Re: [RESEND][PATCH v21 0/6] Donor Migration for Proxy Execution (v21)

[Juri Lelli <juri.lelli@redhat.com>]

Hi John,

On 04/09/25 00:21, John Stultz wrote:
> Hey All,
> 
> I didn't get any feedback on the last iteration, so I wanted to
> resend this next chunk of the series: Donor Migration 

Not ignoring you, but I had to spend some time putting together some
testing infra I am not trying to use to see how DEADLINE behaves with
the series, as it's somewhat difficult for me to think in abstract about
all this. :)

> Also you can find the full proxy-exec series here:
>   https://github.com/johnstultz-work/linux-dev/commits/proxy-exec-v21-6.17-rc4/
>   https://github.com/johnstultz-work/linux-dev.git proxy-exec-v21-6.17-rc4
> 

> I’d really appreciate any feedback or review thoughts on the
> full series as well.

I current have the following on top of your complete series

https://github.com/jlelli/linux/commits/experimental/eval-mbwi/
https://github.com/jlelli/linux experimental/eval-mbwi

of which

https://github.com/jlelli/linux/commit/9d4bbb1aca624e76e5b34938d848dc9a418c6146

introduces the testing (M-BWI is Multiprocessor Bandwidth Inheritance)
infra and the rest some additional tracepoints (based on Gabriele's
patch) to get more DEADLINE info out of tests (in conjuction with
sched_tp [1]).

Nothing bit to report just yet, mainly spent time getting this working.

One thing I noticed thouh (and probably forgot from previous
discussions) is that spin_on_owner might be 'confusing' from an
RT/DEADLINE perspective as it deviates from what one expects from the
ideal theoretical world (as tasks don't immediately block and
potentially donate). Not sure what to do about it. Maybe special case it
for RT/DEADLINE, but just started playing with it.

Anyway, I will keep playing with all this. Just wanted to give
you/others a quick update. Also adding Luca, Tommaso and Yuri to the
thread so that they are aware of the testing framework. :)

Thanks!
Juri

1 - https://github.com/jlelli/sched_tp/tree/deadline-tp
    will open an MR against Qais' mainline repo as soon as TPs are
    hopefully merged upstream as well.