Allow a user to select which fields to print to stdout for event data.
Options include comm (command name), tid (thread id), pid (process id),
time (perf timestamp), cpu, event (for event name), and trace (for
trace data).

Default is set to maintain compatibility with current output; this
feature does alter output format slightly -- no '-' between command
and pid/tid.

Thanks to Frederic Weisbecker for detailed suggestions on this approach.

Examples (output compressed)

1. trace, default format

perf record -ga -e sched:sched_switch
perf script

swapper    0 [000] 537.037184: sched_switch: prev_comm=swapper prev_pid=0...
   sshd 1675 [000] 537.037309: sched_switch: prev_comm=sshd prev_pid=1675...
netstat 1692 [001] 537.038664: sched_switch: prev_comm=netstat prev_pid=1692...

2. trace, custom format

perf record -ga -e sched:sched_switch
perf script -f comm,pid,time,trace     <--- omitting cpu and event name

swapper    0 537.037184: prev_comm=swapper prev_pid=0 prev_prio=120 ...
   sshd 1675 537.037309: prev_comm=sshd prev_pid=1675 prev_prio=120 ...
netstat 1692 537.038664: prev_comm=netstat prev_pid=1692 prev_prio=120 ...
Acked-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <1299734608-5223-5-git-send-email-daahern@cisco.com>
Signed-off-by: NDavid Ahern <daahern@cisco.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Free the perf trace name space and rename the trace to 'script' which is a
better match for the scripting engine.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Add documentation describing new 'perf trace' command changes
e.g. <command> handling and live-mode/top variants.
Signed-off-by: NTom Zanussi <tom.zanussi@linux.intel.com>
Acked-by: NArnaldo Carvalho de Melo <acme@ghostprotocols.net>

Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Also small update to perf-trace-perl and perf-trace docs.
Signed-off-by: NTom Zanussi <tzanussi@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Keiichi KII <k-keiichi@bx.jp.nec.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <1264580883-15324-13-git-send-email-tzanussi@gmail.com>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>

'perf trace -s list' prints a list of the supported scripting
languages.  One problem with it is that it falls through and prints
the trace as well.  The use of 'list' for this also makes it easy to
confuse with 'perf trace -l', used for listing available scripts.  So
change 'perf trace -s list' to 'perf trace -s lang' and fixes the
fall-through problem.
Signed-off-by: NTom Zanussi <tzanussi@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Keiichi KII <k-keiichi@bx.jp.nec.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <1264580883-15324-2-git-send-email-tzanussi@gmail.com>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>

Update the perf-trace page with new and missing options and
remove some unused ones.
Signed-off-by: NTom Zanussi <tzanussi@gmail.com>
Cc: fweisbec@gmail.com
Cc: rostedt@goodmis.org
LKML-Reference: <1260867220-15699-7-git-send-email-tzanussi@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Adds perf-trace-perl Documentation and a link to it from the
perf-trace page.
Signed-off-by: NTom Zanussi <tzanussi@gmail.com>
Cc: fweisbec@gmail.com
Cc: rostedt@goodmis.org
Cc: anton@samba.org
Cc: hch@infradead.org
LKML-Reference: <1259133352-23685-7-git-send-email-tzanussi@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This turn-key tool allows scheduler measurements to be
conducted and the results be displayed numerically.

First baby step towards that goal: clone the new command off of
perf trace.

Fix a few other details along the way:

 - add (minimal) perf trace documentation

 - reorder a few places

 - list perf trace in the mainporcelain list as well
   as it's a very useful utility.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>