Re: [PATCH 7/8] percpu: add __percpu sparse annotations to hw_breakpoint

Frederic Weisbecker
2010-01-26T00:19:14Z

On Tue, Jan 26, 2010 at 12:22:14AM +0900, Tejun Heo wrote:
> Add __percpu sparse annotations to hw_breakpoint.
>
> These annotations are to make sparse consider percpu variables to be
> in a different address space and warn if accessed without going
> through percpu accessors. This patch doesn't affect normal builds.
>
> per_cpu(nr_task_bp_pinned, cpu) is replaced with
> &per_cpu(nr_task_bp_pinned[0], cpu). This is the same to the compiler
> but allows per_cpu() macro to correctly drop __percpu designation for
> the returned pointer.

Ouch... It's unpleasant to see such workaround that messes up the
code just to make sparse happy.

I guess __percpu is an address_space attribute? Is there no
way to force the address space change directly from the
per_cpu() macro?

Thanks.