Re: [PATCH v3 2/5] sched_ext: Manage the validity of scx_rq_clock
From: Tejun Heo
Date: Wed Dec 04 2024 - 13:46:41 EST
Hello,
On Wed, Dec 04, 2024 at 10:42:13AM +0900, Changwoo Min wrote:
> I investigated all sched_ext_ops. Besides these two ops, all the
> rest are control operations, of which BPF operation should be
> relatively simple. On the other hand, ops.running() and
> ops.update_idle() are different from the others since a CPU
> executes a task or becomes idle, which could be arbitrarily long.
> So I think refreshing the clock in those cases would be nice.
> Does it make sense to you?
Hmm... I'm not really following. Both ops.running() and ops.update_idle()
are called during task switches with rq lock held. I don't see why they'd be
any different in terms of expected runtime, which should be pretty short,
compared to any other rq-locked operations.
Thanks.
--
tejun