale
> > > Assistant Lecturer
> > > Department of Communications & Computer Engineering
> > > Faculty of Information & Communication Technology
> > > University of Malta
> > > Web. https://www.um.edu.mt/profile/etiennedepasquale
>
> --
> Ing. Etienne-Victor Depasquale
> Assistant Lecturer
> Department of Communications & Computer Engineering
> Faculty of Information & Communication Technology
> University of Malta
> Web. https://www.um.edu.mt/profile/etiennedepasquale


-- 
Ing. Etienne-Victor Depasquale
Assistant Lecturer
Department of Communications & Computer Engineering
Faculty of Information & Communication Technology
University of Malta
Web. https://www.um.edu.mt/profile/etiennedepasquale