// A StackRecord describes a single execution stack.
type StackRecord struct {
	Stack0 [32]uintptr // stack trace for this record; ends at first 0 entry
}

// Stack returns the stack trace associated with the record,
// a prefix of r.Stack0.
func (r *StackRecord) Stack() []uintptr {
	for i, v := range r.Stack0 {
		if v == 0 {
			return r.Stack0[0:i]
		}
	}
	return r.Stack0[0:]
}

	_FixAllocChunk = 16 << 10 // Chunk size for FixAlloc

	// Per-P, per order stack segment cache size.
	_StackCacheSize = 32 * 1024

	// Number of orders that get caching. Order 0 is FixedStack
	// and each successive order is twice as large.
	// We want to cache 2KB, 4KB, 8KB, and 16KB stacks. Larger stacks
	// will be allocated directly.
	// Since FixedStack is different on different systems, we