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| author |   Thomas Gleixner <tglx@linutronix.de> | 2020-05-12 09:44:43 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-05-19 15:51:21 +0200 |
| commit | b1fcf9b83c4149c63d1e0c699e85f93cbe28e211 (patch) | |
| tree | 39a5dc1ef4133da88b638dd6b432d0c8d85d51cb /kernel/rcu | |
| parent | rcu: Provide rcu_irq_exit_preempt() (diff) | |
| download | linux-dev-b1fcf9b83c4149c63d1e0c699e85f93cbe28e211.tar.xz linux-dev-b1fcf9b83c4149c63d1e0c699e85f93cbe28e211.zip | |
rcu: Provide __rcu_is_watching()
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>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200512213810.518709291@linutronix.de
Diffstat (limited to 'kernel/rcu')
| -rw-r--r-- | kernel/rcu/tree.c | 5 |
1 files changed, 5 insertions, 0 deletions
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 * |