Re: [PATCH 01/13] sched: Add 3 new scheduler syscalls to support anextended scheduling parameters ABI

From: Peter Zijlstra
Date: Tue Jan 21 2014 - 10:46:40 EST

On Tue, Jan 21, 2014 at 04:38:51PM +0100, Peter Zijlstra wrote:
> SCHED_DEADLINE: Sporadic task model deadline scheduling
> SCHED_DEADLINE is an implementation of GEDF (Global Earliest
> Deadline First) with additional CBS (Constant Bandwidth Server).

We might want to re-word that to:

SCHED_DEADLINE currently is an implementation of GEDF, however
any policy that correctly schedules the sporadic task model is
a valid implementation.

To make sure we should not rely on the actual implementation; there's
many possible algorithms to schedule the sporadic task model.

> The CBS guarantees that tasks that over-run their specified
> budget are throttled and do not affect the correct performance
> of other SCHED_DEADLINE tasks.
> SCHED_DEADLINE tasks will fail FORK(2) with -EAGAIN
> Setting SCHED_DEADLINE can fail with -EINVAL when admission
> control tests fail.
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at