5,634 research outputs found
Fine-Grain Checkpointing with In-Cache-Line Logging
Non-Volatile Memory offers the possibility of implementing high-performance,
durable data structures. However, achieving performance comparable to
well-designed data structures in non-persistent (transient) memory is
difficult, primarily because of the cost of ensuring the order in which memory
writes reach NVM. Often, this requires flushing data to NVM and waiting a full
memory round-trip time.
In this paper, we introduce two new techniques: Fine-Grained Checkpointing,
which ensures a consistent, quickly recoverable data structure in NVM after a
system failure, and In-Cache-Line Logging, an undo-logging technique that
enables recovery of earlier state without requiring cache-line flushes in the
normal case. We implemented these techniques in the Masstree data structure,
making it persistent and demonstrating the ease of applying them to a highly
optimized system and their low (5.9-15.4\%) runtime overhead cost.Comment: In 2019 Architectural Support for Programming Languages and Operating
Systems (ASPLOS 19), April 13, 2019, Providence, RI, US
A NWB-based dataset and processing pipeline of human single-neuron activity during a declarative memory task
A challenge for data sharing in systems neuroscience is the multitude of different data formats used. Neurodata Without Borders: Neurophysiology 2.0 (NWB:N) has emerged as a standardized data format for the storage of cellular-level data together with meta-data, stimulus information, and behavior. A key next step to facilitate NWB:N adoption is to provide easy to use processing pipelines to import/export data from/to NWB:N. Here, we present a NWB-formatted dataset of 1863 single neurons recorded from the medial temporal lobes of 59 human subjects undergoing intracranial monitoring while they performed a recognition memory task. We provide code to analyze and export/import stimuli, behavior, and electrophysiological recordings to/from NWB in both MATLAB and Python. The data files are NWB:N compliant, which affords interoperability between programming languages and operating systems. This combined data and code release is a case study for how to utilize NWB:N for human single-neuron recordings and enables easy re-use of this hard-to-obtain data for both teaching and research on the mechanisms of human memory
Implications of Combination of Operating Systems and Programming Languages on Parallel Programming Efficiency
There are a number of programming languages and operating systems, and the appropriate selection of the two depends on the type of application. The effective application of parallel programming depends on a number of factors such as hardware and software, the application type, and the cost. At the micro level, understanding the concepts of threading, processors, and memory are also critical factors in deciding the type of parallel programming to use. The purpose of this paper is to discuss the impact of different combinations of operating systems and programming languages on the efficiency of parallel programming
Near-Memory Address Translation
Memory and logic integration on the same chip is becoming increasingly cost
effective, creating the opportunity to offload data-intensive functionality to
processing units placed inside memory chips. The introduction of memory-side
processing units (MPUs) into conventional systems faces virtual memory as the
first big showstopper: without efficient hardware support for address
translation MPUs have highly limited applicability. Unfortunately, conventional
translation mechanisms fall short of providing fast translations as
contemporary memories exceed the reach of TLBs, making expensive page walks
common.
In this paper, we are the first to show that the historically important
flexibility to map any virtual page to any page frame is unnecessary in today's
servers. We find that while limiting the associativity of the
virtual-to-physical mapping incurs no penalty, it can break the
translate-then-fetch serialization if combined with careful data placement in
the MPU's memory, allowing for translation and data fetch to proceed
independently and in parallel. We propose the Distributed Inverted Page Table
(DIPTA), a near-memory structure in which the smallest memory partition keeps
the translation information for its data share, ensuring that the translation
completes together with the data fetch. DIPTA completely eliminates the
performance overhead of translation, achieving speedups of up to 3.81x and
2.13x over conventional translation using 4KB and 1GB pages respectively.Comment: 15 pages, 9 figure
- …