Le Tue, Apr 30, 2024 at 11:17:17AM +0200, Valentin Schneider a écrit :
> The context_tracking.state RCU_DYNTICKS subvariable has been renamed to
> RCU_WATCHING, and the 'dynticks' prefix can be dropped without losing any
> meaning.
>
> Suggested-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
> Signed-off-by: Valentin Schneider <vschneid@xxxxxxxxxx>
> ---
> kernel/context_tracking.c | 20 ++++++++++----------
> 1 file changed, 10 insertions(+), 10 deletions(-)
>
> diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c
> index 647939b0befd9..9c8f7b9191cd4 100644
> --- a/kernel/context_tracking.c
> +++ b/kernel/context_tracking.c
> @@ -39,7 +39,7 @@ EXPORT_SYMBOL_GPL(context_tracking);
> #define TPS(x) tracepoint_string(x)
>
> /* Record the current task on dyntick-idle entry. */
> -static __always_inline void rcu_dynticks_task_enter(void)
> +static __always_inline void rcu_task_enter(void)
On a second thought, this should be the reverse. We are not
telling anymore that we are entering dynticks mode from an
RCU-task perspective. We are telling that we are exiting RCU-tasks
because we are in eqs mode (even though this is mostly a concern
for nohz_full here, as idle tasks are entirely quiescent states
but anyway...).
So this should be s/rcu_dynticks_task_enter/rcu_task_exit
> {
> #if defined(CONFIG_TASKS_RCU) && defined(CONFIG_NO_HZ_FULL)
> WRITE_ONCE(current->rcu_tasks_idle_cpu, smp_processor_id());
> @@ -47,7 +47,7 @@ static __always_inline void rcu_dynticks_task_enter(void)
> }
>
> /* Record no current task on dyntick-idle exit. */
> -static __always_inline void rcu_dynticks_task_exit(void)
> +static __always_inline void rcu_task_exit(void)
And s/rcu_dynticks_task_exit/rcu_task_enter
> {
> #if defined(CONFIG_TASKS_RCU) && defined(CONFIG_NO_HZ_FULL)
> WRITE_ONCE(current->rcu_tasks_idle_cpu, -1);
> @@ -55,7 +55,7 @@ static __always_inline void rcu_dynticks_task_exit(void)
> }
>
> /* Turn on heavyweight RCU tasks trace readers on idle/user entry. */
> -static __always_inline void rcu_dynticks_task_trace_enter(void)
> +static __always_inline void rcu_task_trace_enter(void)
The same reverse naming goes for task_trace (even though I can't make
sense right now of what the barrier it implies orders exactly, but that's
another story)
> {
> #ifdef CONFIG_TASKS_TRACE_RCU
> if (IS_ENABLED(CONFIG_TASKS_TRACE_RCU_READ_MB))
> @@ -64,7 +64,7 @@ static __always_inline void rcu_dynticks_task_trace_enter(void)
> }
>
> /* Turn off heavyweight RCU tasks trace readers on idle/user exit. */
> -static __always_inline void rcu_dynticks_task_trace_exit(void)
> +static __always_inline void rcu_task_trace_exit(void)
> {
> #ifdef CONFIG_TASKS_TRACE_RCU
> if (IS_ENABLED(CONFIG_TASKS_TRACE_RCU_READ_MB))
> @@ -87,7 +87,7 @@ static noinstr void ct_kernel_exit_state(int offset)
> * critical sections, and we also must force ordering with the
> * next idle sojourn.
> */
> - rcu_dynticks_task_trace_enter(); // Before ->dynticks update!
> + rcu_task_trace_enter(); // Before ->dynticks update!
s/->dynticks/->state
> seq = ct_state_inc(offset);
> // RCU is no longer watching. Better be in extended quiescent state!
> WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && (seq & CT_RCU_WATCHING));
> @@ -109,7 +109,7 @@ static noinstr void ct_kernel_enter_state(int offset)
> */
> seq = ct_state_inc(offset);
> // RCU is now watching. Better not be in an extended quiescent state!
> - rcu_dynticks_task_trace_exit(); // After ->dynticks update!
> + rcu_task_trace_exit(); // After ->dynticks update!
ditto
Thanks!
