Re: [PATCH v3 1/3] eal: add lcore poll busyness telemetry

[Bruce Richardson <bruce.richardson@intel.com>]

On Sat, Aug 27, 2022 at 12:06:19AM +0200, Mattias Rönnblom wrote:
> On 2022-08-25 17:28, Kevin Laatz wrote:
> > From: Anatoly Burakov <anatoly.burakov@intel.com>
> > 
<snip>
> > This patch also adds a telemetry endpoint to report lcore poll busyness, as
> > well as telemetry endpoints to enable/disable lcore telemetry. A
> > documentation entry has been added to the howto guides to explain the usage
> > of the new telemetry endpoints and API.
> > 
> 
> Should there really be a dependency from the EAL to the telemetry library? A
> cycle. Maybe some dependency inversion would be in order? The telemetry
> library could instead register an interest in getting busy/idle cycles
> reports from lcores.
> 
Just on this point, EAL already exposes telemetry and already depends upon
the telemetry library, so there would be no new dependency introduced here.

With the existing code, we avoid a cycle by having telemetry avoid using
EAL functions - and for the couple it does need, e.g. the log function, we
inject in the function pointer on init.

/Bruce