diff options
Diffstat (limited to 'kernel/trace/ring_buffer.c')
| -rw-r--r-- | kernel/trace/ring_buffer.c | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index b9dad3500041..68744c51517e 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -2815,6 +2815,17 @@ rb_try_to_discard(struct ring_buffer_per_cpu *cpu_buffer, 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 * that this event just added itself before updating @@ -3307,9 +3318,13 @@ static void check_buffer(struct ring_buffer_per_cpu *cpu_buffer, goto out; } atomic_inc(&cpu_buffer->record_disabled); - pr_warn("[CPU: %d]TIME DOES NOT MATCH expected:%lld actual:%lld delta:%lld after:%lld\n", - cpu_buffer->cpu, - ts + info->delta, info->ts, info->delta, info->after); + /* There's some cases in boot up that this can happen */ + WARN_ON_ONCE(system_state != SYSTEM_BOOTING); + pr_warn("[CPU: %d]TIME DOES NOT MATCH expected:%lld actual:%lld delta:%lld before:%lld after:%lld%s\n", + cpu_buffer->cpu, + ts + info->delta, info->ts, info->delta, + info->before, info->after, + full ? " (full)" : ""); dump_buffer_page(bpage, info, tail); atomic_dec(&ts_dump); /* Do not re-enable checking */ |