65 research outputs found
Understanding Memory Access Behavior for Heterogeneous Memory Systems
Present day manufacturers have invented different memory technologies with distinct bandwidth, energy and cost trade-offs. Systems with such heterogeneous memory technologies can only achieve the best performance and power characteristics by appropriately partitioning process data on OS pages and placing OS pages in the right memory areas. To achieve effective data partitioning and placement we need to first understand how programs access memory and how those patterns change at various stages (phases) of program execution. The goal of this work is to build a framework, design experiments and conduct analysis to understand overall memory usage patterns across many programs. We use Intel’s Pin dynamic binary translation and instrumentation system for this work. Our Pin based framework instruments programs at run-time to collect data regarding memory allocations, de-allocations, reads and writes, which we then analyze using our specialized scripts. We collect and analyze information including page access counts, hot page ratio, memory read and write access patterns and how that varies in different program phases. We also analyze the similarities regarding memory behavior between distinct phases during program execution. We also study memory behavior both with cache and without cache to understand how caches affect the memory access behavior
A Morphism Double Category and Monoidal Structure
A double category is constructed from a `fattened' version of a given
category, motivated in part by a context of parallel transport. We also study
monoidal structures on the underlying category and on the fattened category
TWISTED ACTIONS OF CATEGORICAL GROUPS
Abstract. We develop a theory of twisted actions of categorical groups using a notion of semidirect product of categories. We work through numerous examples to demonstrate the power of these notions. Turning to representations, which are actions that respect vector space structures, we establish an analog of Schur’s lemma in this context. Keeping new terminology to a minimum, we concentrate on examples exploring the essential new notions introduced. 1
Negative forms and path space forms
We present an account of negative differential forms within a natural
algebraic framework of differential graded algebras, and explain their
relationship with forms on path spaces.Comment: 12 pp.; the Introduction has been rewritten and mention of cohomology
dropped in Proposition 3.2; material slightly reorganize
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