sched_ext: deprecation warn for scx_bpf_cpu_rq()

scx_bpf_cpu_rq() works on an unlocked rq which generally isn't safe.
For the common use-cases scx_bpf_locked_rq() and
scx_bpf_cpu_curr() work, so add a deprecation warning
to scx_bpf_cpu_rq() so it can eventually be removed.

Signed-off-by: Christian Loehle <christian.loehle@arm.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/kernel/sched/ext_internal.h b/kernel/sched/ext_internal.h
index af4c054fb6f8..2e289931e567 100644
--- a/kernel/sched/ext_internal.h
+++ b/kernel/sched/ext_internal.h
@@ -872,6 +872,7 @@ struct scx_sched {
 	struct scx_sched_pcpu __percpu *pcpu;
 
 	bool			warned_zero_slice;
+	bool			warned_deprecated_rq;
 
 	atomic_t		exit_kind;
 	struct scx_exit_info	*exit_info;