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) <pet...@infradead.org>
Signed-off-by: Pan Xinhui <xinhui....@linux.vnet.ibm.com>
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().
