[PATCH sched_ext/for-6.19] sched_ext: Mark racy bitfields to prevent adding fields that can't tolerate races

[Tejun Heo <tj@kernel.org>]

The warned bitfields in struct scx_sched are updated racily from concurrent
CPUs causing RMW races, which is fine for these boolean warning flags. Add a
comment marking this area to prevent future fields that can't tolerate racy
updates from being added here.

Signed-off-by: Tejun Heo <tj@kernel.org>
---
 kernel/sched/ext_internal.h |    4 ++++
 1 file changed, 4 insertions(+)

--- a/kernel/sched/ext_internal.h
+++ b/kernel/sched/ext_internal.h
@@ -895,6 +895,10 @@ struct scx_sched {
 	struct scx_dispatch_q	**global_dsqs;
 	struct scx_sched_pcpu __percpu *pcpu;

+	/*
+	 * Updates to the following warned bitfields can race causing RMW issues
+	 * but it doesn't really matter.
+	 */
 	bool			warned_zero_slice:1;
 	bool			warned_deprecated_rq:1;