Re: [PATCH] sched/fair: vruntime should normalize when switching from fair

[Dietmar Eggemann]

On 09/07/2018 12:58 AM, Vincent Guittot wrote:
> On Fri, 7 Sep 2018 at 09:16, Juri Lelli <juri.lelli@xxxxxxxxx> wrote:
> > On 06/09/18 16:25, Dietmar Eggemann wrote:
> > > Hi Juri,
> > >
> > > On 08/23/2018 11:54 PM, Juri Lelli wrote:
> > > > On 23/08/18 18:52, Dietmar Eggemann wrote:
> > > > > Hi,
> > > > >
> > > > > On 08/21/2018 01:54 AM, Miguel de Dios wrote:
> > > > > > On 08/17/2018 11:27 AM, Steve Muckle wrote:
> > > > > > > From: John Dias <joaodias@xxxxxxxxxx>

[...]

> > > Adding semaphores is possible but rt-app has no easy way to initialize
> > > individual objects, e.g. sem_init(..., value). The only way I see is via the
> > > global section, like "pi_enabled". But then, this is true for all objects of
> > > this kind (in this case mutexes)?
> >
> > Right, global section should work fine. Why do you think this is a
> > problem/limitation?
>
> keep in mind that rt-app still have "ressources" section. This one is
> optional and almost never used as resources can be created on the fly
> but it's still there and can be used to initialize resources if needed
> like semaphore

I wasn't aware of that but this will do the job AFAICS. I just have to 
re-introduce the direct calls to init_foo_resource() (in this case 
init_sem_resource()) in init_resource_data() and call that instead of 
init_resource_data() for semaphores listed in the global resources section.

Example for a semaphore b_sem with initial value eq. 1:

    "resources" : {
        "b_sem" : { "type" : "sem_wait", "value" : 1 }
    }

[...]