[PATCH 04/17] sched_ext: Shift scx_kick_cpu() validity check to scx_bpf_kick_cpu()

Tejun Heo
2026-04-28T20:35:51Z

Callers that already know the cpu is valid shouldn't have to pay for a
redundant check. scx_kick_cpu() is called from the in-kernel balance loop
break-out path with the current cpu (trivially valid) and from
scx_bpf_kick_cpu() with a BPF-supplied cpu that does need validation. Move
the check out of scx_kick_cpu() into scx_bpf_kick_cpu() so the backend is
reusable by callers that have already validated.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Cheng-Yang Chou <yphbchou0911@gmail.com>
---
kernel/sched/ext.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index 8d41b4e2cce6..e9cf9d8f4626 100644
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -8786,9 +8786,6 @@ static void scx_kick_cpu(struct scx_sched *sch, s32 cpu, u64 flags)
struct rq *this_rq;
unsigned long irq_flags;

- if (!scx_cpu_valid(sch, cpu, NULL))
- return;
-
local_irq_save(irq_flags);

this_rq = this_rq();
@@ -8851,7 +8848,7 @@ __bpf_kfunc void scx_bpf_kick_cpu(s32 cpu, u64 flags, const struct bpf_prog_aux

guard(rcu)();
sch = scx_prog_sched(aux);
- if (likely(sch))
+ if (likely(sch) && scx_cpu_valid(sch, cpu, NULL))
scx_kick_cpu(sch, cpu, flags);
}

--
2.54.0