# \[PATCH 09/17\] sched/core: Add support for nohz\_full CPUs - From: Shrikanth Hegde \ - Date: 2025-11-19 12:46:03 - List: linuxppc-dev - Page: https://ratatoskr.run/linuxppc-dev/2025/11/3303744 - Thread: https://ratatoskr.run/linuxppc-dev/2025/11/3303735/t.md ```text Enable tick on nohz full CPU when it is marked as paravirt. If there in no CFS/RT running there, disable the tick to save the power. In addition to this, arch specific code which enables the paravirt CPU should call, tick_nohz_dep_set_cpu with TICK_DEP_BIT_SCHED for moving the task out of nohz_full CPU fast. Signed-off-by: Shrikanth Hegde --- kernel/sched/core.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 90fc04d84b74..73d1d49a3c72 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1336,6 +1336,10 @@ bool sched_can_stop_tick(struct rq *rq) { int fifo_nr_running; + /* Keep the tick running until both RT and CFS are pushed out*/ + if (cpu_paravirt(rq->cpu) && (rq->rt.rt_nr_running || rq->cfs.h_nr_queued)) + return false; + /* Deadline tasks, even if single, need the tick */ if (rq->dl.dl_nr_running) return false; -- 2.47.3 ```