diff options
Diffstat (limited to 'kernel/rcutree_plugin.h')
| -rw-r--r-- | kernel/rcutree_plugin.h | 25 |
1 files changed, 17 insertions, 8 deletions
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index ebd20ee7707..ef2a58c2b9d 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -304,21 +304,25 @@ static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp) * parent is to remove the need for rcu_read_unlock_special() to * make more than two attempts to acquire the target rcu_node's lock. * + * Returns 1 if there was previously a task blocking the current grace + * period on the specified rcu_node structure. + * * The caller must hold rnp->lock with irqs disabled. */ -static void rcu_preempt_offline_tasks(struct rcu_state *rsp, - struct rcu_node *rnp, - struct rcu_data *rdp) +static int rcu_preempt_offline_tasks(struct rcu_state *rsp, + struct rcu_node *rnp, + struct rcu_data *rdp) { int i; struct list_head *lp; struct list_head *lp_root; + int retval = rcu_preempted_readers(rnp); struct rcu_node *rnp_root = rcu_get_root(rsp); struct task_struct *tp; if (rnp == rnp_root) { WARN_ONCE(1, "Last CPU thought to be offlined?"); - return; /* Shouldn't happen: at least one CPU online. */ + return 0; /* Shouldn't happen: at least one CPU online. */ } WARN_ON_ONCE(rnp != rdp->mynode && (!list_empty(&rnp->blocked_tasks[0]) || @@ -342,6 +346,8 @@ static void rcu_preempt_offline_tasks(struct rcu_state *rsp, spin_unlock(&rnp_root->lock); /* irqs remain disabled */ } } + + return retval; } /* @@ -532,12 +538,15 @@ static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp) /* * Because preemptable RCU does not exist, it never needs to migrate - * tasks that were blocked within RCU read-side critical sections. + * tasks that were blocked within RCU read-side critical sections, and + * such non-existent tasks cannot possibly have been blocking the current + * grace period. */ -static void rcu_preempt_offline_tasks(struct rcu_state *rsp, - struct rcu_node *rnp, - struct rcu_data *rdp) +static int rcu_preempt_offline_tasks(struct rcu_state *rsp, + struct rcu_node *rnp, + struct rcu_data *rdp) { + return 0; } /* |