diff options
Diffstat (limited to 'kernel/rcu')
| -rw-r--r-- | kernel/rcu/tasks.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h index 806160c44b17..3b2f8038064a 100644 --- a/kernel/rcu/tasks.h +++ b/kernel/rcu/tasks.h @@ -1150,14 +1150,28 @@ static void check_all_holdout_tasks_trace(struct list_head *hop, } } +static void rcu_tasks_trace_empty_fn(void *unused) +{ +} + /* Wait for grace period to complete and provide ordering. */ static void rcu_tasks_trace_postgp(struct rcu_tasks *rtp) { + int cpu; bool firstreport; struct task_struct *g, *t; LIST_HEAD(holdouts); long ret; + // Wait for any lingering IPI handlers to complete. Note that + // if a CPU has gone offline or transitioned to userspace in the + // meantime, all IPI handlers should have been drained beforehand. + // Yes, this assumes that CPUs process IPIs in order. If that ever + // changes, there will need to be a recheck and/or timed wait. + for_each_online_cpu(cpu) + if (smp_load_acquire(per_cpu_ptr(&trc_ipi_to_cpu, cpu))) + smp_call_function_single(cpu, rcu_tasks_trace_empty_fn, NULL, 1); + // Remove the safety count. smp_mb__before_atomic(); // Order vs. earlier atomics atomic_dec(&trc_n_readers_need_end); |