On 09/08/2016 11:19 AM, Peter Zijlstra wrote:

On Thu, Sep 08, 2016 at 09:28:18AM -0700, Vineet Gupta wrote:

quoted

This came to light when implementing native 64-bit atomics for ARCv2.

The atomic64 self-test code uses CONFIG_ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
to check whether atomic64_dec_if_positive() is available.
It seems it was needed when not every arch defined it.
However as of current code the Kconfig option seems needless

- for CONFIG_GENERIC_ATOMIC64 it is auto-enabled in lib/Kconfig and a
  generic definition of API is present lib/atomic64.c
- arches with native 64-bit atomics select it in arch/*/Kconfig and
  define the API in their headers

So I see no point in keeping the Kconfig option

Compile tested for 2 representatives:
 - blackfin (CONFIG_GENERIC_ATOMIC64)
 - x86 (!CONFIG_GENERIC_ATOMIC64)

Also logistics wise it seemed simpler to just do this in 1 patch vs.
splitting per arch - but I can break it up if maintainer feel that
is better to avoid conflicts.

Works for me; you want me to take this, or do you need it for you ARCv2
patches?

Please do. ARCv2 patch (following shortly) doesn't need it - I selected the
option in orig patch - which I can just take out.

Thx,
-Vineet