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

From: Ingo Molnar
Date: Tue Aug 25 2009 - 18:03:48 EST



* Theodore Tso <tytso@xxxxxxx> 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
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