[PATCH v8 35/37] tracing: Increase trace_recursive_lock() limit for synthetic events
From: Tom Zanussi <hidden>
Date: 2017-12-21 16:06:35
Also in:
lkml
Subsystem:
the rest, tracing · Maintainers:
Linus Torvalds, Steven Rostedt, Masami Hiramatsu
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 <redacted> --- kernel/trace/ring_buffer.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index dd35424..2375c5c 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c@@ -2581,16 +2581,16 @@ static void rb_commit(struct ring_buffer_per_cpu *cpu_buffer, * 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++;
--
1.9.3