Combining software cache partitioning and loop tiling for effective shared cache management

One of the biggest challenges in multicore platforms is shared cache management, especially for data dominant applications. Two commonly used approaches for increasing shared cache utilization are cache partitioning and loop tiling. However, state-of-the-art compilers lack of efficient cache partitioning and loop tiling methods for two reasons. First, cache partitioning and loop tiling are strongly coupled together, thus addressing them separately is simply not effective. Second, cache partitioning and loop tiling must be tailored to the target shared cache architecture details and the memory characteristics of the co-running workloads. To the best of our knowledge, this is the first time that a methodology provides i) a theoretical foundation in the above mentioned cache management mechanisms and ii) a unified framework to orchestrate these two mechanisms in tandem (not separately). Our approach manages to lower the number of main memory accesses by an order of magnitude keeping at the same time the number of arithmetic/addressing instructions in a minimal level. We motivate this work by showcasing that cache partitioning, loop tiling, data array layouts, shared cache architecture details (i.e., cache size and associativity) and the memory reuse patterns of the executing tasks must be addressed together as one problem, when a (near)- optimal solution is requested. To this end, we present a search space exploration analysis where our proposal is able to offer a vast deduction in the required search space

Cache partitioning + loop tiling: A methodology for effective shared cache management

In this paper, we present a new methodology that provides i) a theoretical analysis of the two most commonly used approaches for effective shared cache management (i.e., cache partitioning and loop tiling) and ii) a unified framework to fine tuning those two mechanisms in tandem (not separately). Our approach manages to lower the number of main memory accesses by one order of magnitude keeping at the same time the number of arithmetical/addressing instructions in a minimal level. We also present a search space exploration analysis where our proposal is able to offer a vast deduction in the required search space

Ovarian vein thrombosis mimicking acute abdomen: a case report and literature review

<p>Abstract</p> <p>Background</p> <p>Ovarian vein thrombosis (OVT) is a rare, but serious condition that affects mostly postpartum women. A high index of suspicion is required in order to diagnose this unusual cause of abdominal pain.</p> <p>Case presentation</p> <p>A 19-year-old woman at three days postpartum was admitted to our hospital because of severe right lower quandrant abdominal pain and fever 38.5'C. Physical examination revealed an acutely ill patient and right lower quadrant tenderness with positive rebound and Giordano signs. The patient underwent appendectomy which proved to be negative for acute appendicitis. Postoperatively fever and pain persisted and abdominal CT-scan with intravenous contrast agent demonstrated a thrombosed right ovarian vein. The patient was initiated on low-molecular weight heparin (LMWH) and antibiotic treatment and a month later a new abdominal CT-scan showed a patent right ovarian vein.</p> <p>Discussion</p> <p>Pathophysiologically, OVT is explained by Virchow's triad, because pregnancy is associated with a hypercoagulable state, venous stasis due to compression of the inferior vena cava by the uterus and endothelial trauma during delivery or from local inflammation. Common symptoms and signs of OVT include lower abdomen or flank pain, fever and leukocytosis usually within the first ten days after delivery. The reported incidence of OVT ranges 0,05-0,18% of pregnancies and in most cases the right ovarian vein is the one affected. Anticoagulation and antibiotics is the mainstay of treatment of OVT. Complications of OVT include sepsis, extension of the thrombus to the inferior vena cava and renal veins, and pulmonary embolism. The incidence of pulmonary embolism is reported to be 13.2% and represents the main source of mortality due to OVT.</p> <p>Conclusions</p> <p>OVT is a rare condition, usually in the postpartum period. A high index of suspicion is required for the prompt diagnosis and management especially in cases that mimic acute abdomen.</p

Model-based Development of Enhanced Ground Proximity Warning System for Heterogeneous Multi-Core Architectures

The aerospace domain, very much similar to other cyber-physical systems domains such as automotive or automation, is demanding new methodologies and approaches for increasing performance and reducing cost, while maintaining safety levels and programmability. While the heterogeneous multi-core architectures seem promising, apart from certification issues, there is a solid necessity for complex toolchains and programming processes for exploiting their full potential. The ARGO (WCET-Aware PaRallelization of Model-Based Ap-plications for HeteroGeneOus Parallel Systems) project is addressing this challenge by providing an inte-grated toolchain that realizes an innovative holistic approach for programming heterogeneous multi-core sys-tems in a model-based workflow. Model-based design elevates systems modeling and promotes simulation with the executing these models for verification and validation of the design decisions. As a case study, the ARGO toolchain and workflow will be applied to a model-based Enhanced Ground Proximity Warning System (EGPWS) development. EGPWS is a readily available system in current aircraft which provides alerts and warnings for obstacles and terrain along the flight path utilizing high resolution terrain databases, Global Positioning System and other sensors-. After a gentle introduction to the model-based development approach of the ARGO project for the heterogeneous multi-core architectures, the EGPWS and the EGPWS systems modelling will be presented

Association between biliary complications and technique of hilar division (extrahepatic vs. intrahepatic) in major liver resections

BACKGROUND: Division of major vascular and biliary structures during major hepatectomies can be carried out either extrahepatically at the porta hepatic or intrahepatically during the parenchymal transection. In this retrospective study we test the hypothesis that the intrahepatic technique is associated with less early biliary complications. METHODS: 150 patients who underwent major hepatectomies were retrospectively allocated into an intrahepatic group (n = 100) and an extrahepatic group (n = 50) based on the technique of hilar division. The two groups were operated by two different surgical teams, each one favoring one of the two approaches for hilar dissection. Operative data (warm ischemic time, operative time, blood loss), biliary complications, morbidity and mortality rates were analyzed. RESULTS: In extrahepatic patients, operative time was longer (245 ± 50 vs 214 ± 38 min, p < 0.05) while the overall complication rate (55% vs 52%), hospital stay (13 ± 7 vs 12 ± 4 days), bile leak rate (22% vs 20%) and mortality (2% vs 2%) were similar compared to intrahepatic patients. However, most (57%) bile leaks in extrahepatic patients were grade II (leaks that required non-operative interventional treatment, while most (70%) leaks in the intrahepatic group were grade I (leaks that resolved and presented two injuries (4%) of the remaining bile ducts (p < 0.05). CONCLUSION: Intrahepatic hilar division is as safe as extrahepatic hilar division in terms of intraoperative blood requirements, morbidity and mortality. The extrahepatic technique is associated with more severe bile leaks and biliary injuries

Cyberphysical systems for epilepsy and related brain disorders: multi-parametric monitoring and analysis for diagnosis and optimal disease management

This book introduces a new cyberphysical system that combines clinical and basic neuroscience research with advanced data analysis and medical management tools for developing novel applications for the management of epilepsy. The authors describe the algorithms and architectures needed to provide ambulatory, diagnostic and long-term monitoring services, through multi parametric data collection. Readers will see how to achieve in-hospital quality standards, addressing conventional “routine” clinic-based service purposes, at reduced cost, enhanced capability, and increased geographical availability. The cyberphysical system described in this book is flexible, can be optimized for each patient, and is demonstrated in several case studies