1 files changed, 14 insertions, 0 deletions

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 644a8b533e1d..5d2f07d6746c 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -192,6 +192,20 @@ struct trace_array {
         bool                    allocated_snapshot;
         unsigned long           max_latency;
 #endif
+        /*
+         * max_lock is used to protect the swapping of buffers
+         * when taking a max snapshot. The buffers themselves are
+         * protected by per_cpu spinlocks. But the action of the swap
+         * needs its own lock.
+         *
+         * This is defined as a arch_spinlock_t in order to help
+         * with performance when lockdep debugging is enabled.
+         *
+         * It is also used in other places outside the update_max_tr
+         * so it needs to be defined outside of the
+         * CONFIG_TRACER_MAX_TRACE.
+         */
+        arch_spinlock_t         max_lock;
         int                     buffer_disabled;
 #ifdef CONFIG_FTRACE_SYSCALLS
         int                     sys_refcount_enter;