diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2020-05-12 09:44:43 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-05-15 19:52:53 +0200 |
| commit | 0adeeee7dd32b29e2f0d911a48aeac05475766fc (patch) | |
| tree | 5efc34d20d5698a9d55e2eda03bb7298bdb5f1c4 | |
| parent | f03d6326bf505a1187695d467f1e3a33692e65a9 (diff) | |
rcu: Provide __rcu_is_watching()noinstr-rcu-nmi-2020-05-15
Same as rcu_is_watching() but without the preempt_disable/enable() pair
inside the function. It is merked noinstr so it ends up in the
non-instrumentable text section.
This is useful for non-preemptible code especially in the low level entry
section. Using rcu_is_watching() there results in a call to the
preempt_schedule_notrace() thunk which triggers noinstr section warnings in
objtool.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| -rw-r--r-- | include/linux/rcutiny.h | 1 | ||||
| -rw-r--r-- | include/linux/rcutree.h | 1 | ||||
| -rw-r--r-- | kernel/rcu/tree.c | 5 |
3 files changed, 7 insertions, 0 deletions
diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h index 980eb78751d9..c869fb20cc51 100644 --- a/include/linux/rcutiny.h +++ b/include/linux/rcutiny.h @@ -86,6 +86,7 @@ static inline void rcu_scheduler_starting(void) { } static inline void rcu_end_inkernel_boot(void) { } static inline bool rcu_inkernel_boot_has_ended(void) { return true; } static inline bool rcu_is_watching(void) { return true; } +static inline bool __rcu_is_watching(void) { return true; } static inline void rcu_momentary_dyntick_idle(void) { } static inline void kfree_rcu_scheduler_running(void) { } static inline bool rcu_gp_might_be_stalled(void) { return false; } diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index 02016e0aa8eb..9366fa4d0717 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -58,6 +58,7 @@ extern int rcu_scheduler_active __read_mostly; void rcu_end_inkernel_boot(void); bool rcu_inkernel_boot_has_ended(void); bool rcu_is_watching(void); +bool __rcu_is_watching(void); #ifndef CONFIG_PREEMPTION void rcu_all_qs(void); #endif diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 62ee01299386..90c8be22d57a 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -985,6 +985,11 @@ static void rcu_disable_urgency_upon_qs(struct rcu_data *rdp) } } +noinstr bool __rcu_is_watching(void) +{ + return !rcu_dynticks_curr_cpu_in_eqs(); +} + /** * rcu_is_watching - see if RCU thinks that the current CPU is not idle * |