Re: [PATCH 3/4] rtla/timerlat: Add example for BPF action program

[Crystal Wood <crwood@redhat.com>]

On Tue, 2025-10-21 at 16:54 +0200, Tomas Glozar wrote:
> po 20. 10. 2025 v 19:53 odesílatel Crystal Wood <crwood@redhat.com> napsal:
> > 
> > We should have the makefile build this, and add a test that uses it.
> > 
> 
> I agree. I tried to use the example, but it would be also good to
> check if the BPF program was actually executed.
> 
> That is hard to do reliably for the current example, as it writes into
> the global tracefs instance, which might conflict with another user of
> the same instance. I will write another BPF program that will create a
> map instead, and a script that will check the map value via
> --on-threshold in the test.

Huh, so I guess BPF is an exception to the "no generic printk to the
global trace instance except for debugging that generates a big boot
splat" rule?

Speaking of which, why doesn't trace_osnoise.c call
trace_array_init_printk() given that it uses trace_array_printk_buf()?

-Crystal