Re: [PATCH] sched/fair: Prevent cfs_rq from being unthrottled with zero runtime_remaining

[Aaron Lu]

On Tue, Sep 30, 2025 at 07:08:20PM +0530, K Prateek Nayak wrote:
> Hello Aaron,
> 
> I'll merge the two replies in one.
> 
> On 9/30/2025 4:37 PM, Aaron Lu wrote:
> > So in my original patch, cfs_rqs will (most likely) start with
> > runtime_remaining == 1 and unthrottled after calling throttle_cfs_rq(),
> > which will also start the B/W timer. The timer is not needed in this
> > case when no cfs_rqs are actually throttled but it doesn't hurt. Looks
> > like everything is OK, we do not need to do any special handling in
> > enqueue_throttled_task(). Thoughts?
> 
> Now that I look at throttle_cfs_rq() properly, we'll only move the
> runtime_remaining from 0 to 1 so few usecs worth of bandwidth
> distributed at max should be okay. Sorry for the being overly cautious!

Never mind.

> 
> So your current approach should be good. Please feel free to include:
> 
> Reviewed-by: K Prateek Nayak <kprateek.nayak@xxxxxxx>

Thanks!