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authorPaul E. McKenney <paulmck@kernel.org>2019-10-10 09:05:27 -0700
committerPaul E. McKenney <paulmck@kernel.org>2019-12-09 12:37:50 -0800
commit03bd2983d7a9f898fd89f8f7215c3e56732d8ecd (patch)
tree7e0795b0f8be3c7e9a507b2746a49ea2f5ef8819 /kernel/rcu
parent6935c3983b246d5fbfebd3b891c825e65c118f2d (diff)
downloadlinux-03bd2983d7a9f898fd89f8f7215c3e56732d8ecd.tar.bz2
rcu: Use lockdep rather than comment to enforce lock held
The rcu_preempt_check_blocked_tasks() function has a comment that states that the rcu_node structure's ->lock must be held, which might be informative, but which carries little weight if not read. This commit therefore removes this comment in favor of raw_lockdep_assert_held_rcu_node(), which will complain quite visibly if the required lock is not held. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu')
-rw-r--r--kernel/rcu/tree_plugin.h4
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index fe5f44811761..ed54d36465e2 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -648,8 +648,7 @@ static void rcu_read_unlock_special(struct task_struct *t)
* Check that the list of blocked tasks for the newly completed grace
* period is in fact empty. It is a serious bug to complete a grace
* period that still has RCU readers blocked! This function must be
- * invoked -before- updating this rnp's ->gp_seq, and the rnp's ->lock
- * must be held by the caller.
+ * invoked -before- updating this rnp's ->gp_seq.
*
* Also, if there are blocked tasks on the list, they automatically
* block the newly created grace period, so set up ->gp_tasks accordingly.
@@ -659,6 +658,7 @@ static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp)
struct task_struct *t;
RCU_LOCKDEP_WARN(preemptible(), "rcu_preempt_check_blocked_tasks() invoked with preemption enabled!!!\n");
+ raw_lockdep_assert_held_rcu_node(rnp);
if (WARN_ON_ONCE(rcu_preempt_blocked_readers_cgp(rnp)))
dump_blkd_tasks(rnp, 10);
if (rcu_preempt_has_tasks(rnp) &&