Re: [PATCH] Native spinlock support on RISC-V

"Andres Freund" <andres(at)anarazel(dot)de> writes:
> On Fri, Aug 13, 2021, at 19:25, Tom Lane wrote:
>> I now have looked at the patch, and it seems good as far as it goes,
>> but I wonder whether some effort ought to be expended in
>> src/include/port/atomics/.

> That should automatically pick up the intrinsic. I think we should do the same on modern compilers for spinlocks, but that's a separate discussion I guess.

I was looking at the comment in atomics.h about

* Provide a full fallback of the pg_*_barrier(), pg_atomic**_flag and
* pg_atomic_* APIs for platforms without sufficient spinlock and/or atomics
* support. In the case of spinlock backed atomics the emulation is expected
* to be efficient, although less so than native atomics support.

so it seems like someday we might want to expend some effort on native
atomics. I agree that that day need not be today, though. This patch
seems sufficient until we get to the point of (at least) having some
RISC-V in the buildfarm.

regards, tom lane