func (p *cpuProfile) add(tagPtr *unsafe.Pointer, stk []uintptr) {
	// Simple cas-lock to coordinate with setcpuprofilerate.
	for !prof.signalLock.CompareAndSwap(0, 1) {
		// TODO: Is it safe to osyield here? https://go.dev/issue/52672
		osyield()
	}

	if prof.hz.Load() != 0 { // implies cpuprof.log != nil
		if p.numExtra > 0 || p.lostExtra > 0 || p.lostAtomic > 0 {
			p.addExtra()
		}
		hdr := [1]uint64{1}

		netpollBroken = false
		unlock(&netpollBrokenLock)

		notetsleep(&netpollNote, delay)
		unlock(&netpollStubLock)
		// Guard against starvation in case the lock is contended
		// (eg when running TestNetpollBreak).
		osyield()
	}
	return gList{}, 0
}

func netpollinited() bool {
	return netpollInited.Load() != 0
}

func netpollAnyWaiters() bool {
	return false
}

func netpollAdjustWaiters(delta int32) {

func lwp_kill(pid, tid int32, sig int)

//go:noescape
func sys_umtx_sleep(addr *uint32, val, timeout int32) int32

//go:noescape
func sys_umtx_wakeup(addr *uint32, val int32) int32

func osyield()

//go:nosplit
func osyield_no_g() {
	osyield()
}

func kqueue() int32

//go:noescape
func kevent(kq int32, ch *keventt, nch int32, ev *keventt, nev int32, ts *timespec) int32

func pipe2(flags int32) (r, w int32, errno int32)

	}
	if gp != nil {
		hdr[1] = gp.goid
	}
	hdr[2] = uint64(mp.procid)

	// Allow only one writer at a time
	for !trace.signalLock.CompareAndSwap(0, 1) {
		// TODO: Is it safe to osyield here? https://go.dev/issue/52672
		osyield()
	}

	if log := trace.cpuLogWrite[gen%2].Load(); log != nil {
		// Note: we don't pass a tag pointer here (how should profiling tags

//go:noescape
func lwp_unpark(lwp int32, hint unsafe.Pointer) int32

func lwp_self() int32

func osyield()

//go:nosplit
func osyield_no_g() {
	osyield()
}

func kqueue() int32

//go:noescape
func kevent(kq int32, ch *keventt, nch int32, ev *keventt, nev int32, ts *timespec) int32

func pipe2(flags int32) (r, w int32, errno int32)

	return 0
}

func initsig(preinit bool) {
	if !preinit {
		notify(unsafe.Pointer(abi.FuncPCABI0(sigtramp)))
	}
}

//go:nosplit
func osyield() {
	sleep(0)
}

//go:nosplit
func osyield_no_g() {
	osyield()
}

//go:nosplit
func usleep(µs uint32) {
	ms := int32(µs / 1000)
	if ms == 0 {
		ms = 1
	}
	sleep(ms)
}

//go:nosplit

func thr_self() thread
func thr_kill(tid thread, sig int)

//go:noescape
func sys_umtx_op(addr *uint32, mode int32, val uint32, uaddr1 uintptr, ut *umtx_time) int32

func osyield()

//go:nosplit
func osyield_no_g() {
	osyield()
}

func kqueue() int32

//go:noescape
func kevent(kq int32, ch *keventt, nch int32, ev *keventt, nev int32, ts *timespec) int32

func pipe2(flags int32) (r, w int32, errno int32)

}

func osyield1()

//go:nosplit
func osyield_no_g() {
	osyield1()
}

//go:nosplit
func osyield() {
	r, err := syscall0(&libc_sched_yield)
	if int32(r) == -1 {
		println("syscall osyield failed: ", hex(err))
		throw("syscall osyield")
	}
}

//go:nosplit
func sysconf(name int32) uintptr {
	r, _ := syscall1(&libc_sysconf, uintptr(name))
	if int32(r) == -1 {

		// Try for lock, rescheduling.
		for i := 0; i < passive_spin; i++ {
			for l.key == mutex_unlocked {
				if atomic.Cas(key32(&l.key), mutex_unlocked, wait) {
					timer.end()
					return
				}
			}
			osyield()
		}

		// Sleep.
		v = atomic.Xchg(key32(&l.key), mutex_sleeping)
		if v == mutex_unlocked {
			timer.end()
			return
		}
		wait = mutex_sleeping
		futexsleep(key32(&l.key), mutex_sleeping, -1)

	// have been delivered. Give other threads a chance to run and
	// pick up the signal.
	osyield()
	osyield()
	osyield()

	// If that didn't work, try _SIG_DFL.
	setsig(sig, _SIG_DFL)
	raise(sig)

	osyield()
	osyield()
	osyield()

	// If we are still somehow running, just exit with the wrong status.
	exit(2)
}