CS5460: Operating Systems

Pg

Description

• mémoire
• mémoire - matière potentielle : organization
• mémoire - matière potentielle : initialization
• mémoire - matière potentielle : scheme
• mémoire - matière potentielle : zload

CS 5460: Operating Systems Project 3 Tutorial CS5460: Operating Systems Project 3 Tutorial -- some hints

• pcb data
• code segment data segment vmem
• page table for region
• paged memory scheme
• stack pages
• kernel stack
• free frames pmem
• page
• data

Sujets

• Mémoire
• Organization
• Initialization
• Scheme
• Numbers
• Kernel
• Memory
• Segment
• Frames

Informations

• Publié par: phewyag
• Nombre de lectures: 12
• Langue: English

Extrait

The principle of utility determines the rightness of acts (or of rules of action) by how they affect the total happiness in the world.

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Its simplest interpretation takes “tend” as referring toactualconsequences of specific acts, but it will be modified later to apply to general rules or types of act.

The principle is identified with Mill’s predecessor Bentham’s “Greatest Happiness Principle,” understood as referring tototalhappiness (vs. the number of people made happy) and extending to all sentient beings.

But for Mill, unlike Bentham, happiness isn’t just a mathematical sum of pleasures minus pains, differing only on quantitative measures like intensity and duration.

Pleasures of distinctively human faculties are also said to be superior inqualityto pleasures of the sort we share with animals – as determined by those who’ve experienced (and are still capable of experiencing) both sorts of pleasure.

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seem to promote the total good, and (relatedly)

why we condemninjustice, sometimes even where a particular unjust act seems to promote the total good.

Mill deals explicitly with the first set of objections toward the end of ch. 2, treating rules as summaries of human experience in applying the principle of utility over time.

He addresses questions of justice in ch. 5, but there he seems to be applying the principle of utility to rules themselves rather than to specific acts.

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just one’s own, is the standard of right action (vs. motive of the virtuous agent).

of utilitarianism:

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leaves no room for beauty, ornament, amusement (p. 54). popular misconception

a “godless” doctrine (p. 68). Spells out what a good and wise God would want.

undercuts “principled” adherence to rules(pp. 68ff.): Rule-breaking is almost always forbidden because of harmful side-effects. Established rules sum up the general tendencies of acts to promote utility, so they serve as a better guide to decision-making at the time of action. We should limit direct appeal to the principle of utility to cases where the rules conflict.

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to utilitarianism

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from justice: Utilitarianism allows for “interpersonal trade-offs,” or the sacrifice of some to the good of all, as indicated by both economic examples and punishment of one innocent person to prevent a riot that would kill many (“telishment”; cf. Rawls). Cf. also “the trolley case” of killing one person to save others.

from moral emotion: Utilitarian calculations would alienate an agent from his moral sentiments e.g. in cases where it would recommend killing one innocent person to prevent the murder of several others (Williams).

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punishments for wrong action), set up or modifiable by society, but ultimately a matter of subjective feeling:

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externalpunishment, social disapproval, etc.: legal

internalof self-reproach, i.e. conscience: feelings

Human social feelings provide a natural basis for concern with the total happiness in the desire for unity with others. But this needs to be widened out beyond one’s family and friends by education.

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The general happiness is desirable: inference from parts to whole [?]

Nothing other than happiness is desirable: anything else is originally desired only as means to it, though certain aims such as virtue can come to be desired for their own sake, as parts of happiness for a particular individual (cf. Mill’s analogy to money). In the end, Mill says that “desirable” and “pleasant” are just different names for the same thought;

The move from hedonism to utilitarianism also depends on Mill’s assumption (see, e.g., pp. 84f.) that the criterion of right action must be supplied by the end for which we act, which amounts to something we view at the time as desirable [=good].

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punishment.

[In light of what Mill goes on to say about justice, we might think this amounts to a claim that the type of act that counts as wrong is expedientto punish. So the principle of utility favors adopting a rule to punish that type of act, rather than just telling people that it’s not the right thing to do. ]

So some acts that fail to maximize the good may not really be wrong but just “inexpedient,” i.e. non-optimal.

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 . more fully specified duties are known as“perfect” duties; the persons toward whom we have such duties are said to haverights.

The particularly strong sense of obligation associated with justice results from our natural retaliatory sentiments, but becomes amoralsentiment, the sentiment of justice, only when our urge toward self-defense is extended by sympathy, to reflect concern for general utility.

The upshot is that justice is explained by the principle of utility, but as applied to general rules rather than acts. However, Mill adds that the rules can be overridden in extreme circumstances (pp. 106f.).

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they’re in accordance with rules that, if generally followed, would have the best consequences.

Rather than merely summing up past experience with applying the principle of utility directly to acts, rules describe general practices to which the principle applies (cf. rules of a game).

However, rule-utilitarianism. as this approach is called, is subject to the objection that it “collapses into” act-utilarianism: if we really care about the general happiness, then in a case where it’s clear that adhering to the rules would undermine it, we should violate the rules (as Mill says when he allows for exceptions).