Re: [PATCH] x86: fix init_memory_mapping for [dc000000 - e0000000)

[Ingo Molnar <mingo@elte.hu>]

* Cyrill Gorcunov <gorcunov@gmail.com> wrote:

> [Ingo Molnar - Tue, Oct 28, 2008 at 10:27:37AM +0100]
> | 
> | * Yinghai Lu <yinghai@kernel.org> wrote:
> | 
> | > Impact: fix range calculation
> | 
> | applied to tip/x86/urgent, thanks Yinghai!
> | 
> | i changed the impact line to:
> | 
> | Impact: change over-mapping to precise mapping, fix /proc/meminfo output
> | 
> | 	Ingo
> | 
> 
> When we started to use Impact: line? I mean -- now we have
> to use it? Just noticed this word in patches a day or maybe
> several day ago -- so it seem to be quite freshy :)

We've been experimenting with the impact-line for a couple of 
weeks/months, just to see how it works out in practice.

The first impact-line ever was added by hpa in mid-summer:

| commit 908ec7afacfdc83dc10938ed1d3c38b3526034ec
| Author: H. Peter Anvin <hpa@zytor.com>
| Date:   Mon Jun 30 14:42:18 2008 -0700
|
|    x86: remove arbitrary ELF section limit in i386 relocatable kernel
|    
|    Impact: build failure in maximal configurations

The concept seems to be quite good in general:

 - increases the readability of the changlogs

 - makes it easier to judge the backporting needs of a commit, even 
   if a commit has not been marked as Cc: <stable@kernel.org> straight 
   away.

 - makes it easier to notice bugs in a commit: when a commit marked as 
   "Impact: cleanup" causes some behavioral change it's clear that 
   it's buggy.

It basically acts as a second-level subject line.

So, given these many advantages, we now try to extend the use of 
impact-lines to all the tip/*/urgent branches.

It's not a must-have item for patch submissions, just a nice-to-have 
property. (we'll add the impact-line when it's missing)

	Ingo