Re: [PATCH v2 2/3] sched/fair: Make cfs_rq::idle the sum of ancestor tg::idle

[Josh Don]

On Sat, Nov 7, 2026 at 3:36 AM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>
>
> Rather than keeping cfs_rq::idle as a copy of tg::idle, make it the sum of
> all ancestor tg::idle. This makes it trivial to tell if the current cgroup
> is marked idle somewhere along its ancestral path.
>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
> ---
>  kernel/sched/debug.c |    1
>  kernel/sched/fair.c  |   88 +++++++++++++++++++++++++++++++--------------------
>  kernel/sched/sched.h |    2 -
>  3 files changed, 56 insertions(+), 35 deletions(-)

I think this needs better handling now in the next patch in this
chain, but this one looks good. I'll move that discussion over to
patch 3.

Reviewed-by: Josh Don <joshdon@xxxxxxxxxx>