diff options
| -rw-r--r-- | include/linux/srcu.h | 21 |
1 files changed, 3 insertions, 18 deletions
diff --git a/include/linux/srcu.h b/include/linux/srcu.h index ae3ee39..04f4121 100644 --- a/include/linux/srcu.h +++ b/include/linux/srcu.h @@ -151,25 +151,14 @@ void srcu_barrier(struct srcu_struct *sp); * Checks debug_lockdep_rcu_enabled() to prevent false positives during boot * and while lockdep is disabled. * - * Note that if the CPU is in the idle loop from an RCU point of view - * (ie: that we are in the section between rcu_idle_enter() and - * rcu_idle_exit()) then srcu_read_lock_held() returns false even if - * the CPU did an srcu_read_lock(). The reason for this is that RCU - * ignores CPUs that are in such a section, considering these as in - * extended quiescent state, so such a CPU is effectively never in an - * RCU read-side critical section regardless of what RCU primitives it - * invokes. This state of affairs is required --- we need to keep an - * RCU-free window in idle where the CPU may possibly enter into low - * power mode. This way we can notice an extended quiescent state to - * other CPUs that started a grace period. Otherwise we would delay any - * grace period as long as we run in the idle task. + * Note that SRCU is based on its own statemachine and it doesn't + * relies on normal RCU, it can be called from the CPU which + * is in the idle loop from an RCU point of view or offline. */ static inline int srcu_read_lock_held(struct srcu_struct *sp) { if (!debug_lockdep_rcu_enabled()) return 1; - if (rcu_is_cpu_idle()) - return 0; return lock_is_held(&sp->dep_map); } @@ -231,8 +220,6 @@ static inline int srcu_read_lock(struct srcu_struct *sp) __acquires(sp) int retval = __srcu_read_lock(sp); rcu_lock_acquire(&(sp)->dep_map); - rcu_lockdep_assert(!rcu_is_cpu_idle(), - "srcu_read_lock() used illegally while idle"); return retval; } @@ -246,8 +233,6 @@ static inline int srcu_read_lock(struct srcu_struct *sp) __acquires(sp) static inline void srcu_read_unlock(struct srcu_struct *sp, int idx) __releases(sp) { - rcu_lockdep_assert(!rcu_is_cpu_idle(), - "srcu_read_unlock() used illegally while idle"); rcu_lock_release(&(sp)->dep_map); __srcu_read_unlock(sp, idx); } |