Re: [PATCH 0/2] sched_ext: Add a core event and update scx schedulers

[Changwoo Min]

Hi Tejun and Andrea,

On 25. 2. 8. 06:45, Andrea Righi wrote:
> On Fri, Feb 07, 2025 at 11:38:31AM -1000, Tejun Heo wrote:
> > I'm not sure. BPF schedulers should be able to avoid getting the default
> > slice. Hopefully, with the added visibility, this should be easier now. I'm
> > not sure how much overriding the default value in ops helps in terms of
> > control. It's a very half-way measure. Instead, how about we add tracepoint
> > to scx_add_event() so that folks who want to get backtrace of specific
> > events can get them easily so that it's easier to debug where these counts
> > are coming from? Let's just make it easier to avoid these events.
>
> Yeah, that's a valid point, the implicit SCX_SLICE_DFL should be seen as a
> countermeasure for unhandled situations. Instead of fixing the
> countermeasure itself we should try to prevent it, if it proves to be
> problematic. And I like the idea of having a way to backtrace specific
> events.

I agree that adding a tracepoint to scx_add_event() and 
__scx_add_event() is a defenitely useful extension to further 
investigate what's going on. I will take a look.

Regards,
Changwoo Min