Hi,
On 2017-02-03 20:01:03 +0300, Alexander Korotkov wrote:
> Using assembly in lwlock.c looks rough. This is why I refactored it by
> introducing new atomic operation pg_atomic_fetch_mask_add_u32 (see
> lwlock-power-2.patch). It checks that all masked bits are clear and then
> adds to variable. This atomic have special assembly implementation for
> Power, and generic implementation for other platforms with loop of CAS.
> Probably we would have other implementations for other architectures in
> future. This level of abstraction is the best I managed to invent.
I think that's a reasonable approach. And I think it might be worth
experimenting with a more efficient implementation on x86 too, using
hardware lock elision / HLE and/or tsx.
Andres
