Re: [RFC] [Patch 4/4] lock contention tracking slimmed down

[Martin Peschke <mp3@de.ibm.com>]

Ingo Molnar wrote:
> if the infrastructure your are advocating does not allow us to keep the 
> existing output then it's simply not flexible enough.

Let's be precise. If "keep the existing output" means any format change is
unacceptible to you, then I broke things. If it means that my method provides
data equivalent in respect of content, then I didn't break the lock contention
output.

> Why on earth are you even arguing about this?
 > A "cleanup" should not change the output, simple as that.
 > Do a patch that has the _same_ output and then we can
> see whether it's a good patch. You made the same mistake with your 
> /proc/timer_stats cleanups.

We got to be careful here. My other proposal was doomed because timerstat became 
kernel ABI in the meantime. We won't break the kernel ABI. I was late, as simple 
as that.

The lock contention stuff isn't kernel ABI yet. This is -mm code, stuff
intented for a wider audience and discussion. It should be perfectly fine
to scrutinize kernel ABI additions before we get beyond the point of no return.

> I dont like NACK-ing patches but you seem to 
> be missing the basic precondition of cleanups: no functional effect to 
> the code, and certainly no change in output.

I don't see the point of judging something by goals that have not been set.
I have advertised my patches as: same purpose, different or generalised method,
differences in output format, output equivalent in respect of content,
much more code sharing.

Martin