Re: [dpdk-dev] Retrieving lcore worker thread id

["Van Haaren, Harry" <harry.van.haaren@intel.com>]

> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Mattias Rönnblom
> Sent: Tuesday, July 14, 2020 1:04 PM
> To: dpdk-dev <dev@dpdk.org>
> Cc: Tomasz Piatkowski <tomasz.piatkowski@ericsson.com>
> Subject: [dpdk-dev] Retrieving lcore worker thread id
> 
> Hi.

Hey,

> In DPDK 19.11, the lcore_config struct of <rte_lcore.h> is made private,
> and with it the possibility to look up the thread id of the lcore worker
> threads disappears.
> 
> One use case is an application with a monitoring function (on some
> control plane thread), which uses the thread ids to make sure the worker
> threads gets the CPU runtime they should, and thus is able to detect
> stalls.
> 
> Is there some other way of finding out the thread_id of a lcore worker
> thread? All I can think of are hacks like using a temporary service
> function for service cores, in combination with requiring launched
> application threads also to store their thread id in some global
> structure (index by lcore_id).

-1 for the service cores idea. I like the creative solution thinking,
but not as a long-term solution.

> Is there some cleaner way? If not, would adding something like a
> rte_lcore_thread_id() function make sense?

I think given your use-case description above, this makes sense.
I guess it comes down to a discussion around if thread_id should
be exposed at all - but given you have a use I'd argue yes it should.
Doing so in a cross-platform way might be a bit tricky though.

> Regards,
>      Mattias

Regards, -Harry