Re: [RFC 0/1][PATCH] POSIX SCHED_SPORADIC implementation for tasks and groups

[Ulrich Drepper <drepper@redhat.com>]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Dario Faggioli wrote:
> I'm spending some time implementing the POSIX real-time SCHED_SPORADIC
> scheduling policy on top of the mainline Linux kernel, and here it is
> the code in its very first version.

I'm not commenting on the code or usefulness of ht features.  I just
want to point out a problem.

The authors of that POSIX extension unfortunately decided to extend the
sched_param structure.  If you look at the definition of that structure
Linux uses you'll see that there is no place for this.  I.e., any
implementation of that feature following the POSIX spec to the letter
will introduce major headache in the form of binary incompatibility.

In case the features is useful enough (I actually always thought it
isn't an have actually proposed to remove it again from POSIX) then I
would rather prefer to not claim support for this feature in the POSIX
way.  One could still implement it as described.  But change the
interface to not require the sched_param change.

- --
➧ Ulrich Drepper ➧ Red Hat, Inc. ➧ 444 Castro St ➧ Mountain View, CA ❖
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.9 (GNU/Linux)

iEYEARECAAYFAkigSHsACgkQ2ijCOnn/RHS23QCfWNJRqnrhgSXGpnNag/nVeKcC
uwIAn3fUIwku+i+xegBDhfh5yaIW/VCo
=LCa/
-----END PGP SIGNATURE-----