diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2020-09-29 13:33:40 +0200 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2020-11-20 04:37:17 +0100 |
| commit | d2098b4440981705e844c50254540ba7b5f82795 (patch) | |
| tree | 14d4921af20f7dd5343c79c97f36106270b348bb /kernel/rcu/tree.c | |
| parent | rcu/tree: Make struct kernel_param_ops definitions const (diff) | |
| download | linux-d2098b4440981705e844c50254540ba7b5f82795.tar.xz linux-d2098b4440981705e844c50254540ba7b5f82795.zip | |
rcu,ftrace: Fix ftrace recursion
Kim reported that perf-ftrace made his box unhappy. It turns out that
commit:
ff5c4f5cad33 ("rcu/tree: Mark the idle relevant functions noinstr")
removed one too many notrace qualifiers, probably due to there not being
a helpful comment.
This commit therefore reinstates the notrace and adds a comment to avoid
losing it again.
[ paulmck: Apply Steven Rostedt's feedback on the comment. ]
Fixes: ff5c4f5cad33 ("rcu/tree: Mark the idle relevant functions noinstr")
Reported-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu/tree.c')
| -rw-r--r-- | kernel/rcu/tree.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 5f458e4efc95..d6a015e68649 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1093,8 +1093,11 @@ static void rcu_disable_urgency_upon_qs(struct rcu_data *rdp) * CPU can safely enter RCU read-side critical sections. In other words, * if the current CPU is not in its idle loop or is in an interrupt or * NMI handler, return true. + * + * Make notrace because it can be called by the internal functions of + * ftrace, and making this notrace removes unnecessary recursion calls. */ -bool rcu_is_watching(void) +notrace bool rcu_is_watching(void) { bool ret; |