Ch. 10 Processes

Question 1

How does linux organize the different programs waiting for their turn at the cpu?

Answer 1

Through Processes

Question 2

what does command ps do

Answer 2

report a snapshot of current processes

Question 3

what does command top do

Answer 3

display taks

Question 4

what does command jobs do

Answer 4

list active jobs

Question 5

what does command bg do

Answer 5

place a job in the background

Question 6

what does command fg do

Answer 6

place a job in the foreground

Question 7

what does command kill do

Answer 7

send a signal to a process

Question 8

what does command killall do

Answer 8

kill processes by name

Question 9

what does command shutdown do

Answer 9

shutdown or reboot the system

Question 10

What is the expression for a program that can launch other programs?

Answer 10

Parent process producing a child process

Question 11

What always has pid1

Answer 11

Init

Question 12

what is pid

Answer 12

Process id. the kernal gives pid in ascending order of startup.

Question 13

What three things does the kernal always track about processes?

Answer 13

1.PID 2. memory assigned to each process 3. processes’ readiness to resume execution

Question 14

The most commonly used command to view processes (there are several)

Answer 14

ps

Question 15

What does TTY tell us

Answer 15

The controlling terminal for the process

Question 16

What is the TIME Field

Answer 16

the amount of cpu time consumed by the process.

Question 17

what does ps tell us by defualt?

Answer 17

only the processes associated with running that terminal.

Question 18

what does ps x do

Answer 18

It tells ps to show all of our processes regardless of what terminal (if any) they are controlled by

Question 19

what does ? in the tty field mean?

Answer 19

No controlling terminal

Question 20

What does Stat tell us?

Answer 20

The state. It reveals the current status of the process

Question 21

Process State R

Answer 21

Running. This means that the process is running or ready to run.

Question 22

Process state S

Answer 22

Sleeping. the process is not running; rather, it is waiting for an event, such as a keystroke or network packet.

Question 23

Process state D

Answer 23

Uninterruptible sleep. The process is waiting for I/o such as a disk drive.

Question 24

Process state T

Answer 24

Stopped. The process has been instructed to stop.

Question 25

Process state Z

Answer 25

A defunct or “zombie” process. This is a child process that has terminated but has not been cleaned up by its parent.

Question 26

process state

Answer 26

a high-priority process. IT’s possible to grant more importance to a process, giving it more time on the cpu. This property of a process is called niceness. A process with high priority is said to be less nice because it’s taking more of the CPU’s time, which leaves less for everybody else

Question 27

process state N

Answer 27

A low-priority process. A process with low priority (a “nice” process) will get processor time only after other processes with higher priority have been serviced

Question 28

what does ps aux do?

Answer 28

displays the processes belonging to eery user

Question 29

CPU usage in percent

Answer 29

%CPU

Question 30

User ID. This is the owner process.

Answer 30

USER

Question 31

Memory usage in percent.

Answer 31

%MEM

Question 32

Virtual memory size

Answer 32

VSZ

Question 33

Resident set size. This is the amount of physical memory (RAM) the process is using in kilobytes

Answer 33

RSS

Question 34

Time when the process started.

Answer 34

START

Question 35

What does the top program display

Answer 35

a continuously updating display of the system processes listed in order of process activity.

Question 36

Where doe the name top come from?

Answer 36

the fact that the top program is used to see the “top” processes on the system.

Question 37

Top display consists of two parts

Answer 37

1. a system summary at the top of the display 2. a table of processes sorted by cpu activity

Question 38

Outputs a process list arranged in a tree-like pattern showing the
parent-child relationships between processes.

Answer 38

pstree

Question 39

Outputs a snapshot of system resource usage including, memory,
swap, and disk I/O. T

Answer 39

vmstat

Question 40

draws a graph showing system load over time

Answer 40

tload. terminate the output with ctrl-c