On Wed, Feb 08, 2017 at 11:25:05AM -0600, Tom Zanussi wrote: > Add support for a timestamp event field. This is actually a 'pseudo-' > event field in that it behaves like it's part of the event record, but > is really part of the corresponding ring buffer event. > > To make use of the timestamp field, users can specify "common_timestamp" > as a field name for any histogram. Note that this doesn't make much > sense on its own either as either a key or value, but needs to be > supported even so, since follow-on patches will add support for making > use of this field in time deltas. > > Note that the use of this field requires the ring buffer be put into > TIME_EXTEND_ABS mode, which saves the complete timestamp for each > event rather than an offset. This mode will be enabled if and only if > a histogram makes use of the "common_timestamp" field. > > Signed-off-by: Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx> > --- > kernel/trace/trace_events_hist.c | 85 +++++++++++++++++++++++++++++----------- > 1 file changed, 62 insertions(+), 23 deletions(-) > > diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c > index 4e70872..8d7f7dd 100644 > --- a/kernel/trace/trace_events_hist.c > +++ b/kernel/trace/trace_events_hist.c > @@ -88,6 +88,12 @@ static u64 hist_field_log2(struct hist_field *hist_field, void *event, > return (u64) ilog2(roundup_pow_of_two(val)); > } > > +static u64 hist_field_timestamp(struct hist_field *hist_field, void *event, > + struct ring_buffer_event *rbe) > +{ > + return ring_buffer_event_time_stamp(rbe); > +} > + > #define DEFINE_HIST_FIELD_FN(type) \ > static u64 hist_field_##type(struct hist_field *hist_field, \ > void *event, \ > @@ -134,6 +140,7 @@ enum hist_field_flags { > HIST_FIELD_FL_SYSCALL = 128, > HIST_FIELD_FL_STACKTRACE = 256, > HIST_FIELD_FL_LOG2 = 512, > + HIST_FIELD_FL_TIMESTAMP = 1024, > }; > > struct hist_trigger_attrs { > @@ -158,6 +165,7 @@ struct hist_trigger_data { > struct trace_event_file *event_file; > struct hist_trigger_attrs *attrs; > struct tracing_map *map; > + bool enable_timestamps; > }; > > static const char *hist_field_name(struct hist_field *field) > @@ -404,6 +412,7 @@ static struct hist_field *create_hist_field(struct ftrace_event_field *field, > hist_field = kzalloc(sizeof(struct hist_field), GFP_KERNEL); > if (!hist_field) > return NULL; > + hist_field->is_signed = false; I think it's not needed since hist_field is allocated by kzalloc(). Also I cannot find where ->is_signed is set. > > if (flags & HIST_FIELD_FL_HITCOUNT) { > hist_field->fn = hist_field_counter; > @@ -423,6 +432,12 @@ static struct hist_field *create_hist_field(struct ftrace_event_field *field, > goto out; > } > > + if (flags & HIST_FIELD_FL_TIMESTAMP) { > + hist_field->fn = hist_field_timestamp; > + hist_field->size = sizeof(u64); > + goto out; > + } > + > if (WARN_ON_ONCE(!field)) > goto out; > [SNIP] > @@ -1520,6 +1557,8 @@ static int hist_register_trigger(char *glob, struct event_trigger_ops *ops, > > update_cond_flag(file); > > + tracing_set_time_stamp_abs(file->tr, true); > + Hmm.. does it makes all events using absolute timestamp? Where is it turned off? Thanks, Namhyung > if (trace_event_trigger_enable_disable(file, 1) < 0) { > list_del_rcu(&data->list); > update_cond_flag(file); > -- > 1.9.3 > -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html