Re: cvs commit: src/include string.h src/lib/libc/string Makefile.inc memchr.3 memrchr.c src/sys/sys param.h

From: Robert Watson <rwatson_at_FreeBSD.org>
Date: Thu, 29 May 2008 08:50:24 +0100 (BST)
On Wed, 28 May 2008, Daniel Eischen wrote:

> There's nothing technically wrong with it in that it will work, but for 
> minor features that provide low marginal utility, I'm not sure that it is 
> warranted.  I would rather see the bar raised for new features added to 
> -stable branches.  But I don't feel strongly enough one way or the other to 
> request a backout.

I think there's actually a strong contrary argument to this in the general 
case: the things we should try hardest to MFC are the most trivial changes, as 
those changes have the lowest risk and highest utility in reducing gratuitous 
differences between branches.  The more "minor" changes present in HEAD vs a 
RELENG_ branch, the harder it is to merge larger functional changes: there may 
be conflicting diffs, subtle dependencies, etc.

I don't have any specific cases in mind for this particular function, but 
certainly in the network stack and elsewhere in the kernel, there is a strong 
motivation to merge quickly and frequently for minor changes so that they 
don't build up over time and make other, more important, changes harder to 
merge.  The more we allow 8.x and 7.x to diverge, the harder it will be to 
bring back changes and keep the 7.x branch running in the long term, and the 
more likely it is that when we run into harder merges later.

So, this is neither a vote for nor against a backout, but this is a general 
call to resist the conservative tendancy that says "don't MFC minor things" 
because, in macro, it has a significant drag effect on the MFC process that 
keeps RELENG branches maintainable.

Robert N M Watson
Computer Laboratory
University of Cambridge
Received on Thu May 29 2008 - 07:50:25 UTC