Introduce atomic_load() and atomic_store().

[kib]

Summary

This is the discussed patch with ops renamed (_relaxed removed). The documentation was stripped as well, the operations are explained in D13522.

[alc]

sys/vm/uma_core.c

3173 ↗

(On Diff #36715)

I would suggest using atomic_load() here so that all accesses to this variable are made with explicit atomics. Or else, don't use atomic_store() below. In other words, I don't see an argument for using store below but not using load here.

[alc]

I'm happy with the implementation. (I assume that the use cases will be committed separately.)

[kib]

Make all accesses to uma_reclaim_needed use atomic(9) KPI.

[alc]

sys/vm/uma_core.c

3173 ↗

(On Diff #36717)

atomic_load_int?

[jhb]

With the caveat of fixing the atomic_load -> atomic_load_int alc@ already noted. Thanks for doing this.