From cfe43f478b79ba45573ca22d52d0d8823be068fa Mon Sep 17 00:00:00 2001 From: Valentin Schneider Date: Fri, 12 Nov 2021 18:52:01 +0000 Subject: preempt/dynamic: Introduce preemption model accessors CONFIG_PREEMPT{_NONE, _VOLUNTARY} designate either: o The build-time preemption model when !PREEMPT_DYNAMIC o The default boot-time preemption model when PREEMPT_DYNAMIC IOW, using those on PREEMPT_DYNAMIC kernels is meaningless - the actual model could have been set to something else by the "preempt=foo" cmdline parameter. Same problem applies to CONFIG_PREEMPTION. Introduce a set of helpers to determine the actual preemption model used by the live kernel. Suggested-by: Marco Elver Signed-off-by: Valentin Schneider Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Marco Elver Acked-by: Frederic Weisbecker Link: https://lore.kernel.org/r/20211112185203.280040-3-valentin.schneider@arm.com --- kernel/sched/core.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'kernel/sched') diff --git a/kernel/sched/core.c b/kernel/sched/core.c index d575b4914925..068c088e9584 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -8409,6 +8409,18 @@ static void __init preempt_dynamic_init(void) } } +#define PREEMPT_MODEL_ACCESSOR(mode) \ + bool preempt_model_##mode(void) \ + { \ + WARN_ON_ONCE(preempt_dynamic_mode == preempt_dynamic_undefined); \ + return preempt_dynamic_mode == preempt_dynamic_##mode; \ + } \ + EXPORT_SYMBOL_GPL(preempt_model_##mode) + +PREEMPT_MODEL_ACCESSOR(none); +PREEMPT_MODEL_ACCESSOR(voluntary); +PREEMPT_MODEL_ACCESSOR(full); + #else /* !CONFIG_PREEMPT_DYNAMIC */ static inline void preempt_dynamic_init(void) { } -- cgit v1.2.3