f7db0c9532
This is mostly mechanical except for vmspace_exit(). There, use the new refcount_release_if_last() to avoid switching to vmspace0 unless other processes are sharing the vmspace. In that case, upon switching to vmspace0 we can unconditionally release the reference. Remove the volatile qualifier from vm_refcnt now that accesses are protected using refcount(9) KPIs. Reviewed by: alc, kib, mmel MFC after: 1 month Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D27057