diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index b9dad3500041..342f49c3ccc5 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -2814,6 +2814,17 @@ rb_try_to_discard(struct ring_buffer_per_cpu *cpu_buffer, write_stamp, write_stamp - delta)) return 0; + /* + * It's possible that the event time delta is zero + * (has the same time stamp as the previous event) + * in which case write_stamp and before_stamp could + * be the same. In such a case, force before_stamp + * to be different than write_stamp. It doesn't + * matter what it is, as long as its different. + */ + if (!delta) + rb_time_set(&cpu_buffer->before_stamp, 0); + /* * If an event were to come in now, it would see that the * write_stamp and the before_stamp are different, and assume