Cache-Integrated Network Interfaces: Flexible On-Chip Communication and Synchronization for Large-Scale CMPs

Per-core scratchpad memories (or local stores) allow direct inter-core communication, with latency and energy advantages over coherent cache-based communication, especially as CMP architectures become more distributed. We have designed cache-integrated network interfaces, appropriate for scalable multicores, that combine the best of two worlds – the flexibility of caches and the efficiency of scratchpad memories: on-chip SRAM is configurably shared among caching, scratchpad, and virtualized network interface (NI) functions. This paper presents our architecture, which provides local and remote scratchpad access, to either individual words or multiword blocks through RDMA copy. Furthermore, we introduce event responses, as a technique that enables software configurable communication and synchronization primitives. We present three event response mechanisms that expose NI functionality to software, for multiword transfer initiation, completion notifications for software selected sets of arbitrary size transfers, and multi-party synchronization queues. We implemented these mechanisms in a four-core FPGA prototype, and measure the logic overhead over a cache-only design for basic NI functionality to be less than 20%. We also evaluate the on-chip communication performance on the prototype, as well as the performance of synchronization functions with simulation of CMPs with up to 128 cores. We demonstrate efficient synchronization, low-overhead communication, and amortized-overhead bulk transfers, which allow parallelization gains for fine-grain tasks, and efficient exploitation of the hardware bandwidth.

Medically unexplained symptoms: The need for effective communication and an integrated care strategy

Much is already known about medically unexplained symptoms (MUS) in terms of incidence, presentation and current treatment. What needs to be urgently addressed is a strategy for dealing with patients and their conditions, particularly when they do not fall neatly into medical frameworks or pathologies where the syndrome can be easily explained. This article will consider the provision of health and social care support for patients with MUS within an interprofessional education context. The author will contend that a sensitive and valued service for this large client group is dependent upon services without professional boundaries and practitioners with a clinical interest that can work together and agree an appropriate way forward in terms of care, support and strategic service provision. The article will support the idea that clear guidelines through the National Institute for Health and Care Excellence can offer clear clinical direction for practitioners working in primary and secondary care settings to work together interprofessionally to ensure a seamless and sensitive service for people with this condition.