Re: [PATCH v3 01/11] counters: Introduce counter_atomic* counters

From: Peter Zijlstra
Date: Fri Oct 09 2020 - 15:49:11 EST


On Fri, Oct 09, 2020 at 09:55:56AM -0600, Shuah Khan wrote:
> Introduce Simple atomic counters.
>
> There are a number of atomic_t usages in the kernel where atomic_t api
> is used strictly for counting and not for managing object lifetime. In
> some cases, atomic_t might not even be needed.
>
> The purpose of these counters is to clearly differentiate atomic_t
> counters from atomic_t usages that guard object lifetimes, hence prone
> to overflow and underflow errors. It allows tools that scan for underflow
> and overflow on atomic_t usages to detect overflow and underflows to scan
> just the cases that are prone to errors.

Under- and overflow on atomic_t is perfectly fine. We're not going to
create pointless wrappers for this.

What tools, and how could they not be served by adding annotations to
variable declarations?