Re: [PATCH v3 07/22] rcu: Mark rcu_dynticks_curr_cpu_in_eqs() inline

Paul E. McKenney
2020-02-19T16:39:36Z

On Wed, Feb 19, 2020 at 03:47:31PM +0100, Peter Zijlstra wrote:
> Since rcu_is_watching() is notrace (and needs to be, as it can be
> called from the tracers), make sure everything it in turn calls is
> notrace too.
>
> To that effect, mark rcu_dynticks_curr_cpu_in_eqs() inline, which
> implies notrace, as the function is tiny.
>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>

There was some controversy over inline vs. notrace, leading me to
ask whether we should use both inline and notrace here. ;-)

Assuming that the usual tracing suspects are OK with it:

Reviewed-by: Paul E. McKenney <paulmck@kernel.org>

> ---
> kernel/rcu/tree.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> --- a/kernel/rcu/tree.c
> +++ b/kernel/rcu/tree.c
> @@ -294,7 +294,7 @@ static void rcu_dynticks_eqs_online(void
> *
> * No ordering, as we are sampling CPU-local information.
> */
> -static bool rcu_dynticks_curr_cpu_in_eqs(void)
> +static inline bool rcu_dynticks_curr_cpu_in_eqs(void)
> {
> struct rcu_data *rdp = this_cpu_ptr(&rcu_data);
>
>
>