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| author |   Paul E. McKenney <paulmck@kernel.org> | 2019-10-10 09:05:27 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2019-12-09 12:37:50 -0800 |
| commit | 03bd2983d7a9f898fd89f8f7215c3e56732d8ecd (patch) | |
| tree | 7e0795b0f8be3c7e9a507b2746a49ea2f5ef8819 /kernel | |
| parent | rcu: Avoid data-race in rcu_gp_fqs_check_wake() (diff) | |
| download | linux-dev-03bd2983d7a9f898fd89f8f7215c3e56732d8ecd.tar.xz linux-dev-03bd2983d7a9f898fd89f8f7215c3e56732d8ecd.zip | |
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')
| -rw-r--r-- | kernel/rcu/tree_plugin.h | 4 |
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) && |