Re: [PATCH 10/12] sched: Add locking comments to sched_class methods

[Juri Lelli]

On 08/10/25 09:33, Greg Kroah-Hartman wrote:
> On Wed, Oct 08, 2025 at 09:04:19AM +0200, Peter Zijlstra wrote:
> > On Tue, Oct 07, 2025 at 11:54:18AM +0200, Juri Lelli wrote:
> > 
> > > Not for this patch, but I wondered if, while we are at it, we wanted to
> > > complete documentation of these flags. My new AI friend is suggesting
> > > the following, is it very much garbage? :)
> > 
> > Heh; its not terrible. I've been playing with local LLMs, but mostly
> > I've found they struggle with getting enough context to not be utterly
> > demented. And when you up the context window, they get unusable slow :/
> > 
> > Setting up and configuring the whole pile of subtly interlocking stacks
> > of software to get anything useful out of this stuff is non-trivial (it
> > reminds me of the sendmail m4 days).
> > 
> > > ---
> > > 
> > > From: Claude <claude-sonnet-4-5@xxxxxxxxxxxxx>
> > > Date: Mon, 7 Oct 2025 12:44:13 +0200
> > > Subject: sched: Document remaining DEQUEUE/ENQUEUE flags
> > > 
> > > Complete the flag documentation by adding descriptions for the three
> > > previously undocumented flags: DEQUEUE_SPECIAL, DEQUEUE_THROTTLE, and
> > > ENQUEUE_INITIAL.
> > > 
> > > DEQUEUE_SPECIAL is used when dequeuing tasks in special states (stopped,
> > > traced, parked, dead, or frozen) that don't use the normal wait-loop
> > > pattern and must not use delayed dequeue.
> > > 
> > > DEQUEUE_THROTTLE is used when removing tasks from the runqueue due to
> > > CFS bandwidth throttling, preventing delayed dequeue to ensure proper
> > > throttling behavior.
> > > 
> > > ENQUEUE_INITIAL is used when enqueueing newly created tasks in
> > > wake_up_new_task(), allowing the fair scheduler to give them preferential
> > > initial placement (half vslice when PLACE_DEADLINE_INITIAL is enabled).
> > > 
> > > Signed-off-by: Claude <claude-sonnet-4-5@xxxxxxxxxxxxx>
> > > Not-so-sure-yet: Juri Lelli <juri.lelli@xxxxxxxxxx>
> > 
> > Is this the generally acceptable form of attribution for these things?
> > I'm not sure what the official guidance is on using these AI tools.
> > 
> > Greg, you have any insights here?
> 
> First off, Claude can NOT sign off on anything, so that's a non-starter.
> All Red Hat people should know that :)

Yep, knew that. But I felt guilty nontheless as I didn't touch the
change at all. Current SoB was kind of a (silly) joke. :)

> Otherwise, there is a draft of something that was going to address stuff
> like this floating around by Dave Hansen, I'll go poke him to see what
> the status of that is.

I believe it was suggested something like Co-developed-by: <model> and
then Signed-off-by: <human>, but indeed curious to know how that
discussion ended.

Thanks!
Juri