Unified tracing buffer

[Martin Bligh]

>> I think the main reason of using single-channel mode is simplicity of
>> userspace reader. We can use 'cat' or 'tail' to read the buffer on-line.
>> I'm not sure how much overhead ftrace-like buffer merging routine has,
>> but if kernel provides an interface which gives us single-merged buffer
>> image(like ftrace buffer), we are grad to use it. :-)
>
> Yup, I also think it is better.

That was the plan, yes. Merge sort is cheap ;-)