setting tunables in stable/10 vs head?

Hi,

I just MFC'd a patch from head to stable/10 that defines some
tunables using CTLFLAG_RDTUN. Although the MFC didn't break
anything, the tunables don't get changed by the values in /boot/loader.conf.

By applying a patch like this:
 SYSCTL_DECL(_vfs_nfsd);
 int	nfsrv_statehashsize = NFSSTATEHASHSIZE;
+TUNABLE_INT("vfs.nfsd.statehashsize", &nfsrv_statehashsize);
 SYSCTL_INT(_vfs_nfsd, OID_AUTO, statehashsize, CTLFLAG_RDTUN,
     &nfsrv_statehashsize, 0,
     "Size of state hash table set via loader.conf");

they get set ok.

So, is this correct or have I done something stupid?

And, if it correct, do I commit a patch like the above directly
to stable/10. (It seems that TUNABLE_INT() is discouraged for -head.)

Thanks for any help with this, rick