diff options
Diffstat (limited to 'kernel/rcu/tree_plugin.h')
| -rw-r--r-- | kernel/rcu/tree_plugin.h | 88 |
1 files changed, 0 insertions, 88 deletions
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index ff1cd4e1188d..695071dd1e9c 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -681,84 +681,6 @@ void synchronize_rcu(void) } EXPORT_SYMBOL_GPL(synchronize_rcu); -/* - * Remote handler for smp_call_function_single(). If there is an - * RCU read-side critical section in effect, request that the - * next rcu_read_unlock() record the quiescent state up the - * ->expmask fields in the rcu_node tree. Otherwise, immediately - * report the quiescent state. - */ -static void sync_rcu_exp_handler(void *info) -{ - struct rcu_data *rdp; - struct rcu_state *rsp = info; - struct task_struct *t = current; - - /* - * Within an RCU read-side critical section, request that the next - * rcu_read_unlock() report. Unless this RCU read-side critical - * section has already blocked, in which case it is already set - * up for the expedited grace period to wait on it. - */ - if (t->rcu_read_lock_nesting > 0 && - !t->rcu_read_unlock_special.b.blocked) { - t->rcu_read_unlock_special.b.exp_need_qs = true; - return; - } - - /* - * We are either exiting an RCU read-side critical section (negative - * values of t->rcu_read_lock_nesting) or are not in one at all - * (zero value of t->rcu_read_lock_nesting). Or we are in an RCU - * read-side critical section that blocked before this expedited - * grace period started. Either way, we can immediately report - * the quiescent state. - */ - rdp = this_cpu_ptr(rsp->rda); - rcu_report_exp_rdp(rsp, rdp, true); -} - -/** - * synchronize_rcu_expedited - Brute-force RCU grace period - * - * Wait for an RCU-preempt grace period, but expedite it. The basic - * idea is to IPI all non-idle non-nohz online CPUs. The IPI handler - * checks whether the CPU is in an RCU-preempt critical section, and - * if so, it sets a flag that causes the outermost rcu_read_unlock() - * to report the quiescent state. On the other hand, if the CPU is - * not in an RCU read-side critical section, the IPI handler reports - * the quiescent state immediately. - * - * Although this is a greate improvement over previous expedited - * implementations, it is still unfriendly to real-time workloads, so is - * thus not recommended for any sort of common-case code. In fact, if - * you are using synchronize_rcu_expedited() in a loop, please restructure - * your code to batch your updates, and then Use a single synchronize_rcu() - * instead. - */ -void synchronize_rcu_expedited(void) -{ - struct rcu_state *rsp = rcu_state_p; - unsigned long s; - - /* If expedited grace periods are prohibited, fall back to normal. */ - if (rcu_gp_is_normal()) { - wait_rcu_gp(call_rcu); - return; - } - - s = rcu_exp_gp_seq_snap(rsp); - if (exp_funnel_lock(rsp, s)) - return; /* Someone else did our work for us. */ - - /* Initialize the rcu_node tree in preparation for the wait. */ - sync_rcu_exp_select_cpus(rsp, sync_rcu_exp_handler); - - /* Wait for ->blkd_tasks lists to drain, then wake everyone up. */ - rcu_exp_wait_wake(rsp, s); -} -EXPORT_SYMBOL_GPL(synchronize_rcu_expedited); - /** * rcu_barrier - Wait until all in-flight call_rcu() callbacks complete. * @@ -883,16 +805,6 @@ static void rcu_preempt_check_callbacks(void) } /* - * Wait for an rcu-preempt grace period, but make it happen quickly. - * But because preemptible RCU does not exist, map to rcu-sched. - */ -void synchronize_rcu_expedited(void) -{ - synchronize_sched_expedited(); -} -EXPORT_SYMBOL_GPL(synchronize_rcu_expedited); - -/* * Because preemptible RCU does not exist, rcu_barrier() is just * another name for rcu_barrier_sched(). */ |