<s>
A	O
write	B-General_Concept
buffer	I-General_Concept
is	O
a	O
type	O
of	O
data	B-General_Concept
buffer	I-General_Concept
that	O
can	O
be	O
used	O
to	O
hold	O
data	O
being	O
written	O
from	O
the	O
cache	O
to	O
main	O
memory	O
or	O
to	O
the	O
next	O
cache	O
in	O
the	O
memory	B-General_Concept
hierarchy	I-General_Concept
to	O
improve	O
performance	O
and	O
reduce	O
latency	O
.	O
</s>
<s>
It	O
is	O
used	O
in	O
certain	O
CPU	B-General_Concept
cache	I-General_Concept
architectures	O
like	O
Intel	O
's	O
x86	O
and	O
AMD64	O
.	O
</s>
<s>
In	O
multi-core	O
systems	O
,	O
write	B-General_Concept
buffers	I-General_Concept
destroy	O
sequential	B-General_Concept
consistency	I-General_Concept
.	O
</s>
<s>
Some	O
software	O
disciplines	O
,	O
like	O
C11	O
's	O
data-race-freedom	O
,	O
are	O
sufficient	O
to	O
regain	O
a	O
sequentially	B-General_Concept
consistent	I-General_Concept
view	O
of	O
memory	O
.	O
</s>
<s>
Use	O
of	O
a	O
write	B-General_Concept
buffer	I-General_Concept
in	O
this	O
manner	O
frees	O
the	O
cache	O
to	O
service	O
read	O
requests	O
while	O
the	O
write	O
is	O
taking	O
place	O
.	O
</s>
<s>
When	O
the	O
write	B-General_Concept
buffer	I-General_Concept
is	O
full	O
(	O
i.e.	O
</s>
<s>
all	O
buffer	B-General_Concept
entries	O
are	O
occupied	O
)	O
,	O
subsequent	O
writes	O
still	O
have	O
to	O
wait	O
until	O
slots	O
are	O
freed	O
.	O
</s>
<s>
Subsequent	O
reads	O
could	O
be	O
served	O
from	O
the	O
write	B-General_Concept
buffer	I-General_Concept
.	O
</s>
<s>
To	O
further	O
mitigate	O
this	O
stall	O
,	O
one	O
optimization	O
called	O
write	B-General_Concept
buffer	I-General_Concept
merge	O
may	O
be	O
implemented	O
.	O
</s>
<s>
Write	B-General_Concept
buffer	I-General_Concept
merge	O
combines	B-Architecture
writes	I-Architecture
that	O
have	O
consecutive	O
destination	O
addresses	O
into	O
one	O
buffer	B-General_Concept
entry	O
.	O
</s>
<s>
A	O
victim	B-General_Concept
buffer	I-General_Concept
is	O
a	O
type	O
of	O
write	B-General_Concept
buffer	I-General_Concept
that	O
stores	O
dirty	O
evicted	O
lines	O
in	O
write-back	O
caches	O
so	O
that	O
they	O
get	O
written	O
back	O
to	O
main	O
memory	O
.	O
</s>
<s>
Besides	O
reducing	O
pipeline	O
stall	O
by	O
not	O
waiting	O
for	O
dirty	O
lines	O
to	O
write	O
back	O
as	O
a	O
simple	O
write	B-General_Concept
buffer	I-General_Concept
does	O
,	O
a	O
victim	B-General_Concept
buffer	I-General_Concept
may	O
also	O
serve	O
as	O
a	O
temporary	O
backup	O
storage	O
when	O
subsequent	O
cache	O
accesses	O
exhibit	O
locality	B-General_Concept
,	O
requesting	O
those	O
recently	O
evicted	O
lines	O
,	O
which	O
are	O
still	O
in	O
the	O
victim	B-General_Concept
buffer	I-General_Concept
.	O
</s>
<s>
The	O
store	O
buffer	B-General_Concept
was	O
invented	O
by	O
IBM	O
during	O
Project	O
ACS	O
between	O
1964	O
and	O
1968	O
,	O
but	O
it	O
was	O
first	O
implemented	O
in	O
commercial	O
products	O
in	O
the	O
1990s	O
.	O
</s>
