On Fri, 03 Jun 2016, Pan Xinhui wrote:
The existing version uses a heavy barrier while only release semantics is required. So use atomic_sub_return_release instead.Suggested-by: Peter Zijlstra (Intel) <[email protected]> Signed-off-by: Pan Xinhui <[email protected]>
I just noticed this change in -tip and, while I know that saving a barrier
in core spinlock paths is perhaps a worthy exception, I cannot help but
wonder if this is the begging of the end for smp__{before,after}_atomic().
