throw("runtime.SetFinalizer: pointer not at beginning of allocated block")
		}
	}

	f := efaceOf(&finalizer)
	ftyp := f._type
	if ftyp == nil {
		// switch to system stack and remove finalizer
		systemstack(func() {
			removefinalizer(e.data)
		})
		return
	}

	if ftyp.Kind_&abi.KindMask != abi.Func {
		throw("runtime.SetFinalizer: second argument is " + toRType(ftyp).string() + ", not a function")
	}

// collection cycle.
func ReadMemStats(m *MemStats) {
	_ = m.Alloc // nil check test before we switch stacks, see issue 61158
	stw := stopTheWorld(stwReadMemStats)

	systemstack(func() {
		readmemstats_m(m)
	})

	startTheWorld(stw)
}

// doubleCheckReadMemStats controls a double-check mode for ReadMemStats that

// has completed and that there are no more writers to it.
func traceCPUFlush(gen uintptr) {
	// Flush any remaining trace buffers containing CPU samples.
	if buf := trace.cpuBuf[gen%2]; buf != nil {
		systemstack(func() {
			lock(&trace.lock)
			traceBufFlush(buf, gen)
			unlock(&trace.lock)
			trace.cpuBuf[gen%2] = nil
		})
	}
}

// traceCPUSample writes a CPU profile sample stack to the execution tracer's

// systemstack_switch is a dummy routine that systemstack leaves at the bottom
// of the G stack. We need to distinguish the routine that
// lives at the bottom of the G stack from the one that lives
// at the top of the system stack because the one at the top of
// the system stack terminates the stack walk (see topofstack()).
TEXT runtime·systemstack_switch(SB), NOSPLIT, $0-0
	RET

// func systemstack(fn func())

		// between sweep done and sweep termination (e.g. not enough
		// allocations to trigger a GC) which would be nice to fill in
		// with scavenging work.
		if debug.scavtrace > 0 {
			systemstack(func() {
				lock(&mheap_.lock)

				// Get released stats.
				releasedBg := mheap_.pages.scav.releasedBg.Load()
				releasedEager := mheap_.pages.scav.releasedEager.Load()

				// Print the line.

		pcBuf[0] = uintptr(skip)
		if getg() == gp {
			nstk += fpTracebackPCs(unsafe.Pointer(getfp()), pcBuf[1:])
		} else if gp != nil {
			// Three cases:
			//
			// (1) We're called on the g0 stack through mcall(fn) or systemstack(fn). To
			// behave like gcallers above, we start unwinding from sched.bp, which
			// points to the caller frame of the leaf frame on g's stack. The return
			// address of the leaf frame is stored in sched.pc, which we manually

	// immediately upon the next call to _lwp_park()."
	ret := lwp_unpark(int32(mp.procid), unsafe.Pointer(&mp.waitsemacount))
	if ret != 0 && ret != _ESRCH {
		// semawakeup can be called on signal stack.
		systemstack(func() {
			print("thrwakeup addr=", &mp.waitsemacount, " sem=", mp.waitsemacount, " ret=", ret, "\n")
		})
	}
}

// May run with m.p==nil, so write barriers are not allowed.
//
//go:nowritebarrier

		//
		// See the comment on enteredMarkAssistForTracing.
		enteredMarkAssistForTracing = true
	}

	// Perform assist work
	systemstack(func() {
		gcAssistAlloc1(gp, scanWork)
		// The user stack may have moved, so this can't touch
		// anything on it until it returns from systemstack.
	})

	completed := gp.param != nil
	gp.param = nil
	if completed {
		gcMarkDone()
	}

	if gp.gcAssistBytes < 0 {

	MOVDU	R3, -8(R1)
	MOVDU	R0, -8(R1)
	MOVDU	R0, -8(R1)
	MOVDU	R0, -8(R1)
	MOVDU	R0, -8(R1)
	BL	(CTR)
	MOVD	24(R1), R2
	BR	runtime·badmcall2(SB)

// systemstack_switch is a dummy routine that systemstack leaves at the bottom
// of the G stack. We need to distinguish the routine that
// lives at the bottom of the G stack from the one that lives
// at the top of the system stack because the one at the top of

	RET

// systemstack_switch is a dummy routine that systemstack leaves at the bottom
// of the G stack. We need to distinguish the routine that
// lives at the bottom of the G stack from the one that lives
// at the top of the system stack because the one at the top of
// the system stack terminates the stack walk (see topofstack()).
// The frame layout needs to match systemstack
// so that it can pretend to be systemstack_switch.