Re: [PATCH 2/5] sched/fair: Use throttled_csd_list for local unthrottle

From: Benjamin Segall

Date: Thu May 28 2026 - 17:53:55 EST


K Prateek Nayak <kprateek.nayak@xxxxxxx> writes:

> When distribute_cfs_runtime() encounters a local cfs_rq, it adds it to a
> local list and unthrottles it at the end, when it is done unthrottling
> other cfs_rq(s) on cfs_b->throttled_cfs_rq until the bandwidth runs out.
>
> Instead of using a local list, reuse the local CPU's
> rq->throttled_csd_list and the __cfsb_csd_unthrottle() path for
> unthrottle.
>
> If this is the first cfs_rq to be queued on the "throttled_csd_list", it
> prevents the need for a remote CPUs to interrupt this local CPU if they
> themselves are performing async unthrottle.
>
> If this is not the first cfs_rq on the list, there is an async unthrottle
> operation pending on this local CPU and the unthrottle can be batched
> together.
>
> No functional changes intended.

Reviewed-By: Benjamin Segall <bsegall@xxxxxxxxxx>