diff options
| author | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2020-03-17 17:32:32 -0400 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2020-03-27 16:39:01 -0400 |
| commit | c9b7a4a72ff64e67b7e877a99fd652230dc26058 (patch) | |
| tree | 52c419fb90561dd42e81011c073e6851020e6afd /kernel/trace/trace.c | |
| parent | 06e0a548bad0f43a21e036db018e4dadb501ce8b (diff) | |
| download | linux-next-c9b7a4a72ff64e67b7e877a99fd652230dc26058.tar.gz | |
ring-buffer/tracing: Have iterator acknowledge dropped events
Have the ring_buffer_iterator set a flag if events were dropped as it were
to go and peek at the next event. Have the trace file display this fact if
it happened with a "LOST EVENTS" message.
Link: http://lkml.kernel.org/r/20200317213417.045858900@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace.c')
| -rw-r--r-- | kernel/trace/trace.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 650fa81fffe8..5e634b9c1e0a 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3388,11 +3388,15 @@ peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts, struct ring_buffer_event *event; struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, cpu); - if (buf_iter) + if (buf_iter) { event = ring_buffer_iter_peek(buf_iter, ts); - else + if (lost_events) + *lost_events = ring_buffer_iter_dropped(buf_iter) ? + (unsigned long)-1 : 0; + } else { event = ring_buffer_peek(iter->array_buffer->buffer, cpu, ts, lost_events); + } if (event) { iter->ent_size = ring_buffer_event_length(event); @@ -4005,8 +4009,12 @@ enum print_line_t print_trace_line(struct trace_iterator *iter) enum print_line_t ret; if (iter->lost_events) { - trace_seq_printf(&iter->seq, "CPU:%d [LOST %lu EVENTS]\n", - iter->cpu, iter->lost_events); + if (iter->lost_events == (unsigned long)-1) + trace_seq_printf(&iter->seq, "CPU:%d [LOST EVENTS]\n", + iter->cpu); + else + trace_seq_printf(&iter->seq, "CPU:%d [LOST %lu EVENTS]\n", + iter->cpu, iter->lost_events); if (trace_seq_has_overflowed(&iter->seq)) return TRACE_TYPE_PARTIAL_LINE; } |