diff options
Diffstat (limited to 'kernel/trace/ring_buffer.c')
| -rw-r--r-- | kernel/trace/ring_buffer.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index db72969aefa9..988915f035c7 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -3525,6 +3525,9 @@ static void rb_inc_iter(struct ring_buffer_iter *iter) else rb_inc_page(&iter->head_page); + if (rb_page_commit(iter->head_page) & RB_MISSED_EVENTS) + iter->missed_events = -1; + iter->page_stamp = iter->read_stamp = iter->head_page->page->time_stamp; iter->head = 0; iter->next_event = 0; @@ -7061,7 +7064,7 @@ int ring_buffer_read_page(struct trace_buffer *buffer, struct ring_buffer_event *event; struct buffer_data_page *dpage; struct buffer_page *reader; - unsigned long missed_events; + long missed_events; unsigned int commit; unsigned int read; u64 save_timestamp; @@ -7187,6 +7190,8 @@ int ring_buffer_read_page(struct trace_buffer *buffer, local_set(&reader->entries, 0); reader->read = 0; data_page->data = dpage; + if (!missed_events && rb_data_page_commit(dpage) & RB_MISSED_EVENTS) + missed_events = -1; /* * Use the real_end for the data size, @@ -7204,10 +7209,12 @@ int ring_buffer_read_page(struct trace_buffer *buffer, * Set a flag in the commit field if we lost events */ if (missed_events) { - /* If there is room at the end of the page to save the + /* + * If there is room at the end of the page to save the * missed events, then record it there. */ - if (buffer->subbuf_size - commit >= sizeof(missed_events)) { + if (missed_events > 0 && + buffer->subbuf_size - commit >= sizeof(missed_events)) { memcpy(&dpage->data[commit], &missed_events, sizeof(missed_events)); local_add(RB_MISSED_STORED, &dpage->commit); |