As systems become more complex, there are increasing demands for improvement with respect to attributes such as performance, dependability, and security. Optimization is defined as theprocess of making the most effective use of a set of resources with respect to some attribute. Existing optimization techniques, however, have two fundamental limitations. They target individual parts of a system without considering the potentially significant global picture, and they are designed to improve a single attribute at a time. These limitations impose significant restrictions on the kinds of optimization possible, the effectiveness of the techniques, and the ability to improvethe optimization process itself.This dissertation presents holistic system optimization, a new approach to optimization based on taking a broad view of a system. Unlike current approaches, holistic optimizations consider different kinds of interactions at multiple levels in a system, and target a variety of metrics uniformly. A key component of this research has been the use of proven compiler techniques to ensure transparency, automation, and correctness. These techniques have been implemented in Cassyopia, a software prototype of a framework for performing holistic optimization.The core of this work is three new holistic optimizations, which are also presented. The first describes profile-directed static optimizations designed to improve the performance of eventbased programs by spanning boundaries that separate code that raises events from handlers that field them. The second, system call clustering, improves the system call behavior of an entire program by grouping together calls that can be executed in a single boundary crossing. In thiscase, the optimization spans kernel and user address spaces. Finally, authenticated system calls optimize system security through a novel implementation of an efficient system call monitor. This example demonstrates how the new approach can be used to create new optimizations that not only span address space boundaries but also target attributes such as dependability. All of these optimizations involve the application of standard compiler techniques in non-traditional contexts and demonstrate how systems can be improved beyond what is possible using existing techniques.

Våra hem fylls med produkter baserade på behov och önskemål och användningenav produkterna avtar efter en kortare tid då behovet att ersätta produkterna mednya känns lockande. Samhället är byggt för att avfallssystemet skall kunna ta övervåra produkter som vi inte längre använder.Den här studien undersöker hur man genom design kan uppmuntra till attanvända befintliga produkter i hemmet som man tröttnat på genom att omformadem. Studien stödjs av teoretiska grunder såsom hållbar utveckling, cirkulärekonomi, emotionell design, redesign och kritisk design. Empirin bestod avpilotstudie och semistrukturerade intervjuer med studiens målgrupp, som ärmiljömedvetna med en strävan efter en mer hållbar livsstil och som inte är direkttrendsökare.En omformning av en befintlig produkt studeras genom redesign sommålsättning för ett mer hållbart designförslag. Kritisk design som ett perspektivdiskuterar hur samhällets linjära ekonomi bör utvecklas och yrkesrollens kontextskulle kunna se ut i ett fiktivt, holistiskt system. Syftet är att förebygga ersättandetav nya produkter när man tröttnat på dem genom omformning av en befintligprodukt eller att produkter hamnar i avfallstrappan.Studiens slutsats visar ett alternativt designförslag genom prototyp i skala 1:1av en omformning av en befintlig klädställning, som respondent tröttnat på i sitthem. Designförslaget med en strävan mot ett mer hållbart alternativ som kan genytt liv till produkten och med hopp om återanvändning. Detta sker främst genompersonlig design som designinriktning, som är baserat på användarens uppfattningoch tycke. Ett fiktivt system presenteras i studiens diskussions del genom kritiskdesign och som även framför för hur studiens designförslag kan appliceras i ettstörre system. / Our homes are filled with products based on needs and desires and the useof the products decreases after a shorter period of time, when the need to replacethe products with new ones feels attractive. Society is built to allow the wastesystem to take over our products that we no longer use.This study examines how, through design, you can encourage the use ofexisting products in the home that you are tired of by reshaping them. The study issupported on theoretical grounds such as sustainable development, circulareconomics, emotional design, redesign and critical design. The empirical studyconsisted of a pilot study and semi-structured interviews with the study's targetgroup, who are environmentally conscious with a desire for a more sustainablelifestyle and who are not directly trendsetters.A redesign of an existing product is studied through redesign as the goalof a more sustainable design proposal. Critical design as a perspective discusseshow the linear economy of society should develop and the context of theprofessional role could look like in a fictional, holistic system. The purpose is toprevent the replacement of new products when they are tired of them by reshapingan existing product or that products fall into the waste staircase.The study's conclusion shows an alternative design proposal through a 1: 1scale prototype of a reshaping of an existing clothing rack, which the respondenttired of in his home. The design proposal with a quest for a more sustainablealternative that can give new life to the product and with the hope of reuse. This ismainly done through personal design as a design orientation, which is based onthe user's perception and liking. A holistic, fictitious system is presented throughcritical design that is part of the study discussion that also forms the basis for howthe study's design proposals can be applied in a circular system.