[ltt-dev] Make lttctl use new interface

[Zhaolei]

Mathieu Desnoyers ??:
> * Zhaolei (zhaolei at cn.fujitsu.com) wrote:
>> Hi, Mathieu
>>
>> I modified lttctl for support debugfs-based ltt-trace-control.
>>
>> This patch only modified interior method of control ltt trace,
>> so command args are not changed.
>>
>> We can use this code without modify our user-manual, and lttv need not change
>> too.
>>
>> But personaly, I'd like to design a set of new command arguments for lttctl in
>> next step, for support each-channel buffer and overwrite control.
>> And old cmd-args as -X, -V, -B, -z, -x, -v may be dropped(or change for easy
>> to remember)
>> For example:
>> -c Create a trace
>> -C Create a trace and start
>> -d Destroy trace channels
>> -D Stop and destroy trace channels
>> ...
>> or
>> -c  Create a trace
>> -cs Create a trace and start
>> -d  Destroy trace channels
>> -td Terminate and destroy trace channels
>> ...
>> But it we do, our unlucky users must read our new manual again : (
>> What is your opinion?
>>
> 
> Your patch looks great :) But I'd go directly for a command-line
> breakage so we don't end up keeping legacy options. The sooner the
> better.
> 
> I really like the -c, -C, -d, -D approach. Maybe we could have both of
> your suggestions supported as aliases ?
Hello, Mathieu

I consider about following options:

Basic options:
-c, --create tracename
	Create a trace
-d, --destroy tracename
	Destroy trace channels
-s, --start tracename
	Start tracing
-t, --terminate tracename
	Terminate tracing
-h, --help
	Show help

Advanced options:
--type
	Type of trace (ex. relay)
--ltt_root
	LTT channels root path. (ex. /mnt/debugfs/ltt)
-o, --option
	Set options, following operations are supported:
	cpu.bufnum=
	cpu.bufsize=
	cpu.overwrite=
	processes.bufnum=
	processes.bufsize=
	processes.overwrite=
	interrupts.bufnum=
	interrupts.bufsize=
	interrupts.overwrite=
	network.bufnum=
	network.bufsize=
	network.overwrite=
	modules.bufnum=
	modules.bufsize=
	modules.overwrite=
	metadata.bufnum=
	metadata.bufsize=

Integration options:
-C, --create_start tracename
        Create a trace and start
-D, --stop_destroy tracename
	Stop and destroy trace channels
-A, --all_create tracename
	All mode: Create trace, spawn a lttd daemon, start tracing.
	(optionally, you can set LTT_DAEMON env. var.)
-H, --hybrid_finish
	Stop tracing, dump flight recorder trace, destroy channels
-p, --path path
	Path for write trace datas. (ex. /root/traces/example_trace)
	For -A and -H options
-a, --append
	Append to trace
	For -A and -H options
-n, --dump_threads number
	Number of lttd threads
	For -A and -H options

For example, create and start a trace, set cpu channel's subbuf number to 4,
set network channel overwrite, and spawn a lttd daemon is:
lttctl -A trace1 -p /tmp/trace1 -o cpu.bufsize=4 -o network.overwrite=1

Option of -A(--all_create) looks some strange(not very exact), I'd like to
find a word means "Do all things for start a trace", do you have some suggestion?

And option of -H(--hybrid_finish) is not exact too, because I think we should
make it include meaning of both "finish a trace" and "hybrid", but -H only have
meaning of "hybrid".

What is your opinion about options above?
(Because my English is pool, modify of option's comment is also welcome)

> 
> If we change this, we should also update the lttv QUICKSTART file
> accordingly.
Yes, lttv also needs little update.

B.R.
Zhaolei
> 
> Mathieu
> 
>