Re: [PATCH v4 1/9] sched: Add a generic function to return the preemption string.

[Ingo Molnar]

* Ingo Molnar <mingo@xxxxxxxxxx> wrote:

> 
> * Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> wrote:
> 
> > On 2025-03-17 10:12:31 [+0100], Ingo Molnar wrote:
> > > 
> > > * Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> wrote:
> > > 
> > > > On 2025-03-16 12:15:47 [+0100], Ingo Molnar wrote:
> > > > > 
> > > > > * Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> wrote:
> > > > > 
> > > > > > +const char *preempt_modes[] = {
> > > > > > +	"none", "voluntary", "full", "lazy", NULL,
> > > > > > +};
> > > > > 
> > > > > > +	/* Count entries in NULL terminated preempt_modes */
> > > > > > +	for (j = 0; preempt_modes[j]; j++)
> > > > > > +		;
> > > > > 
> > > > > I'm pretty sure the build-time ARRAY_SIZE() primitive is superior here. ;-)
> > > > 
> > > > It would be but it is not an option.
> > > > That array is defined in core.c where it is "always" required while
> > > > debug.c needs it optionally. core.c is its one compile unit while
> > > > debug.c is included by build_utility.c. So I don't see how this can work
> > > > unless we shift things:
> > > 
> > > Why not have it all in debug.c?
> > 
> > The debug.c include is behind CONFIG_SCHED_DEBUG. This needs to be moved
> > into debug.c itself so that code can be added regardless of
> > CONFIG_SCHED_DEBUG. It is not only sched-debug after that.
> 
> Yeah, that's a valid concern.
> 
> The thing is, CONFIG_SCHED_DEBUG is mostly meaningless these days - all 
> major distributions enable it because of the statistics are useful for 
> system administration, tooling and general software development.
> 
> So we should enable it permanently and remove the #ifdeffery. I'll send 
> out a series to do so soon.

Here's the series:

  https://lore.kernel.org/r/20250317104257.3496611-1-mingo@xxxxxxxxxx

  Ingo Molnar (5):
      sched/debug: Change SCHED_WARN_ON() to WARN_ON_ONCE()
      sched/debug: Make 'const_debug' tunables unconditional __read_mostly
      sched/debug: Make CONFIG_SCHED_DEBUG functionality unconditional
      sched/debug, Documentation: Remove (most) CONFIG_SCHED_DEBUG references from documentation
      sched/debug: Remove CONFIG_SCHED_DEBUG

Forgot to Cc: you - will do so in future versions.

Thanks,

	Ingo