diff options
| author | Steven Rostedt <srostedt@redhat.com> | 2009-09-01 11:06:29 -0400 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2009-09-04 18:44:22 -0400 |
| commit | 2f26ebd549b9ab55ac756b836ec759c11fe93f81 (patch) | |
| tree | 0f6fb154e2b5e9233a683b3267e5efe862a846f4 /kernel/trace/trace.h | |
| parent | 76f0d07376388f32698ba51b6090a26b90c1342f (diff) | |
tracing: use timestamp to determine start of latency traces
Currently the latency tracers reset the ring buffer. Unfortunately
if a commit is in process (due to a trace event), this can corrupt
the ring buffer. When this happens, the ring buffer will detect
the corruption and then permanently disable the ring buffer.
The bug does not crash the system, but it does prevent further tracing
after the bug is hit.
Instead of reseting the trace buffers, the timestamp of the start of
the trace is used instead. The buffers will still contain the previous
data, but the output will not count any data that is before the
timestamp of the trace.
Note, this only affects the static trace output (trace) and not the
runtime trace output (trace_pipe). The runtime trace output does not
make sense for the latency tracers anyway.
Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace.h')
| -rw-r--r-- | kernel/trace/trace.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index f2af713a8bc..ca070de3622 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -241,6 +241,7 @@ struct trace_array_cpu { unsigned long nice; unsigned long policy; unsigned long rt_priority; + unsigned long skipped_entries; cycle_t preempt_timestamp; pid_t pid; uid_t uid; |