This chunk has been #ifdef since r1.1 in 1995. I'd like to revisit SB_LOCK so this is in my way. Ok to remove it?
Index: kern/uipc_usrreq.c =================================================================== RCS file: /cvs/src/sys/kern/uipc_usrreq.c,v retrieving revision 1.120 diff -u -p -r1.120 uipc_usrreq.c --- kern/uipc_usrreq.c 2 Nov 2017 14:01:18 -0000 1.120 +++ kern/uipc_usrreq.c 11 Dec 2017 07:57:48 -0000 @@ -963,22 +963,6 @@ unp_gc(void *arg __unused) unp->unp_flags |= UNP_GCMARK; so = unp->unp_socket; -#ifdef notdef - if (so->so_rcv.sb_flags & SB_LOCK) { - /* - * This is problematical; it's not clear - * we need to wait for the sockbuf to be - * unlocked (on a uniprocessor, at least), - * and it's also not clear what to do - * if sbwait returns an error due to receipt - * of a signal. If sbwait does return - * an error, we'll go into an infinite - * loop. Delete all of this for now. - */ - (void) sbwait(&so->so_rcv); - goto restart; - } -#endif unp_scan(so->so_rcv.sb_mb, unp_mark); } } while (unp_defer);