<s>
LIRS	O
(	O
Low	O
Inter-reference	O
Recency	O
Set	O
)	O
is	O
a	O
page	B-General_Concept
replacement	I-General_Concept
algorithm	I-General_Concept
with	O
an	O
improved	O
performance	O
over	O
LRU	O
(	O
Least	O
Recently	O
Used	O
)	O
and	O
many	O
other	O
newer	O
replacement	O
algorithms	O
.	O
</s>
<s>
While	O
all	O
page	B-General_Concept
replacement	I-General_Concept
algorithms	I-General_Concept
rely	O
on	O
existence	O
of	O
reference	B-General_Concept
locality	I-General_Concept
to	O
function	O
,	O
a	O
major	O
difference	O
among	O
different	O
replacement	O
algorithms	O
is	O
on	O
how	O
this	O
locality	O
is	O
quantified	O
.	O
</s>
<s>
All	O
recently	O
accessed	O
pages	O
are	O
placed	O
in	O
a	O
FIFO	B-Operating_System
queue	O
called	O
the	O
LIRS	O
stack	O
(	O
stack	O
S	O
in	O
the	O
graph	O
)	O
,	O
and	O
all	O
resident	O
HIR	O
pages	O
are	O
also	O
placed	O
in	O
another	O
FIFO	B-Operating_System
queue	O
(	O
stack	O
Q	O
in	O
the	O
graph	O
)	O
.	O
</s>
<s>
LIRS	O
has	O
been	O
deployed	O
in	O
MySQL	B-Application
since	O
version	O
5.1	O
,	O
and	O
another	O
reference	O
by	O
.	O
</s>
<s>
It	O
is	O
also	O
adopted	O
in	O
Infinispan	B-Language
data	O
grid	O
platform	O
.	O
</s>
<s>
An	O
approximation	O
of	O
LIRS	O
,	O
CLOCK-Pro	O
,	O
is	O
adopted	O
in	O
NetBSD	B-Device
.	O
</s>
