type traceLocker struct {
	mp  *m
	gen uintptr
}

// debugTraceReentrancy checks if the trace is reentrant.
//
// This is optional because throwing in a function makes it instantly
// not inlineable, and we want traceAcquire to be inlineable for
// low overhead when the trace is disabled.
const debugTraceReentrancy = false

// traceAcquire prepares this M for writing one or more trace events.
//