diff options
| author | Steven Rostedt <srostedt@redhat.com> | 2009-03-02 13:53:59 -0500 |
|---|---|---|
| committer | Steven Rostedt <srostedt@redhat.com> | 2009-03-02 14:27:27 -0500 |
| commit | 981d081ec8b958b7d962ee40d433581a55d40fc5 (patch) | |
| tree | 366aa5da7dc98cc2354002946e6f19ec60c02301 /kernel/trace/trace_events_stage_2.h | |
| parent | f9520750c4c9924c14325cd951efae5fae58104c (diff) | |
tracing: add format file to describe event struct fields
This patch adds the "format" file to the trace point event directory.
This is based off of work by Tom Zanussi, in which a file is exported
to be tread from user land such that a user space app may read the
binary record stored in the ring buffer.
# cat /debug/tracing/events/sched/sched_switch/format
field:pid_t prev_pid; offset:12; size:4;
field:int prev_prio; offset:16; size:4;
field special:char next_comm[TASK_COMM_LEN]; offset:20; size:16;
field:pid_t next_pid; offset:36; size:4;
field:int next_prio; offset:40; size:4;
Idea-from: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Diffstat (limited to 'kernel/trace/trace_events_stage_2.h')
| -rw-r--r-- | kernel/trace/trace_events_stage_2.h | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/kernel/trace/trace_events_stage_2.h b/kernel/trace/trace_events_stage_2.h index dc79fe3a2ec..3a80ea4e92c 100644 --- a/kernel/trace/trace_events_stage_2.h +++ b/kernel/trace/trace_events_stage_2.h @@ -74,3 +74,55 @@ ftrace_raw_output_##call(struct trace_iterator *iter, int flags) \ } #include <trace/trace_event_types.h> + +/* + * Setup the showing format of trace point. + * + * int + * ftrace_format_##call(struct trace_seq *s) + * { + * struct ftrace_raw_##call field; + * int ret; + * + * ret = trace_seq_printf(s, #type " " #item ";" + * " size:%d; offset:%d;\n", + * sizeof(field.type), + * offsetof(struct ftrace_raw_##call, + * item)); + * + * } + */ + +#undef TRACE_FIELD +#define TRACE_FIELD(type, item, assign) \ + ret = trace_seq_printf(s, "\tfield:" #type " " #item ";\t" \ + "offset:%lu;\tsize:%lu;\n", \ + offsetof(typeof(field), item), \ + sizeof(field.item)); \ + if (!ret) \ + return 0; + + +#undef TRACE_FIELD_SPECIAL +#define TRACE_FIELD_SPECIAL(type_item, item, cmd) \ + ret = trace_seq_printf(s, "\tfield special:" #type_item ";\t" \ + "offset:%lu;\tsize:%lu;\n", \ + offsetof(typeof(field), item), \ + sizeof(field.item)); \ + if (!ret) \ + return 0; + +#undef TRACE_EVENT_FORMAT +#define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt) \ +int \ +ftrace_format_##call(struct trace_seq *s) \ +{ \ + struct ftrace_raw_##call field; \ + int ret; \ + \ + tstruct; \ + \ + return ret; \ +} + +#include <trace/trace_event_types.h> |