Page 28 - slides.dvi

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2.
1.
Operating
need
CPU
Observe
Systems
CPU-I/O
bursts.
Processes
—
execution,
most
can
I/O-bound:
I/O
Process
bursts.
CPU-bound:
Burst
be
Burst
wait,
Life-cycle
spends
Cycle:
spends
processes
multiprogramming
CPU
Cycle
Frequency CPU-I/O
to
described
more
more
as
process
2
execute
time
time
obtain
4
for
execution,
either:
.
at
6
doing
.
doing
.
execution
decent
8
I/O
most
10
a
overall
12
than
consists
few
CPU Burst Duration (ms)
14
of
CPU
computations;
16
an
has
computation;
milliseconds
few
on-going
utilization.
has
very
before
cycle
many
long
of
CPU
short
CPU
blocking
24