From mboxrd@z Thu Jan  1 00:00:00 1970
From: zhaolei@cn.fujitsu.com (Zhaolei)
Date: Mon, 20 Oct 2008 11:03:53 +0800
Subject: [ltt-dev] TODO list before releasing LTTng-buffering to LKML]
References: <48F733E6.9010007@cn.fujitsu.com> <48F80CDD.2070205@cn.fujitsu.com>
	<20081017042045.GB5067@Krystal>
	<FC4CA1D695704A0FABBD56B07C048B13@zhaoleiwin>
	<20081017161429.GA5696@Krystal>
Message-ID: <A89E56E045314381B5ACD7622208ED81@zhaoleiwin>

Hello, Mathieu.

>> Are you means we can control each channel's (interrupt, process, ...) subbuf in future version?
>> (I think current version can only control low, med and high)
>> If this is true, maybe we need modify ltt_trace_create() before impl ltt_control.
>> 
> Yes, this is the goal.
So, IMHO, we can do it in following steps:

Step1: modify ltt_trace_create(), .etc, separate ltt_trace_create() into
  ltt_trace_setup(), ltt_set_channelsize(), ltt_set_channelnum(),
  ltt_trace_alloc(). But still use old netlink_based ltt_control to make
  it simple. 
  Although we modify ltt_set_channelsize() to support setting each channel's
  buffer, we make ltt_control.ko using old UI(only able to set low, med and
  high). So we don't need to modify other program such as user-mode lttctl.

Step2: Write a new module named ltt-channel-control.
  ( I think name of ltt-channel-control will be better than ltt-control,
    because we already have a module named ltt-marker-control. )
  ltt-channel-control is designed on debugfs, as we discussed.
  We can test it by echo XX > /mnt/debugfs/ltt/...

Step3: modify user-mode programs to support ltt-channel-control.
  We also need to modify lttctl's command arguments, to support setup each
  channel's buffer. (Are we take out -Z, -X, -V, -B, -z, -x in lttctl?)
  I haven't read source of lttv, it is necessary to modify?

B.R.
Zhaolei