perf: thread is its own parent

[David Ahern <dsahern@gmail.com>]

Don:

In this commit:

commit 363b785f3805a2632eb09a8b430842461c21a640
Author: Don Zickus <dzickus@redhat.com>
Date:   Fri Mar 14 10:43:44 2014 -0400

     perf tools: Speed up thread map generation

you made a thread its own parent when synthesizing fork events:

static int perf_event__synthesize_fork(struct perf_tool *tool,
                                        union perf_event *event, pid_t pid,
                                        pid_t tgid, 
perf_event__handler_t process,
                                        struct machine *machine)
{
         memset(&event->fork, 0, sizeof(event->fork) + 
machine->id_hdr_size);

         event->fork.ppid = tgid;
         event->fork.ptid = tgid;
         event->fork.pid  = tgid;
         event->fork.tid  = pid;
         event->fork.header.type = PERF_RECORD_FORK;


Any particular reason or just an oversight?

David