perf_session__findnew
t = perf_session__findnew(session, st->addr);
t = perf_session__findnew(session, st->tid);
t = perf_session__findnew(session, pid);
t = perf_session__findnew(session, pid);
struct thread *perf_session__findnew(struct perf_session *session, pid_t pid);