Re: [tip:timers/core] timekeeping: Increase granularity of read_persistent_clock()

[Ingo Molnar <mingo@elte.hu>]

* Theodore Tso <tytso@mit.edu> wrote:

> On Tue, Aug 25, 2009 at 03:50:17PM +0200, Ingo Molnar wrote:
> > > [...]  It's like making changes inside #ifdef CONFIG_FOO but never 
> > > testing with CONFIG_FOO turned on.  You'd complain, and rightly, 
> > > if someone did that.
> > 
> > You again seem to ignore the very valid case i pointed out: if i 
> > change generic code (or an include, an inline function or a 
> > define) which somehow affects an architecture, by your logic i'd 
> > be compelled to test it on that architecture - because it 
> > affects it. That's not reasonable overhead.
> 
> Paul, Ingo, it seems like the two of you are talking past each 
> other. He's said he's OK with generic code which somehow affects 
> an architecture only being tested on one architecture, so what 
> you're proposing is a straw man.  What he has requested it would 
> be nice that each line of code be compile-tested on at least *one* 
> architecture. If it's generic code, then by definition when you 
> compile on x86, it's met the criterion he has proposed.
> 
> On the other hand, your claim that it would slow down development 
> too much is based on the assumption that if you make a change in 
> generic code that breaks architecture-specific code, it's good 
> manners to at least *attempt* to fix up the architecture-specific 
> code, as opposed to leaving it broken. [...]

That's (of course!) what happened here.

In fact, more than just an attempt happened, the thread started by 
_me_ finding this build breakage to begin with:

> > > FYI, -tip arch-testing found that this commit broke the PowerPC 
> > > build:
> > > 
> > > /home/mingo/tip/arch/powerpc/kernel/time.c: In function 'read_persistent_clock':
> > > /home/mingo/tip/arch/powerpc/kernel/time.c:788: error: 'return' with a value, in function returning void

and i applied the fix from Martin very quickly as well.

So i think this is much ado about nothing. Testing was done, the fix 
was applied immediately and no kitten was hurt in the process.

	Ingo