| From: Tom Zanussi <tom.zanussi@linux.intel.com> |
| Date: Mon, 15 Jan 2018 20:52:09 -0600 |
| Subject: [PATCH 35/37] tracing: Increase trace_recursive_lock() limit for |
| synthetic events |
| |
| Synthetic event generation needs to happen while the current event is |
| still in progress, so add 1 to the trace_recursive_lock() recursion |
| limit to account for that. |
| |
| Because we also want to allow for the possibility of a synthetic event |
| being generated from another synthetic event, add an additional |
| increment for that as well. |
| |
| Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> |
| Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> |
| --- |
| kernel/trace/ring_buffer.c | 10 +++++----- |
| 1 file changed, 5 insertions(+), 5 deletions(-) |
| |
| --- a/kernel/trace/ring_buffer.c |
| +++ b/kernel/trace/ring_buffer.c |
| @@ -2593,16 +2593,16 @@ rb_wakeups(struct ring_buffer *buffer, s |
| * IRQ context |
| * NMI context |
| * |
| - * If for some reason the ring buffer starts to recurse, we |
| - * only allow that to happen at most 4 times (one for each |
| - * context). If it happens 5 times, then we consider this a |
| - * recusive loop and do not let it go further. |
| + * If for some reason the ring buffer starts to recurse, we only allow |
| + * that to happen at most 6 times (one for each context, plus possibly |
| + * two levels of synthetic event generation). If it happens 7 times, |
| + * then we consider this a recusive loop and do not let it go further. |
| */ |
| |
| static __always_inline int |
| trace_recursive_lock(struct ring_buffer_per_cpu *cpu_buffer) |
| { |
| - if (cpu_buffer->current_context >= 4) |
| + if (cpu_buffer->current_context >= 6) |
| return 1; |
| |
| cpu_buffer->current_context++; |