A comparative study of arbitration algorithms for the Alpha 21364 pipelined router

Interconnection networks usually consist of a fabric of interconnected routers, which receive packets arriving at their input ports and forward them to appropriate output ports. Unfortunately, network packets moving through these routers are often delayed due to conflicting demand for resources, such as output ports or buffer space. Hence, routers typically employ arbiters that resolve conflicting resource demands to maximize the number of matches between packets waiting at input ports and free output ports. Efficient design and implementation of the algorithm running on these arbiters is critical to maximize network performance.This paper proposes a new arbitration algorithm called SPAA (Simple Pipelined Arbitration Algorithm), which is implemented in the Alpha 21364 processor's on-chip router pipeline. Simulation results show that SPAA significantly outperforms two earlier well-known arbitration algorithms: PIM (Parallel Iterative Matching) and WFA (Wave-Front Arbiter) implemented in the SGI Spider switch. SPAA outperforms PIM and WFA because SPAA exhibits matching capabilities similar to PIM and WFA under realistic conditions when many output ports are busy, incurs fewer clock cycles to perform the arbitration, and can be pipelined effectively. Additionally, we propose a new prioritization policy called the Rotary Rule, which prevents the network's adverse performance degradation from saturation at high network loads by prioritizing packets already in the network over new packets generated by caches or memory.Mukherjee, S.; Silla Jiménez, F.; Bannon, P.; Emer, J.; Lang, S.; Webb, D. (2002). A comparative study of arbitration algorithms for the Alpha 21364 pipelined router. ACM SIGPLAN Notices. 37(10):223-234. doi:10.1145/605432.605421S223234371

Implementing palliative care, based on family-centered care, in a highly complex neonatal unit

Objective: To describe the causes and circumstances of neonatal mortality and determine whether the implementation of a palliative care protocol has improved the quality of end-of-life care. Methods: A retrospective observational study including all patient mortalities between January 2009 and December 2019. Cause of death and characteristics of support during the dying process were collected. Two periods, before and after the implementation of a palliative care protocol, were compared. Results: There were 344 deaths. Congenital malformations were the most frequent cause of death (45.6 %). Most patients died after the transition to palliative care (74.4 %). The most frequently cited criteria for initiating transition of care was poor neurocognitive prognosis (47.2 %). Parents accompanied their children in the dying process in 72 % of cases. Twenty-three percent of patients died outside the Neonatal Intensive Care Unit after being transferred to a private room to enhance family intimacy. After the addition of the palliative care protocol, statistically significant differences were observed in the support and patient experience during the dying process. Conclusions: The most frequent causes of death were severe congenital malformations. Most patients died accompanied by their parents after the transition to palliative care. The implementation of a palliative care protocol helped to improve the family-centered end-of-life care