Subject: Re: linux-next: percpu/tip tree build failure

From: Tejun Heo <[email-masked]>
Date: Tue, 08 Dec 2009 17:37:50 +0900

Hello,

On 12/08/2009 05:24 PM, Ingo Molnar wrote:
>> Acked-by: Frederic Weisbecker <[email-masked]>
> 
> I have applied it - but really, the new percpu namespace changes headed 
> towards upstream are quite a nuisance IMO. The 3-4 (trivial to solve) 
> breakages i've seen so far affecting code i maintain give us an 
> estimation about the ongoing maintainence cost - which wont be high but 
> not zero either.
> 
> The change that was forced here:
> 
>  -static DEFINE_PER_CPU(unsigned int, task_bp_pinned[HBP_NUM]);
>  +static DEFINE_PER_CPU(unsigned int, nr_task_bp_pinned[HBP_NUM]);
> 
> Is it really an improvement to the old code?
>
> Dunno.

In each specific conflict, I don't think it would be an apparent
improvement but overall I do believe it's headed the right way.  Well,
or, at the very least, I don't see any other viable solution and
you're probably the most strongly affected by the change.  Sorry about
the inconveniences.

I'm waiting for ack for a m68k change before pushing out percpu tree.
I'm not completely determined but I think I'll keep dropping per_cpu__
prefix and sparse annotation in linux-next for one more cycle as
sparse annotation cleanup pass hasn't been done yet.  Once new devel
cycle begins, it might be a good idea to pull in percpu changes into
one of the tip trees so that these nuisances can be detected during
development?

Thanks.

-- 
tejun