252 research outputs found
Compilação Just-In-Time: Histórico, Arquitetura, Princípios e Sistemas
Get PDFDiversas implementações de linguagens de alto nível focam no desenvolvimento de sistemas baseados em mecanismos de compilação just-in-time. Esse mecanismo possui o atrativo de melhorar o desempenho de tais linguagens, mantendo a portabilidade. Contudo, ao preço da inclusão do tempo de compilação ao tempo total de execução. Diante disso, as pesquisas na área têm voltado balancear o custo de compilação com eficiência de execução. Os primeiros sistemas de compilação just-in-time empregavam estratégias estáticas para selecionar e otimizar as regiões de código propícias para gerar bom desempenho. Sistemas mais sofisticados aprimoraram tais estratégias com o objetivo de aplicar otimizações de forma mais criteriosa. Nesse sentido, este tutorial apresenta os princípios que fundamentam a compilação just-in-time e sua evolução ao longo dos anos, bem como a abordagem utilizada por diversos sistemas para garantir o balanceamento de custo e eficiência. Embora seja difícil definir a melhor abordagem, trabalhos recentes mostram que estratégias rígidas para detecção e otimização de código, juntamente com recursos de paralelismo oferecidos pelas arquiteturas multi-core formarão a base dos futuros sistemas de compilação just-in-time
Dataplane Specialization for High-performance OpenFlow Software Switching
Get PDFOpenFlow is an amazingly expressive dataplane program-
ming language, but this expressiveness comes at a severe
performance price as switches must do excessive packet clas-
sification in the fast path. The prevalent OpenFlow software
switch architecture is therefore built on flow caching, but
this imposes intricate limitations on the workloads that can
be supported efficiently and may even open the door to mali-
cious cache overflow attacks. In this paper we argue that in-
stead of enforcing the same universal flow cache semantics
to all OpenFlow applications and optimize for the common
case, a switch should rather automatically specialize its dat-
aplane piecemeal with respect to the configured workload.
We introduce ES WITCH , a novel switch architecture that
uses on-the-fly template-based code generation to compile
any OpenFlow pipeline into efficient machine code, which
can then be readily used as fast path. We present a proof-
of-concept prototype and we demonstrate on illustrative use
cases that ES WITCH yields a simpler architecture, superior
packet processing speed, improved latency and CPU scala-
bility, and predictable performance. Our prototype can eas-
ily scale beyond 100 Gbps on a single Intel blade even with
complex OpenFlow pipelines
Letter from J. L. Heigh to John Muir, 1863 Nov 14
Get PDF[4] Blake has been confined to his room with a sore throat for some days past, and Stein, poor little Hebrew has been quite sick but is doing finely now. I have taken care of him for the past four days and my treatment has been so emuiently successful that I am led to think I have mistaken my profession and had better become a disciple of Sesculapuis than to follow Blackstone & Kent. Your inquiry about the prosperity of the churches. I am hardly prepared to answer as I attend non but the Baptist. it is however in a prosperous condition. The first Sabbath of this term Mr Johnson admitted nearly twenty numbers, and some have been taken in since. You counsel me not to forget the things of Eternity. Be assured that I do not - but as you well know the influences surrounding me here are terrible as well in their effects as in their nature. But I trust it is not all down hill with me, after all. Accept my kindest wishes and believe me Yours etc. J. L. [Heigh?].633Patrick says he sent the boxes more than a month since, and that the Ann Arbor direction was carefully erased with a p[illegible][1] Madison Wis. Nov. 14th 1863. Dear Muir, Better late than never , re an adage applicable as well to epistolary correspondence as to most other human affairs, and your letter came just in time to save your reputation for truth and vesacity I should have written to spur you up but I did not know where to direct. We are jogging along in the good old style here on the hill. The term is a full one and thus far very pleasant. There have been in all about two hundred and thirty students about equally divided as to sex. We wind up in about ten days more and then for my writers work. 00340 [2]I shall teach at home again and anticipate a pleasant winter with mother and father, probably the last winter I shall ever spend at home. My chum the good- natured Wallace did not return until last week but he intends to stay right through the year. Our class numbers only five [org.?] Wallace, Spooner, Salisbury Cuger, and myself. Leahey has gone into the army, and Lewis is a Senior at Union College N. T. So as you see we are small in numbers but we are making a brave fight of it nevertheless. The Societies are doing unusually well this term. Yours numbers about twenty five members and ours over forty. Mc Laughlin was elected Pres. of yours last night Big thing for a small boy isn\u27t it? He is if possible noisier than ever.[3]Our mutual friends the Griffins no longer occupy the house at the foot of the hill . They have moved to the Depot and keep the Eating Saloon there. I have called only once since they have moved. They are well all around and the girls spoke about your letter. Miss Flora is in my German class where I meet her every day. In regard to the legal business you wished me to do I submit the following report. Lewis had paid Patrick for the table and Pat gave me the money which I send enclosed. [Viebahn?] I have not seen for more than a year. He is still teaching at Sauk City. Blachly left about three weeks since being out of funds, so I have had no opportunity of collecting anything from him. He will probably be back next term
Valley View, Vol. 02, No. 08, November 16, 1967
Get PDFThe Valley View was a weekly student newspaper supported by GVSC and published from October 28, 1966 to June 6, 1968. Continuation of Keystone, renamed Lanthorn in 1968
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