summaryrefslogtreecommitdiffstats
path: root/kernel/rcu
diff options
context:
space:
mode:
authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2017-09-19 15:36:42 -0700
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2017-10-19 12:13:36 -0700
commit02a7c234e54052101164368ff981bd72f7acdd65 (patch)
tree5819d6d63e9f824a702a4b8e90e87720c2b0fe45 /kernel/rcu
parentb88697810d7c1d102a529990f9071b0f14cfe6df (diff)
downloadlinux-02a7c234e54052101164368ff981bd72f7acdd65.tar.gz
linux-02a7c234e54052101164368ff981bd72f7acdd65.tar.bz2
linux-02a7c234e54052101164368ff981bd72f7acdd65.zip
rcu: Suppress lockdep false-positive ->boost_mtx complaints
RCU priority boosting uses rt_mutex_init_proxy_locked() to initialize an rt_mutex structure in locked state held by some other task. When that other task releases it, lockdep complains (quite accurately, but a bit uselessly) that the other task never acquired it. This complaint can suppress other, more helpful, lockdep complaints, and in any case it is a false positive. This commit therefore switches from rt_mutex_unlock() to rt_mutex_futex_unlock(), thereby avoiding the lockdep annotations. Of course, if lockdep ever learns about rt_mutex_init_proxy_locked(), addtional adjustments will be required. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcu')
-rw-r--r--kernel/rcu/tree_plugin.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 969eae45f05d..1eaab96d1a3c 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -531,7 +531,7 @@ void rcu_read_unlock_special(struct task_struct *t)
/* Unboost if we were boosted. */
if (IS_ENABLED(CONFIG_RCU_BOOST) && drop_boost_mutex)
- rt_mutex_unlock(&rnp->boost_mtx);
+ rt_mutex_futex_unlock(&rnp->boost_mtx);
/*
* If this was the last task on the expedited lists,