Re: [PATCH 0/9] TRACE_IRQFLAGS wreckage

From: peterz
Date: Fri Aug 21 2020 - 02:54:40 EST


On Thu, Aug 20, 2020 at 07:20:46PM +0200, Marco Elver wrote:
> From 4ec9dd472c978e1eba622fb22bc04e4357f10421 Mon Sep 17 00:00:00 2001
> From: Marco Elver <elver@xxxxxxxxxx>
> Date: Thu, 20 Aug 2020 19:06:09 +0200
> Subject: [PATCH] sched: Turn inline into __always_inline due to noinstr use
>
> is_idle_task() may be used from noinstr functions such as
> irqentry_enter(). Since the compiler is free to not inline regular
> inline functions, switch to using __always_inline.
>
> Signed-off-by: Marco Elver <elver@xxxxxxxxxx>

Fair enough I suppose; didn't that generate an objtool warning on your
build? (of course that requires PARAVIRT=n, I should get back to fixing
that)

> ---
> include/linux/sched.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/linux/sched.h b/include/linux/sched.h
> index 93ecd930efd3..afe01e232935 100644
> --- a/include/linux/sched.h
> +++ b/include/linux/sched.h
> @@ -1666,7 +1666,7 @@ extern struct task_struct *idle_task(int cpu);
> *
> * Return: 1 if @p is an idle task. 0 otherwise.
> */
> -static inline bool is_idle_task(const struct task_struct *p)
> +static __always_inline bool is_idle_task(const struct task_struct *p)
> {
> return !!(p->flags & PF_IDLE);
> }
> --
> 2.28.0.297.g1956fa8f8d-goog