introduce -s option for simple event tracing

Examples:

ktap -s "syscalls:*"
ktap -s "*:*"

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
change trace block syntax: remove eventdef string quotation marks

This will make trace block syntax be more simpler, and
easy to write one-liner in command line.

Example:

Before patch:
	trace "syscalls:*" {
		print(argevent)
	}

After patch:
	trace syscalls:* {
		print(argevent)
	}

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
fix ktap -s option for new trace block syntax

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
update bench testcase to newest trace block syntax

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
add more references into doc/references.txt

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
introduce new timer block syntax

This change bring more clean timer block syntax

Before:
	timer.s(1, function () {
		print("time out")
	})

After:
	tick-1s {
		print("time out")
	}

Note that profile still don't supported, fix it soon.

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
call kp_exit_timers before probe_exit

Make sure all timer destroyed before execute trace_end closure

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
remove irq disable in kp_exit_timers

There don't have good reason to disable irq when destroy timers.

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
support profile-n

unlike with tick-n, profile-n fire timer interrupt in every cpu.
user can use specific cpu to profile:
	ktap -C cpu -e "profile-10us {}"

Possible usage:
	profile-1s { ... }
	profile-1ms { ... }
	profile-10us { ... }

This patch also introduce kp_state recursion context, for disable
tracing when execute timer closure.

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
move mainthread stack initization out of kp_newthread

This will make kp_newthread be a little more faster.

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
add timer example into README

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
fix a kernel crash in histogram

forgot to set value of table array in thr data

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
add sample script softirq_timing.kp

This script is purpose for output average execution time of every softirq

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
minor fix in scripts/function_time.kp

check self[tid()] as nil, instead of 0

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
update README

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
print ktap string properly in dump_function
coding style cleanup in main.c
reorganize sample scripts in scripts/ direcotry

Organize those scripts by subsystems and technical domain.

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
user ',' as event separator in eventdef

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>
update scripts/io/kprobes-do-sys-open.kp

This sample script demostrate how to access function arguments
using kprobe.

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@gmail.com>