This was OKd but forgotten: http://openbsd-archive.7691.n7.nabble.com/remove-MPSAFE-from-makesyscalls-sh-td293382.html
Index: sys/sys/systm.h =================================================================== RCS file: /cvs/src/sys/sys/systm.h,v retrieving revision 1.113 diff -u -p -r1.113 systm.h --- sys/sys/systm.h 17 May 2016 23:28:03 -0000 1.113 +++ sys/sys/systm.h 1 Sep 2016 07:34:19 -0000 @@ -112,8 +112,7 @@ extern struct sysent { /* system call t sy_call_t *sy_call; /* implementing function */ } sysent[]; -#define SY_MPSAFE 0x01 -#define SY_NOLOCK 0x02 +#define SY_NOLOCK 0x01 #if _BYTE_ORDER == _BIG_ENDIAN #define SCARG(p, k) ((p)->k.be.datum) /* get arg from args pointer */ Index: sys/kern/makesyscalls.sh =================================================================== RCS file: /cvs/src/sys/kern/makesyscalls.sh,v retrieving revision 1.11 diff -u -p -r1.11 makesyscalls.sh --- sys/kern/makesyscalls.sh 27 Nov 2007 18:04:01 -0000 1.11 +++ sys/kern/makesyscalls.sh 1 Sep 2016 07:34:19 -0000 @@ -255,10 +255,6 @@ function parseline() { funcalias="" end=NF } - if ($f == "MPSAFE") { # allow MP-safe syscalls - sycall_flags = sprintf("SY_MPSAFE | %s", sycall_flags) - f++ - } if ($f == "NOLOCK") { # syscall does not need locks sycall_flags = sprintf("SY_NOLOCK | %s", sycall_flags) f++ -- Michal Mazurek