<s>
A	O
free	B-General_Concept
list	I-General_Concept
(	O
or	O
freelist	B-General_Concept
)	O
is	O
a	O
data	O
structure	O
used	O
in	O
a	O
scheme	O
for	O
dynamic	B-General_Concept
memory	I-General_Concept
allocation	I-General_Concept
.	O
</s>
<s>
It	O
operates	O
by	O
connecting	O
unallocated	O
regions	O
of	O
memory	O
together	O
in	O
a	O
linked	B-Data_Structure
list	I-Data_Structure
,	O
using	O
the	O
first	O
word	O
of	O
each	O
unallocated	O
region	O
as	O
a	O
pointer	O
to	O
the	O
next	O
.	O
</s>
<s>
It	O
is	O
most	O
suitable	O
for	O
allocating	O
from	O
a	O
memory	B-General_Concept
pool	I-General_Concept
,	O
where	O
all	O
objects	O
have	O
the	O
same	O
size	O
.	O
</s>
<s>
Free	B-General_Concept
lists	I-General_Concept
make	O
the	O
allocation	O
and	O
deallocation	B-General_Concept
operations	O
very	O
simple	O
.	O
</s>
<s>
To	O
free	O
a	O
region	O
,	O
one	O
would	O
just	O
link	O
it	O
to	O
the	O
free	B-General_Concept
list	I-General_Concept
.	O
</s>
<s>
To	O
allocate	O
a	O
region	O
,	O
one	O
would	O
simply	O
remove	O
a	O
single	O
region	O
from	O
the	O
end	O
of	O
the	O
free	B-General_Concept
list	I-General_Concept
and	O
use	O
it	O
.	O
</s>
<s>
Free	B-General_Concept
lists	I-General_Concept
have	O
the	O
disadvantage	O
,	O
inherited	O
from	O
linked	B-Data_Structure
lists	I-Data_Structure
,	O
of	O
poor	O
locality	B-General_Concept
of	I-General_Concept
reference	I-General_Concept
and	O
so	O
poor	O
data	B-General_Concept
cache	I-General_Concept
utilization	O
,	O
and	O
they	O
do	O
not	O
automatically	O
consolidate	O
adjacent	O
regions	O
to	O
fulfill	O
allocation	O
requests	O
for	O
large	O
regions	O
,	O
unlike	O
the	O
buddy	B-General_Concept
allocation	I-General_Concept
system	I-General_Concept
.	O
</s>
<s>
Nevertheless	O
,	O
they	O
are	O
still	O
useful	O
in	O
a	O
variety	O
of	O
simple	O
applications	O
where	O
a	O
full-blown	O
memory	B-General_Concept
allocator	I-General_Concept
is	O
unnecessary	O
or	O
requires	O
too	O
much	O
overhead	O
.	O
</s>
<s>
The	O
OCaml	B-Language
runtime	O
uses	O
free	B-General_Concept
lists	I-General_Concept
to	O
satisfy	O
allocation	O
requests	O
,	O
as	O
does	O
RosAlloc	O
on	O
Android	O
Runtime	O
.	O
</s>
