On Thu, Sep 28, 2017 at 08:45:16PM +0800, Jin Yao wrote: SNIP
> + return ret; > + > + return do_write(ff, &evlist->last_sample_time, > + sizeof(evlist->last_sample_time)); > +} > + > static void print_hostname(struct feat_fd *ff, FILE *fp) > { > fprintf(fp, "# hostname : %s\n", ff->ph->env.hostname); > @@ -1506,6 +1520,19 @@ static void print_group_desc(struct feat_fd *ff, FILE > *fp) > } > } > > +static void print_sample_time(struct feat_fd *ff, FILE *fp) > +{ > + struct perf_session *session; > + > + session = container_of(ff->ph, struct perf_session, header); > + > + fprintf(fp, "# time of first sample : %" PRIu64 "\n", > + session->evlist->first_sample_time); > + > + fprintf(fp, "# time of last sample : %" PRIu64 "\n", > + session->evlist->last_sample_time); this could be done in some follow up patch, but could we display this in some human readable way.. # time of first sample : 218077073264620 # time of last sample : 218077073395488 jirka