diff --git a/unix/syscall_openbsd.go b/unix/syscall_openbsd.go
index 07e6669..2c674a5 100644
--- a/unix/syscall_openbsd.go
+++ b/unix/syscall_openbsd.go
@@ -43,6 +43,23 @@
 	return nil, EINVAL
 }
 
+func SysctlUvmexp(name string) (*Uvmexp, error) {
+	mib, err := sysctlmib(name)
+	if err != nil {
+		return nil, err
+	}
+
+	n := uintptr(SizeofUvmexp)
+	var u Uvmexp
+	if err := sysctl(mib, (*byte)(unsafe.Pointer(&u)), &n, nil, 0); err != nil {
+		return nil, err
+	}
+	if n != SizeofUvmexp {
+		return nil, EIO
+	}
+	return &u, nil
+}
+
 //sysnb pipe(p *[2]_C_int) (err error)
 func Pipe(p []int) (err error) {
 	if len(p) != 2 {
diff --git a/unix/syscall_openbsd_test.go b/unix/syscall_openbsd_test.go
new file mode 100644
index 0000000..65ad1d1
--- /dev/null
+++ b/unix/syscall_openbsd_test.go
@@ -0,0 +1,19 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package unix_test
+
+import (
+	"testing"
+
+	"golang.org/x/sys/unix"
+)
+
+func TestSysctlUvmexp(t *testing.T) {
+	uvm, err := unix.SysctlUvmexp("vm.uvmexp")
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Logf("free = %v", uvm.Free)
+}
diff --git a/unix/types_openbsd.go b/unix/types_openbsd.go
index 8f2fe70..ff45481 100644
--- a/unix/types_openbsd.go
+++ b/unix/types_openbsd.go
@@ -38,6 +38,7 @@
 #include <sys/un.h>
 #include <sys/utsname.h>
 #include <sys/wait.h>
+#include <uvm/uvmexp.h>
 #include <net/bpf.h>
 #include <net/if.h>
 #include <net/if_dl.h>
@@ -263,3 +264,9 @@
 // Uname
 
 type Utsname C.struct_utsname
+
+// Uvmexp
+
+const SizeofUvmexp = C.sizeof_struct_uvmexp
+
+type Uvmexp C.struct_uvmexp
diff --git a/unix/zerrors_openbsd_amd64.go b/unix/zerrors_openbsd_amd64.go
index 12261a5..1f9e8a2 100644
--- a/unix/zerrors_openbsd_amd64.go
+++ b/unix/zerrors_openbsd_amd64.go
@@ -952,6 +952,7 @@
 	MNT_NOATIME                       = 0x8000
 	MNT_NODEV                         = 0x10
 	MNT_NOEXEC                        = 0x4
+	MNT_NOPERM                        = 0x20
 	MNT_NOSUID                        = 0x8
 	MNT_NOWAIT                        = 0x2
 	MNT_QUOTA                         = 0x2000
@@ -959,6 +960,7 @@
 	MNT_RELOAD                        = 0x40000
 	MNT_ROOTFS                        = 0x4000
 	MNT_SOFTDEP                       = 0x4000000
+	MNT_STALLED                       = 0x100000
 	MNT_SYNCHRONOUS                   = 0x2
 	MNT_UPDATE                        = 0x10000
 	MNT_VISFLAGMASK                   = 0x400ffff
@@ -1441,6 +1443,8 @@
 	TIOCUCNTL_CBRK                    = 0x7a
 	TIOCUCNTL_SBRK                    = 0x7b
 	TOSTOP                            = 0x400000
+	UTIME_NOW                         = -0x2
+	UTIME_OMIT                        = -0x1
 	VDISCARD                          = 0xf
 	VDSUSP                            = 0xb
 	VEOF                              = 0x0
diff --git a/unix/ztypes_openbsd_386.go b/unix/ztypes_openbsd_386.go
index 231f4e8..412db97 100644
--- a/unix/ztypes_openbsd_386.go
+++ b/unix/ztypes_openbsd_386.go
@@ -465,3 +465,94 @@
 	Version  [256]byte
 	Machine  [256]byte
 }
+
+const SizeofUvmexp = 0x158
+
+type Uvmexp struct {
+	Pagesize           int32
+	Pagemask           int32
+	Pageshift          int32
+	Npages             int32
+	Free               int32
+	Active             int32
+	Inactive           int32
+	Paging             int32
+	Wired              int32
+	Zeropages          int32
+	Reserve_pagedaemon int32
+	Reserve_kernel     int32
+	Anonpages          int32
+	Vnodepages         int32
+	Vtextpages         int32
+	Freemin            int32
+	Freetarg           int32
+	Inactarg           int32
+	Wiredmax           int32
+	Anonmin            int32
+	Vtextmin           int32
+	Vnodemin           int32
+	Anonminpct         int32
+	Vtextminpct        int32
+	Vnodeminpct        int32
+	Nswapdev           int32
+	Swpages            int32
+	Swpginuse          int32
+	Swpgonly           int32
+	Nswget             int32
+	Nanon              int32
+	Nanonneeded        int32
+	Nfreeanon          int32
+	Faults             int32
+	Traps              int32
+	Intrs              int32
+	Swtch              int32
+	Softs              int32
+	Syscalls           int32
+	Pageins            int32
+	Obsolete_swapins   int32
+	Obsolete_swapouts  int32
+	Pgswapin           int32
+	Pgswapout          int32
+	Forks              int32
+	Forks_ppwait       int32
+	Forks_sharevm      int32
+	Pga_zerohit        int32
+	Pga_zeromiss       int32
+	Zeroaborts         int32
+	Fltnoram           int32
+	Fltnoanon          int32
+	Fltnoamap          int32
+	Fltpgwait          int32
+	Fltpgrele          int32
+	Fltrelck           int32
+	Fltrelckok         int32
+	Fltanget           int32
+	Fltanretry         int32
+	Fltamcopy          int32
+	Fltnamap           int32
+	Fltnomap           int32
+	Fltlget            int32
+	Fltget             int32
+	Flt_anon           int32
+	Flt_acow           int32
+	Flt_obj            int32
+	Flt_prcopy         int32
+	Flt_przero         int32
+	Pdwoke             int32
+	Pdrevs             int32
+	Pdswout            int32
+	Pdfreed            int32
+	Pdscans            int32
+	Pdanscan           int32
+	Pdobscan           int32
+	Pdreact            int32
+	Pdbusy             int32
+	Pdpageouts         int32
+	Pdpending          int32
+	Pddeact            int32
+	Pdreanon           int32
+	Pdrevnode          int32
+	Pdrevtext          int32
+	Fpswtch            int32
+	Kmapent            int32
+}
diff --git a/unix/ztypes_openbsd_amd64.go b/unix/ztypes_openbsd_amd64.go
index bb2c448..c45df92 100644
--- a/unix/ztypes_openbsd_amd64.go
+++ b/unix/ztypes_openbsd_amd64.go
@@ -465,3 +465,94 @@
 	Version  [256]byte
 	Machine  [256]byte
 }
+
+const SizeofUvmexp = 0x158
+
+type Uvmexp struct {
+	Pagesize           int32
+	Pagemask           int32
+	Pageshift          int32
+	Npages             int32
+	Free               int32
+	Active             int32
+	Inactive           int32
+	Paging             int32
+	Wired              int32
+	Zeropages          int32
+	Reserve_pagedaemon int32
+	Reserve_kernel     int32
+	Anonpages          int32
+	Vnodepages         int32
+	Vtextpages         int32
+	Freemin            int32
+	Freetarg           int32
+	Inactarg           int32
+	Wiredmax           int32
+	Anonmin            int32
+	Vtextmin           int32
+	Vnodemin           int32
+	Anonminpct         int32
+	Vtextminpct        int32
+	Vnodeminpct        int32
+	Nswapdev           int32
+	Swpages            int32
+	Swpginuse          int32
+	Swpgonly           int32
+	Nswget             int32
+	Nanon              int32
+	Nanonneeded        int32
+	Nfreeanon          int32
+	Faults             int32
+	Traps              int32
+	Intrs              int32
+	Swtch              int32
+	Softs              int32
+	Syscalls           int32
+	Pageins            int32
+	Obsolete_swapins   int32
+	Obsolete_swapouts  int32
+	Pgswapin           int32
+	Pgswapout          int32
+	Forks              int32
+	Forks_ppwait       int32
+	Forks_sharevm      int32
+	Pga_zerohit        int32
+	Pga_zeromiss       int32
+	Zeroaborts         int32
+	Fltnoram           int32
+	Fltnoanon          int32
+	Fltnoamap          int32
+	Fltpgwait          int32
+	Fltpgrele          int32
+	Fltrelck           int32
+	Fltrelckok         int32
+	Fltanget           int32
+	Fltanretry         int32
+	Fltamcopy          int32
+	Fltnamap           int32
+	Fltnomap           int32
+	Fltlget            int32
+	Fltget             int32
+	Flt_anon           int32
+	Flt_acow           int32
+	Flt_obj            int32
+	Flt_prcopy         int32
+	Flt_przero         int32
+	Pdwoke             int32
+	Pdrevs             int32
+	Pdswout            int32
+	Pdfreed            int32
+	Pdscans            int32
+	Pdanscan           int32
+	Pdobscan           int32
+	Pdreact            int32
+	Pdbusy             int32
+	Pdpageouts         int32
+	Pdpending          int32
+	Pddeact            int32
+	Pdreanon           int32
+	Pdrevnode          int32
+	Pdrevtext          int32
+	Fpswtch            int32
+	Kmapent            int32
+}
diff --git a/unix/ztypes_openbsd_arm.go b/unix/ztypes_openbsd_arm.go
index 941367c..927bf10 100644
--- a/unix/ztypes_openbsd_arm.go
+++ b/unix/ztypes_openbsd_arm.go
@@ -458,3 +458,94 @@
 	Version  [256]byte
 	Machine  [256]byte
 }
+
+const SizeofUvmexp = 0x158
+
+type Uvmexp struct {
+	Pagesize           int32
+	Pagemask           int32
+	Pageshift          int32
+	Npages             int32
+	Free               int32
+	Active             int32
+	Inactive           int32
+	Paging             int32
+	Wired              int32
+	Zeropages          int32
+	Reserve_pagedaemon int32
+	Reserve_kernel     int32
+	Anonpages          int32
+	Vnodepages         int32
+	Vtextpages         int32
+	Freemin            int32
+	Freetarg           int32
+	Inactarg           int32
+	Wiredmax           int32
+	Anonmin            int32
+	Vtextmin           int32
+	Vnodemin           int32
+	Anonminpct         int32
+	Vtextminpct        int32
+	Vnodeminpct        int32
+	Nswapdev           int32
+	Swpages            int32
+	Swpginuse          int32
+	Swpgonly           int32
+	Nswget             int32
+	Nanon              int32
+	Nanonneeded        int32
+	Nfreeanon          int32
+	Faults             int32
+	Traps              int32
+	Intrs              int32
+	Swtch              int32
+	Softs              int32
+	Syscalls           int32
+	Pageins            int32
+	Obsolete_swapins   int32
+	Obsolete_swapouts  int32
+	Pgswapin           int32
+	Pgswapout          int32
+	Forks              int32
+	Forks_ppwait       int32
+	Forks_sharevm      int32
+	Pga_zerohit        int32
+	Pga_zeromiss       int32
+	Zeroaborts         int32
+	Fltnoram           int32
+	Fltnoanon          int32
+	Fltnoamap          int32
+	Fltpgwait          int32
+	Fltpgrele          int32
+	Fltrelck           int32
+	Fltrelckok         int32
+	Fltanget           int32
+	Fltanretry         int32
+	Fltamcopy          int32
+	Fltnamap           int32
+	Fltnomap           int32
+	Fltlget            int32
+	Fltget             int32
+	Flt_anon           int32
+	Flt_acow           int32
+	Flt_obj            int32
+	Flt_prcopy         int32
+	Flt_przero         int32
+	Pdwoke             int32
+	Pdrevs             int32
+	Pdswout            int32
+	Pdfreed            int32
+	Pdscans            int32
+	Pdanscan           int32
+	Pdobscan           int32
+	Pdreact            int32
+	Pdbusy             int32
+	Pdpageouts         int32
+	Pdpending          int32
+	Pddeact            int32
+	Pdreanon           int32
+	Pdrevnode          int32
+	Pdrevtext          int32
+	Fpswtch            int32
+	Kmapent            int32
+}