rcu: Properly initialize ->boost_tasks on CPU offline

When rcu_preempt_offline_tasks() clears tasks from a leaf rcu_node
structure, it does not NULL out the structure's ->boost_tasks field.
This commit therefore fixes this issue.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
This commit is contained in:
Paul E. McKenney 2012-07-27 13:41:47 -07:00 committed by Paul E. McKenney
parent 818615c4cd
commit 1e3fd2b38c

View File

@ -584,8 +584,11 @@ static int rcu_preempt_offline_tasks(struct rcu_state *rsp,
raw_spin_unlock(&rnp_root->lock); /* irqs still disabled */
}
rnp->gp_tasks = NULL;
rnp->exp_tasks = NULL;
#ifdef CONFIG_RCU_BOOST
/* In case root is being boosted and leaf is not. */
rnp->boost_tasks = NULL;
/* In case root is being boosted and leaf was not. */
raw_spin_lock(&rnp_root->lock); /* irqs already disabled */
if (rnp_root->boost_tasks != NULL &&
rnp_root->boost_tasks != rnp_root->gp_tasks)
@ -593,8 +596,6 @@ static int rcu_preempt_offline_tasks(struct rcu_state *rsp,
raw_spin_unlock(&rnp_root->lock); /* irqs still disabled */
#endif /* #ifdef CONFIG_RCU_BOOST */
rnp->gp_tasks = NULL;
rnp->exp_tasks = NULL;
return retval;
}