diff options
| author | Frederic Weisbecker | 2023-10-27 16:40:47 +0200 |
|---|---|---|
| committer | Frederic Weisbecker | 2023-11-01 22:03:27 +0100 |
| commit | 2be4686d866ad5896f2bb94d82fe892197aea9c7 (patch) | |
| tree | 40353bb0ac735517e5d49aceb9262dca0ae9064b | |
| parent | 85d68222ddc5f4522e456d97d201166acb50f716 (diff) | |
rcu: Introduce rcu_cpu_online()
Export the RCU point of view as to when a CPU is considered offline
(ie: when does RCU consider that a CPU is sufficiently down in the
hotplug process to not feature any possible read side).
This will be used by RCU-tasks whose vision of an offline CPU should
reasonably match the one of RCU core.
Fixes: cff9b2332ab7 ("kernel/sched: Modify initial boot task idle setup")
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
| -rw-r--r-- | kernel/rcu/rcu.h | 2 | ||||
| -rw-r--r-- | kernel/rcu/tree.c | 7 |
2 files changed, 9 insertions, 0 deletions
diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h index 0d866eaa4cc8..b531c33e9545 100644 --- a/kernel/rcu/rcu.h +++ b/kernel/rcu/rcu.h @@ -500,6 +500,7 @@ static inline void rcu_expedite_gp(void) { } static inline void rcu_unexpedite_gp(void) { } static inline void rcu_async_hurry(void) { } static inline void rcu_async_relax(void) { } +static inline bool rcu_cpu_online(int cpu) { return true; } #else /* #ifdef CONFIG_TINY_RCU */ bool rcu_gp_is_normal(void); /* Internal RCU use. */ bool rcu_gp_is_expedited(void); /* Internal RCU use. */ @@ -509,6 +510,7 @@ void rcu_unexpedite_gp(void); void rcu_async_hurry(void); void rcu_async_relax(void); void rcupdate_announce_bootup_oddness(void); +bool rcu_cpu_online(int cpu); #ifdef CONFIG_TASKS_RCU_GENERIC void show_rcu_tasks_gp_kthreads(void); #else /* #ifdef CONFIG_TASKS_RCU_GENERIC */ diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 77e7a0dc722a..c3359f4c8830 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -4216,6 +4216,13 @@ static bool rcu_rdp_cpu_online(struct rcu_data *rdp) return !!(rdp->grpmask & rcu_rnp_online_cpus(rdp->mynode)); } +bool rcu_cpu_online(int cpu) +{ + struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu); + + return rcu_rdp_cpu_online(rdp); +} + #if defined(CONFIG_PROVE_RCU) && defined(CONFIG_HOTPLUG_CPU) /* |