Memory reclamation for sequential or lock-based data structures is typically easy. However, memory reclamation for lock-free data structures is a significant challenge. Automatic techniques such as garbage collection are inefficient or use locks, and non-automatic techniques either have high overhead, or do not work for many reasonably simple data structures. For example, subtle problems can arise when hazard pointers, one of the most common non-automatic techniques, are applied to many natural lock-free data structures. Epoch based reclamation (EBR), which is by far the most efficient non-automatic technique, allows the number of unreclaimed objects to grow without bound, because one slow or crashed process can prevent all other processes from reclaiming memory. We develop a more efficient, distributed variant of EBR that solves this problem. It is based on signaling, which is provided by many operating systems, such as Linux and UNIX. Our new scheme takes O(1) amortized steps pe...