tracing: Add tracing_event_time_stamp() API

Add a tracing_event_time_stamp() API that checks if the event passed in is
not on the ring buffer but a pointer to the per CPU trace_buffered_event
which does not have its time stamp set yet.

If it is a pointer to the trace_buffered_event, then just return the
current time stamp that the ring buffer would produce.

Otherwise, return the time stamp from the event.

Link: https://lkml.kernel.org/r/20210316164114.131996180@goodmis.org

Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This commit is contained in:
Steven Rostedt (VMware) 2021-03-16 12:41:07 -04:00
parent a948c69d6f
commit d8279bfc5e
2 changed files with 9 additions and 0 deletions

View File

@ -6972,6 +6972,14 @@ static int tracing_time_stamp_mode_open(struct inode *inode, struct file *file)
return ret;
}
u64 tracing_event_time_stamp(struct trace_buffer *buffer, struct ring_buffer_event *rbe)
{
if (rbe == this_cpu_read(trace_buffered_event))
return ring_buffer_time_stamp(buffer, smp_processor_id());
return ring_buffer_event_time_stamp(buffer, rbe);
}
/*
* Set or disable using the per CPU trace_buffer_event when possible.
*/

View File

@ -372,6 +372,7 @@ extern int tracing_check_open_get_tr(struct trace_array *tr);
extern struct trace_array *trace_array_find(const char *instance);
extern struct trace_array *trace_array_find_get(const char *instance);
extern u64 tracing_event_time_stamp(struct trace_buffer *buffer, struct ring_buffer_event *rbe);
extern int tracing_set_filter_buffering(struct trace_array *tr, bool set);
extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);