diff options
Diffstat (limited to 'kernel/trace/trace.h')
| -rw-r--r-- | kernel/trace/trace.h | 14 |
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; |