Re: [PATCH] sched_ext: Provide a sysfs enable_seq counter

[Phil Auld <pauld@redhat.com>]

Hi Tejun,

On Sun, Sep 22, 2024 at 11:21:02AM -1000 Tejun Heo wrote:
> Hello, Andrea.
> 
> On Sat, Sep 21, 2024 at 09:39:21PM +0200, andrea.righi@linux.dev wrote:
> >  static struct attribute *scx_global_attrs[] = {
> >  	&scx_attr_state.attr,
> >  	&scx_attr_switch_all.attr,
> >  	&scx_attr_nr_rejected.attr,
> >  	&scx_attr_hotplug_seq.attr,
> > +	&scx_attr_enable_seq.attr,
> >  	NULL,
> >  };
> 
> Can you put this in scx_sched_attrs instead as it probably would make sense
> to track this per-scheduler in the future when we support stacked
> schedulers.

It's not a per scheduler counter, though. It's global. We want to know
that a (any) scx scheduler has been loaded at some time in the past. It's
really only interesting when 0 or > 0. The actual non-zero number and which
scheduler(s) don't matter that much.

And it needs to persist when the scheduler is unloaded (I didn't look but
I uspect the per scheduler attrs come and go?).


Cheers,
Phil

> 
> Thanks.
> 
> -- 
> tejun
> 

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