diff options
Diffstat (limited to 'kernel/sched.c')
| -rw-r--r-- | kernel/sched.c | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index 1ca987256375..590b9bb06540 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -6653,7 +6653,25 @@ recheck: if (running) p->sched_class->set_curr_task(rq); if (on_rq) { - activate_task(rq, p, 0, false); + /* + * Workaround to make prio ceiling work as expected: + * + * Queue task to head when task is running and task is + * lowering its priority. This works around the non- + * availability of a sched_setprio syscall which was + * tinkered into the posix spec to make prio ceiling + * work correctly. + * + * This workaround violates the posix scheduling + * semantics of tail queueing in the case that the + * priority was changed by anything else than + * sched_setprio, but there is no other breakage + * lurking than some specification fetishists going + * berserk on me. + * + * Fixing this in mainline needs more thoughts. + */ + activate_task(rq, p, 0, running && oldprio < p->prio); check_class_changed(rq, p, prev_class, oldprio, running); } |