VIPS: simple, efficient, and scalable cache coherence

Directory-based cache coherence is the de-facto standard for scalable shared-memory multi/many-cores and significant effort is invested in reducing its overhead. However, directory area and complexity optimizations are often antithetical to each other. This talk presents VIPS, a family of cache coherence protocols based on self-invalidation and self-downgrade. VIPS protocols remove the complexity and cost associated with directories in their entirety, thus increasing multiprocessors scalability, and at the same time, provide better performance and energy efficiency than traditional directory-based protocols

Invariantly universal analytic quasi-orders

We introduce the notion of an invariantly universal pair (S,E) where S is an analytic quasi-order and E \subseteq S is an analytic equivalence relation. This means that for any analytic quasi-order R there is a Borel set B invariant under E such that R is Borel bireducible with the restriction of S to B. We prove a general result giving a sufficient condition for invariant universality, and we demonstrate several applications of this theorem by showing that the phenomenon of invariant universality is widespread. In fact it occurs for a great number of complete analytic quasi-orders, arising in different areas of mathematics, when they are paired with natural equivalence relations.Comment: 31 pages, 1 figure, to appear in Transactions of the American Mathematical Societ

Wrong-Path-Aware Entangling Instruction Prefetcher

© 2023.IEEE. This document is made available under the CC-BY 4.0 license http://creativecommons.org/licenses/by /4.0/ This document is the Accepted version of a Published Work that appeared in final form in IEEE Transactions on Computers. To access the final edited and published work see DOI 10.1109/TC.2023.3337308Instruction prefetching is instrumental for guaranteeing a high flow of instructions through the processor front end for applications whose working set does not fit in the lowerlevel caches. Examples of such applications are server workloads, whose instruction footprints are constantly growing. There are two main techniques to mitigate this problem: fetch directed prefetching (or decoupled front end) and instruction cache (L1I) prefetching. This work extends the state-of-the-art Entangling prefetcher to avoid training during wrong-path execution. Our Entangling wrong-path-aware prefetcher is equipped with microarchitectural techniques that eliminate more than 99% of wrong-path pollution, thus reaching 98.9% of the performance of an ideal wrongpath-aware solution. Next, we propose two microarchitectural optimizations able to further increase performance benefits by 1.8%, on average. All this is achieved with just 304 bytes. Finally, we study the interplay between the L1I prefetcher and a decoupled front end. Our analysis shows that due to pollution caused by wrong-path instructions, the degree of decoupling cannot be increased unlimitedly without negative effects on the energy-delay product (EDP). Furthermore, the closer to ideal is the L1I prefetcher, the less decoupling is required. For example, our Entangling prefetcher reaches an optimal EDP with a decoupling degree of 64 instructions

Hans Blumenberg: filosofía y la literatura entre 1952 y 1958

From 1952 to 1958 Hans Blumenberg [1920-1996] wrote five philosophical reviews on literature published in the German journal Hochland that have received very little attention by the scholars. This paper focus on Blumenberg’s early reviews devoted to Franz Kafka [1883-1924], Evelyn Waugh [1903-1966], Ernest Hemingway [1899-1961], Thomas S. Eliot [1888- 1965] and William Faulkner [1897-1962].Entre 1952 y 1958 Hans Blumenberg [1920-1996] escribió cinco reseñas literarias, de marcado carácter filosófico, para la revista alemana Hochland. Estas reseñas han recibido muy poca atención por parte de los especialistas interesados en el pensamiento de Blumenberg. En este artículo abordaremos sus análisis tempranos de la obra de Franz Kafka [1883-1924], Evelyn Waugh [1903-1966], Ernest Hemingway [1899-1961], Thomas S. Eliot [1888-1965] y William Faulkner [1897-1962]

Diet-disease relationships : recent advances in nutritional epidemiology

Nutritional epidemiology currently studies the diet-disease relationships. In order to evaluate these associations, an accurate estimation of nutritional exposure is essential. Traditional dietary questionnaires are being complemented with the measurement of nutritional biomarkers. New methodologies, including the use of new dietary assessments, metabolomics for increasing the quantity and quality of biomarkers, and statistical approaches to combine both techniques, are required to move forward in this field. In this review, we have selected five of the more relevant accomplishments in this field as examples of the importance of dietary factors in the prevention of non-communicable diseases. This theoretical knowledge needs to be finally translated by public health experts into dietary recommendations to the general population

Joint coarse-and-fine reasoning for deep optical flow

© 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.We propose a novel representation for dense pixel-wise estimation tasks using CNNs that boosts accuracy and reduces training time, by explicitly exploiting joint coarse-and-fine reasoning. The coarse reasoning is performed over a discrete classification space to obtain a general rough solution, while the fine details of the solution are obtained over a continuous regression space. In our approach both components are jointly estimated, which proved to be beneficial for improving estimation accuracy. Additionally, we propose a new network architecture, which combines coarse and fine components by treating the fine estimation as a refinement built on top of the coarse solution, and therefore adding details to the general prediction. We apply our approach to the challenging problem of optical flow estimation and empirically validate it against state-of-the-art CNN-based solutions trained from scratch and tested on large optical flow datasets.Peer ReviewedPostprint (author's final draft

On isometry and isometric embeddability between ultrametric Polish spaces

We study the complexity with respect to Borel reducibility of the relations of isometry and isometric embeddability between ultrametric Polish spaces for which a set $D$ of possible distances is fixed in advance. These are, respectively, an analytic equivalence relation and an analytic quasi-order and we show that their complexity depends only on the order type of $D$. When $D$ contains a decreasing sequence, isometry is Borel bireducible with countable graph isomorphism and isometric embeddability has maximal complexity among analytic quasi-orders. If $D$ is well-ordered the situation is more complex: for isometry we have an increasing sequence of Borel equivalence relations of length $\omega_1$ which are cofinal among Borel equivalence relations classifiable by countable structures, while for isometric embeddability we have an increasing sequence of analytic quasi-orders of length at least $\omega+3$. We then apply our results to solve various open problems in the literature. For instance, we answer a long-standing question of Gao and Kechris by showing that the relation of isometry on locally compact ultrametric Polish spaces is Borel bireducible with countable graph isomorphism.Comment: Minor imprecisions corrected. Following the suggestion of the anonymous referee, the former Section 7 concerning arbitrary Polish spaces with fixed set of distances has been left out and will be posted as a separate paper soon. The title is changed as well to reflect this modificatio

Ictiólogos de la Argentina: Alberto Nani.

En esta serie se mencionan a todos aquellos que, a través de sus pequeños o grandes aportes, contribuyeron a la consolidación de la disciplina en nuestro país. El plan general de esta contribución consiste en la elaboración de fichas individuales que contengan una lista de trabajos de los diferentes autores, acompañadas por bibliografía de referencia y, cuando ello fuera posible, por imágenes personales y material adicional. Se tratará de guardar un orden cronológico, pero esto no es excluyente, ya que priorizaremos las sucesivas ediciones al material disponible. Este es otro camino para rescatar y revalorizar a quienes en diversos contextos históricos sentaron las bases de lo que hoy es la ictiología nacional. Considero que este es el comienzo de una obra de mayor magnitud en la que se logre describir una parte importante de la historia de las ciencias naturales de la República Argentina