Re: [dpdk-dev] Question about telemetry on 18.11 release

[Rami Rosen <roszenrami@gmail.com>]

Hi Hideyuki,

Regarding your questions about DPDK CPU usage, etc:
I believe that due to the way PMDs are implemented, maybe one
should consider using DPDK RTE jobstats API for collecting stats for a DPDK
app. This API reflects better the actual DPDK app stats.
See an example in:
https://doc.dpdk.org/guides/sample_app_ug/l2_forward_job_stats.html
And also see:
https://doc.dpdk.org/api/rte__jobstats_8h_source.html

Regards,
Rami Rosen

בתאריך יום ד׳, 21 בנוב׳ 2018, 09:50, מאת Hideyuki Yamashita <
yamashita.hideyuki@po.ntt-tx.co.jp>:

> Hello,
>
> I have some basic questions about telemetry API
> which is planned to be relaesed in 18.11.
>
> Note that I have read the follwoing document.
> https://doc.dpdk.org/guides/howto/telemetry.html
>
> Q1. In general dpdk application use polling when
> receiving packets. So CPU usage is always looks 100%
> when measured using e.g. vmstat even if there is no packet receiving.
> (CPU is busy for polling packets)
> Is that correct?
>
> Q2. Is it correct understanding that dpdk application
> can send "any" value(or metric) to client if client
> requested via "telemetry" framework?
>
> Q3.Is it possible to query "real cpu usage" from dpdk
> application using "telemetry" framework?
> ("real cpu usage" I mean if 0 pakcket incoming,
> cpu usage indicates almost 0 %)
>
> Q4. Is it possible to inform client about fault or some
> trouble from dpdk application?
>
> Background  I ask above is that
> - I am relative new to DPDK world and have almost no knowledge about
> "telemetry"
> - I am interested in how dpdk applications can "scales" on platform
> like OpenStack. I think some mesurement mechanism required
> and I thought it might be "telemetry" APIs.
>
> Thanks in advance.
>
> BR,
> Hideyuki Yamashita
> NTT TechnoCross
>
>
>