<s>
Timer	B-Operating_System
coalescing	I-Operating_System
is	O
a	O
computer	O
system	O
energy-saving	O
technique	O
that	O
reduces	O
central	B-General_Concept
processing	I-General_Concept
unit	I-General_Concept
(	O
CPU	O
)	O
power	O
consumption	O
by	O
reducing	O
the	O
precision	O
of	O
software	O
timers	O
used	O
for	O
synchronization	O
of	O
process	O
wake-ups	O
,	O
minimizing	O
the	O
number	O
of	O
times	O
the	O
CPU	O
is	O
forced	O
to	O
perform	O
the	O
relatively	O
power-costly	O
operation	O
of	O
entering	O
and	O
exiting	O
idle	B-Algorithm
states	I-Algorithm
.	O
</s>
<s>
The	O
Linux	B-Operating_System
kernel	I-Operating_System
gained	O
support	O
for	O
deferrable	O
timers	O
in	O
2.6.22	O
,	O
and	O
controllable	O
"	O
timer	O
slack	O
"	O
for	O
threads	B-Operating_System
in	O
2.6.28	O
allowing	O
timer	B-Operating_System
coalescing	I-Operating_System
.	O
</s>
<s>
Timer	B-Operating_System
coalescing	I-Operating_System
has	O
been	O
a	O
feature	O
of	O
Microsoft	B-Application
Windows	I-Application
from	O
Windows	B-Device
7	I-Device
onward	O
.	O
</s>
<s>
Apple	O
's	O
XNU	B-Operating_System
kernel	I-Operating_System
based	O
OS	B-Operating_System
X	I-Operating_System
gained	O
support	O
as	O
of	O
OS	B-Operating_System
X	I-Operating_System
Mavericks	I-Operating_System
.	O
</s>
<s>
FreeBSD	B-Operating_System
supports	O
it	O
since	O
September	O
2010	O
.	O
</s>
