<s>
In	O
computing	O
,	O
commit	B-General_Concept
charge	I-General_Concept
is	O
a	O
term	O
used	O
in	O
Microsoft	B-Application
Windows	I-Application
operating	I-Application
systems	I-Application
to	O
describe	O
the	O
total	O
amount	O
of	O
virtual	B-Architecture
memory	I-Architecture
of	O
all	O
processes	O
that	O
must	O
be	O
backed	O
by	O
either	O
physical	O
memory	O
or	O
the	O
page	B-Architecture
file	I-Architecture
.	O
</s>
<s>
Through	O
the	O
process	O
of	O
paging	B-Architecture
,	O
the	O
contents	O
of	O
this	O
virtual	B-Architecture
memory	I-Architecture
may	O
move	O
between	O
physical	O
memory	O
and	O
the	O
page	B-Architecture
file	I-Architecture
,	O
but	O
it	O
cannot	O
exceed	O
the	O
sum	O
of	O
sizes	O
of	O
those	O
two	O
.	O
</s>
<s>
As	O
a	O
percentage	O
,	O
commit	B-General_Concept
charge	I-General_Concept
is	O
the	O
utilization	O
of	O
this	O
limit	O
.	O
</s>
<s>
Virtual	B-Architecture
memory	I-Architecture
not	O
related	O
to	O
commit	B-General_Concept
charge	I-General_Concept
includes	O
virtual	B-Architecture
memory	I-Architecture
backed	O
by	O
files	O
and	O
all-zero	O
pages	O
backed	O
by	O
nothing	O
.	O
</s>
<s>
The	O
Windows	O
Task	O
Manager	O
utility	O
for	O
Windows	B-Application
XP	I-Application
and	O
Server	O
2003	O
,	O
in	O
its	O
Performance	O
tab	O
,	O
shows	O
three	O
counters	O
related	O
to	O
commit	B-General_Concept
charge	I-General_Concept
:	O
</s>
<s>
Total	O
is	O
the	O
amount	O
of	O
pagefile-backed	O
virtual	O
address	O
space	O
in	O
use	O
,	O
i.e.	O
,	O
the	O
current	O
commit	B-General_Concept
charge	I-General_Concept
.	O
</s>
<s>
This	O
is	O
composed	O
of	O
main	O
memory	O
(	O
RAM	B-Architecture
)	O
and	O
disk	O
(	O
pagefiles	B-Architecture
)	O
.	O
</s>
<s>
Limit	O
is	O
the	O
maximum	O
possible	O
value	O
for	O
Total	O
;	O
it	O
is	O
the	O
sum	O
of	O
the	O
current	O
pagefile	B-Architecture
size	O
plus	O
the	O
physical	O
memory	O
available	O
for	O
pageable	O
contents	O
(	O
this	O
excludes	O
RAM	B-Architecture
that	O
is	O
assigned	O
to	O
non-pageable	O
areas	O
)	O
.	O
</s>
<s>
Peak	O
is	O
the	O
highest	O
amount	O
that	O
the	O
total	O
commit	B-General_Concept
charge	I-General_Concept
has	O
reached	O
since	O
the	O
operating	B-General_Concept
system	I-General_Concept
was	O
last	O
started	O
.	O
</s>
<s>
The	O
program	O
Process	B-Application
Explorer	I-Application
reports	O
the	O
same	O
set	O
of	O
values	O
,	O
labeling	O
the	O
Total	O
as	O
Current	O
,	O
and	O
additionally	O
providing	O
percentages	O
of	O
Peak	O
and	O
Current	O
towards	O
the	O
Limit	O
value	O
.	O
</s>
<s>
The	O
commit	B-General_Concept
charge	I-General_Concept
increases	O
when	O
any	O
program	O
is	O
opened	O
and	O
used	O
,	O
and	O
goes	O
down	O
when	O
a	O
program	O
is	O
closed	O
.	O
</s>
<s>
It	O
will	O
also	O
change	O
when	O
already-running	O
programs	O
allocate	O
or	O
free	O
private	O
virtual	B-Architecture
memory	I-Architecture
;	O
for	O
example	O
,	O
with	O
the	O
VirtualAlloc	O
and	O
VirtualFree	O
APIs	O
.	O
</s>
<s>
In	O
the	O
Task	O
Manager	O
utility	O
under	O
Windows	B-Application
XP	I-Application
and	O
Windows	B-Application
Server	I-Application
2003	I-Application
,	O
the	O
graphical	O
displays	O
labeled	O
as	O
"	O
PF	O
usage	O
"	O
and	O
"	O
Page	B-Architecture
File	I-Architecture
Usage	I-Architecture
History	O
,	O
"	O
despite	O
their	O
labels	O
,	O
reflect	O
not	O
the	O
pagefile	B-Architecture
contents	O
but	O
the	O
total	O
(	O
or	O
current	O
)	O
commit	B-General_Concept
charge	I-General_Concept
.	O
</s>
<s>
These	O
do	O
not	O
show	O
how	O
much	O
has	O
actually	O
been	O
written	O
to	O
the	O
pagefile	B-Architecture
,	O
but	O
only	O
the	O
maximum	O
potential	O
pagefile	B-Architecture
usage	O
:	O
The	O
amount	O
of	O
pagefile	B-Architecture
that	O
would	O
be	O
used	O
if	O
all	O
current	O
contents	O
of	O
RAM	B-Architecture
had	O
to	O
be	O
removed	O
.	O
</s>
<s>
In	O
Windows	B-Application
2000	I-Application
and	O
Windows	B-Device
NT	I-Device
4.0	I-Device
,	O
these	O
same	O
displays	O
are	O
labeled	O
"	O
Mem	O
usage	O
"	O
but	O
again	O
actually	O
show	O
the	O
commit	B-General_Concept
charge	I-General_Concept
and	O
commit	O
limit	O
.	O
</s>
<s>
Similar	O
displays	O
in	O
the	O
Task	O
Manager	O
of	O
Windows	B-Application
Vista	I-Application
and	O
later	O
have	O
been	O
changed	O
to	O
reflect	O
usage	O
of	O
physical	O
memory	O
.	O
</s>
<s>
In	O
Task	O
Manager	O
's	O
"	O
Processes	O
"	O
display	O
,	O
each	O
process	O
's	O
contribution	O
to	O
the	O
"	O
total	O
commit	B-General_Concept
charge	I-General_Concept
"	O
is	O
shown	O
in	O
the	O
"	O
VM	O
size	O
"	O
column	O
in	O
Windows	B-Application
XP	I-Application
and	O
Server	O
2003	O
.	O
</s>
<s>
The	O
same	O
value	O
is	O
labeled	O
"	O
Commit	O
size	O
"	O
in	O
Windows	B-Application
Vista	I-Application
and	O
later	O
.	O
</s>
<s>
The	O
total	O
commit	B-General_Concept
charge	I-General_Concept
will	O
always	O
be	O
larger	O
than	O
the	O
sum	O
of	O
these	O
values	O
,	O
as	O
the	O
total	O
includes	O
system-wide	O
allocations	O
such	O
as	O
the	O
paged	O
pool	O
.	O
</s>
<s>
In	O
the	O
same	O
display	O
,	O
the	O
"	O
Mem	O
Usage	O
"	O
column	O
in	O
Windows	B-Application
XP	I-Application
and	O
Server	O
2003	O
,	O
or	O
the	O
"	O
Working	B-General_Concept
Set	I-General_Concept
(	O
Memory	O
)	O
"	O
column	O
in	O
Windows	B-Application
Vista	I-Application
and	O
later	O
,	O
shows	O
each	O
process	O
's	O
current	O
working	B-General_Concept
set	I-General_Concept
.	O
</s>
<s>
This	O
is	O
a	O
count	O
of	O
physical	O
memory	O
(	O
RAM	B-Architecture
)	O
rather	O
than	O
virtual	O
address	O
space	O
.	O
</s>
<s>
It	O
represents	O
the	O
subset	O
of	O
the	O
process	O
's	O
virtual	O
address	O
space	O
that	O
is	O
valid	O
,	O
meaning	O
that	O
it	O
can	O
be	O
referenced	O
without	O
incurring	O
a	O
page	B-General_Concept
fault	I-General_Concept
.	O
</s>
<s>
The	O
commit	B-General_Concept
charge	I-General_Concept
for	O
each	O
process	O
does	O
not	O
include	O
other	O
major	O
contributions	O
to	O
the	O
process	O
's	O
virtual	O
address	O
space	O
,	O
such	O
as	O
mapped	B-General_Concept
files	I-General_Concept
.	O
</s>
<s>
For	O
this	O
reason	O
,	O
the	O
process	O
's	O
working	B-General_Concept
set	I-General_Concept
(	O
the	O
portion	O
of	O
its	O
address	O
space	O
that	O
can	O
be	O
referenced	O
without	O
incurring	O
a	O
page	B-General_Concept
fault	I-General_Concept
)	O
may	O
be	O
larger	O
than	O
its	O
contribution	O
to	O
total	O
commit	B-General_Concept
charge	I-General_Concept
,	O
and	O
the	O
total	O
commit	B-General_Concept
charge	I-General_Concept
is	O
not	O
inclusive	O
of	O
the	O
total	O
memory	O
(	O
physical	O
or	O
virtual	O
)	O
actually	O
in	O
use	O
.	O
</s>
<s>
The	O
commit	O
limit	O
may	O
be	O
increased	O
by	O
either	O
creating	O
additional	O
pagefiles	B-Architecture
or	O
,	O
if	O
pagefile	B-Architecture
expansion	O
is	O
enabled	O
,	O
by	O
expanding	O
an	O
existing	O
one	O
.	O
</s>
<s>
The	O
operating	B-General_Concept
system	I-General_Concept
will	O
expand	O
the	O
pagefile	B-Architecture
automatically	O
,	O
if	O
possible	O
,	O
when	O
the	O
total	O
commit	B-General_Concept
charge	I-General_Concept
approaches	O
the	O
limit	O
.	O
</s>
<s>
If	O
the	O
system	O
ever	O
runs	O
completely	O
out	O
of	O
commit	B-General_Concept
charge	I-General_Concept
(	O
that	O
is	O
,	O
if	O
the	O
total	O
reaches	O
the	O
limit	O
)	O
,	O
a	O
popup	O
window	O
will	O
be	O
displayed	O
stating	O
that	O
"	O
The	O
system	O
is	O
out	O
of	O
virtual	B-Architecture
memory	I-Architecture
,	O
"	O
and	O
it	O
may	O
become	O
extremely	O
sluggish	O
or	O
even	O
nonresponsive	O
.	O
</s>
<s>
Closing	O
programs	O
(	O
if	O
the	O
user	O
is	O
still	O
able	O
to	O
do	O
so	O
at	O
this	O
point	O
)	O
decreases	O
the	O
total	O
commit	B-General_Concept
charge	I-General_Concept
and	O
may	O
thereby	O
free	O
up	O
the	O
system	O
.	O
</s>
