<s>
Consider	O
an	O
example	O
of	O
a	O
two	O
level	O
cache	B-General_Concept
hierarchy	I-General_Concept
where	O
L2	O
can	O
be	O
inclusive	O
,	O
exclusive	O
or	O
NINE	O
of	O
L1	O
.	O
</s>
<s>
Suppose	O
there	O
is	O
a	O
processor	B-General_Concept
read	O
request	O
for	O
block	O
X	O
.	O
</s>
<s>
If	O
the	O
block	O
is	O
found	O
in	O
L1	O
cache	O
,	O
then	O
the	O
data	O
is	O
read	O
from	O
L1	O
cache	O
and	O
returned	O
to	O
the	O
processor	B-General_Concept
.	O
</s>
<s>
Assume	O
that	O
the	O
processor	B-General_Concept
sends	O
a	O
read	O
X	O
request	O
.	O
</s>
<s>
Now	O
,	O
assume	O
the	O
processor	B-General_Concept
issues	O
a	O
read	O
Y	O
request	O
which	O
is	O
a	O
miss	O
in	O
both	O
L1	O
and	O
L2	O
.	O
</s>
<s>
One	O
example	O
of	O
inclusive	O
cache	O
is	O
Intel	B-Device
quad	I-Device
core	I-Device
processor	I-Device
with	O
4x256KB	O
L2	O
caches	O
and	O
8MB	O
(	O
inclusive	O
)	O
L3	O
cache	O
.	O
</s>
<s>
Suppose	O
there	O
is	O
a	O
processor	B-General_Concept
read	O
request	O
for	O
block	O
X	O
.	O
</s>
<s>
If	O
the	O
block	O
is	O
found	O
in	O
L1	O
cache	O
,	O
then	O
the	O
data	O
is	O
read	O
from	O
L1	O
cache	O
and	O
returned	O
to	O
the	O
processor	B-General_Concept
.	O
</s>
<s>
Here	O
,	O
L2	O
behaves	O
like	O
a	O
victim	B-General_Concept
cache	I-General_Concept
.	O
</s>
<s>
Assume	O
that	O
the	O
processor	B-General_Concept
sends	O
a	O
read	O
X	O
request	O
.	O
</s>
<s>
Now	O
,	O
again	O
the	O
processor	B-General_Concept
issues	O
a	O
read	O
Y	O
request	O
which	O
is	O
a	O
miss	O
in	O
both	O
L1	O
and	O
L2	O
.	O
</s>
<s>
An	O
example	O
of	O
exclusive	O
cache	O
is	O
AMD	B-General_Concept
Opteron	I-General_Concept
with	O
512	O
KB	O
(	O
per	O
core	O
)	O
L2	O
cache	O
,	O
exclusive	O
of	O
L1	O
.	O
</s>
<s>
Suppose	O
there	O
is	O
a	O
processor	B-General_Concept
read	O
request	O
for	O
block	O
X	O
.	O
</s>
<s>
If	O
the	O
block	O
is	O
found	O
in	O
L1	O
cache	O
,	O
then	O
the	O
data	O
is	O
read	O
from	O
L1	O
cache	O
and	O
returned	O
to	O
the	O
processor	B-General_Concept
.	O
</s>
<s>
Assume	O
that	O
the	O
processor	B-General_Concept
sends	O
a	O
read	O
X	O
request	O
.	O
</s>
<s>
Now	O
,	O
again	O
the	O
processor	B-General_Concept
issues	O
a	O
read	O
Y	O
request	O
which	O
is	O
a	O
miss	O
in	O
both	O
L1	O
and	O
L2	O
.	O
</s>
<s>
An	O
example	O
of	O
non-inclusive	O
non-exclusive	O
cache	O
is	O
AMD	B-General_Concept
Opteron	I-General_Concept
with	O
non-inclusive	O
L3	O
cache	O
of	O
6	O
MB	O
(	O
shared	O
)	O
.	O
</s>
<s>
The	O
merit	O
of	O
inclusive	O
policy	O
is	O
that	O
,	O
in	O
parallel	B-Operating_System
systems	I-Operating_System
with	O
per-processor	O
private	O
cache	O
if	O
there	O
is	O
a	O
cache	O
miss	O
other	O
peer	O
caches	O
are	O
checked	O
for	O
the	O
block	O
.	O
</s>
