[Xenomai-core] Policy switching and XNOTHER maintenance

[Jan Kiszka <jan.kiszka@domain.hid>]

[-- Attachment #1: Type: text/plain, Size: 771 bytes --]

Hi all,

just looked into the hrescnt issue again, specifically the corner case
of a shadow thread switching from real-time policy to SCHED_OTHER.

Looks like we don't support this at all ATM:

do_setsched_event ignores events that enabled SCHED_OTHER, and the
XNOTHER flag is only set on xnshadow_map, not updated anywhere else.
Fixing this is not straightforward as that flag resides in a state
variable that is owned by the thread (ie. updated non-atomically) while
do_setsched_event can also be called over different contexts.

Or am I missing something?

In the light of this, I would vote for reverting f9bfab3457 ("only
update rescnt for XNOTHER threads") as it only adds conditional branches
to the hot paths without solving the issue.

Jan


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 262 bytes --]