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comp.unix.aix Frequently Asked Questions (Part 2 of 5)
Section - 1.306: Why do PIDs run non-sequentially?

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The answer (I was there, consider me an authority ...) is that the
PIDs needed to be somewhat unpredictable.  This is because AIX was
originally designed with a number of C2 and B1 features, and one of those
is the notion of covert channel analysis.  Sequential PIDs are a covert
channel (assuming the system has one PID namespace ...) since the value
of the "next" PID is shared by all currently running processes.  So if I
want to sneak some of my classified data out to your co-operating
non-classified program, I can do it by carefully controlling the value
of the "next" PID.

User Contributions:

MELIN
Report this comment as inappropriate
Dec 8, 2017 @ 3:15 pm
Compare and contrast a process and a thread?



As a job, a process, or a thread moves through a system, its status changes, often from HOLD, to READY, to RUNNING, to WAITING and eventually to FINISHED. What are some common reasons why these statuses can change? Define in minor detail what each status means.





The Process Scheduler relies on a scheduling algorithm, based on a specific scheduling policy, to allocate the CPU in the best way to move jobs through the system efficiently. Most systems place an emphasis on fast user response time. Your text book refers to these algorithms as "process scheduling algorithms". Please identify at least four (4) of these algorithms and briefly explain each (one to two paragraphs per alogorithm).



Briefly explain the purpose of a PID and then explain how a process is assigned a PID by the operating system?

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Top Document: comp.unix.aix Frequently Asked Questions (Part 2 of 5)
Previous Document: 1.305: How much RAM (real memory) does my machine have?
Next Document: 1.400: How do I make an informative prompt in the shell?

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Last Update March 27 2014 @ 02:11 PM