Re: SCHED_DEADLINE as user

[Juri Lelli <juri.lelli@gmail.com>]

On 21/08/18 09:38, Juri Lelli wrote:
> On 21/08/18 00:45, Tim Blechmann wrote:
> 
> [...]
> 
> > apart from that, i'm only missing two features:
> > 
> > * using SCHED_DEADLINE from user applications is kind of a showstopper
> > for me
> 
> Right. Would you be up for continuing experimenting with DEADLINE (while
> we get our heads around removing this constraint) by - ugly hack warning
> - removing the check at
> 
> https://elixir.bootlin.com/linux/latest/source/kernel/sched/core.c#L4216
> 
> ?
> 
> I guess it would be good if you could provide even more feedback than
> you already did, so that we can plan ahead what needs fixing/changing or
> implementing.
> 
> BTW, thanks a lot already for this discussion! :-)
> 
> > * a nicer glibc wrapper, that allows me to use pthreads rather than
> > using `syscall`: it's all pretty easy to obtain the `tid` for a calling
> > thread (gettid), but it seems to be impossible to obtain the `tid` from
> >  `pthread_t` without some hacks which are way too dirty to share in
> > public ...
> 
> Indeed. We have been basically relying on
> 
> https://github.com/scheduler-tools/rt-app/tree/master/libdl
> 
> so far. But, I guess it's time - it has been time for a while - that we
> reach glibc guys and try to understand why this is not yet all in the
> standard libraries.

FYI, I added both points to the list of known issues. Feel free to add
details.

https://github.com/jlelli/linux/issues

Best,

- Juri