diff options
Diffstat (limited to 'kernel/rcu')
| -rw-r--r-- | kernel/rcu/tree.c | 53 |
1 files changed, 15 insertions, 38 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 6396a3d..fbacc48 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2335,34 +2335,6 @@ rcu_start_gp_advanced(struct rcu_state *rsp, struct rcu_node *rnp, } /* - * Similar to rcu_start_gp_advanced(), but also advance the calling CPU's - * callbacks. Note that rcu_start_gp_advanced() cannot do this because it - * is invoked indirectly from rcu_advance_cbs(), which would result in - * endless recursion -- or would do so if it wasn't for the self-deadlock - * that is encountered beforehand. - * - * Returns true if the grace-period kthread needs to be awakened. - */ -static bool rcu_start_gp(struct rcu_state *rsp) -{ - struct rcu_data *rdp = this_cpu_ptr(rsp->rda); - struct rcu_node *rnp = rcu_get_root(rsp); - bool ret = false; - - /* - * If there is no grace period in progress right now, any - * callbacks we have up to this point will be satisfied by the - * next grace period. Also, advancing the callbacks reduces the - * probability of false positives from cpu_needs_another_gp() - * resulting in pointless grace periods. So, advance callbacks - * then start the grace period! - */ - ret = rcu_advance_cbs(rsp, rnp, rdp) || ret; - ret = rcu_start_gp_advanced(rsp, rnp, rdp) || ret; - return ret; -} - -/* * Report a full set of quiescent states to the specified rcu_state data * structure. Invoke rcu_gp_kthread_wake() to awaken the grace-period * kthread if another grace period is required. Whether we wake @@ -2889,22 +2861,27 @@ __rcu_process_callbacks(struct rcu_state *rsp) unsigned long flags; bool needwake; struct rcu_data *rdp = raw_cpu_ptr(rsp->rda); + struct rcu_node *rnp; WARN_ON_ONCE(!rdp->beenonline); /* Update RCU state based on any recent quiescent states. */ rcu_check_quiescent_state(rsp, rdp); - /* Does this CPU require a not-yet-started grace period? */ - local_irq_save(flags); - if (cpu_needs_another_gp(rsp, rdp)) { - raw_spin_lock_rcu_node(rcu_get_root(rsp)); /* irqs disabled. */ - needwake = rcu_start_gp(rsp); - raw_spin_unlock_irqrestore_rcu_node(rcu_get_root(rsp), flags); - if (needwake) - rcu_gp_kthread_wake(rsp); - } else { - local_irq_restore(flags); + /* No grace period and unregistered callbacks? */ + if (!rcu_gp_in_progress(rsp) && + rcu_segcblist_is_enabled(&rdp->cblist)) { + local_irq_save(flags); + if (rcu_segcblist_restempty(&rdp->cblist, RCU_NEXT_READY_TAIL)) { + local_irq_restore(flags); + } else { + rnp = rdp->mynode; + raw_spin_lock_rcu_node(rnp); /* irqs disabled. */ + needwake = rcu_accelerate_cbs(rsp, rnp, rdp); + raw_spin_unlock_irqrestore_rcu_node(rnp, flags); + if (needwake) + rcu_gp_kthread_wake(rsp); + } } /* If there are callbacks ready, invoke them. */ |
