<s>
In	O
computing	O
and	O
communication	O
systems	O
,	O
a	O
work-conserving	B-General_Concept
scheduler	I-General_Concept
is	O
a	O
scheduler	B-Algorithm
that	O
always	O
tries	O
to	O
keep	O
the	O
scheduled	B-Algorithm
resource(s )	O
busy	O
,	O
if	O
there	O
are	O
submitted	O
jobs	O
ready	O
to	O
be	O
scheduled	B-Algorithm
.	O
</s>
<s>
In	O
contrast	O
,	O
a	O
non-work	O
conserving	O
scheduler	B-Algorithm
is	O
a	O
scheduler	B-Algorithm
that	O
,	O
in	O
some	O
cases	O
,	O
may	O
leave	O
the	O
scheduled	B-Algorithm
resource(s )	O
idle	B-Algorithm
despite	O
the	O
presence	O
of	O
jobs	O
ready	O
to	O
be	O
scheduled	B-Algorithm
.	O
</s>
<s>
For	O
example	O
,	O
when	O
dealing	O
with	O
networking	B-Application
and	I-Application
packet	I-Application
scheduling	I-Application
,	O
a	O
work-conserving	B-General_Concept
scheduler	I-General_Concept
leaves	O
the	O
channel	O
idle	B-Algorithm
only	O
when	O
there	O
are	O
no	O
packets	B-Protocol
to	O
transmit	O
,	O
whereas	O
a	O
non-work	O
conserving	O
scheduler	B-Algorithm
might	O
leave	O
the	O
channel	O
idle	B-Algorithm
with	O
packets	B-Protocol
still	O
pending	O
transmission	O
.	O
</s>
<s>
Similarly	O
,	O
when	O
referring	O
to	O
CPU	O
scheduling	B-Algorithm
,	O
i.e.	O
</s>
<s>
threads	B-Operating_System
or	O
processes	O
scheduled	B-Algorithm
over	O
one	O
or	O
more	O
available	O
processors	O
or	O
cores	O
,	O
a	O
work-conserving	B-General_Concept
scheduler	I-General_Concept
ensures	O
that	O
processors/cores	O
are	O
not	O
idle	B-Algorithm
if	O
there	O
are	O
processes/threads	O
ready	O
for	O
execution	B-General_Concept
.	O
</s>
<s>
Non-work	O
conserving	O
schedulers	B-Algorithm
are	O
sometimes	O
useful	O
to	O
enhance	O
predictability	O
and	O
reduce	O
termination	O
jitter	O
for	O
the	O
activities	O
carried	O
out	O
by	O
a	O
computing	O
and	O
communication	O
system	O
.	O
</s>
<s>
In	O
multi-processor	B-Operating_System
systems	O
they	O
're	O
useful	O
to	O
enhance	O
performance	O
in	O
some	O
scenarios	O
.	O
</s>
<s>
Sometimes	O
,	O
a	O
non-work	O
conserving	O
scheduler	B-Algorithm
may	O
be	O
useful	O
to	O
enhance	O
stability	O
of	O
a	O
system	O
;	O
For	O
example	O
,	O
a	O
process	O
scheduler	B-Algorithm
may	O
choose	O
to	O
keep	O
processes	O
off	O
of	O
the	O
run	O
queue	O
if	O
there	O
were	O
concern	O
that	O
the	O
sum	O
of	O
the	O
working	O
sets	O
of	O
all	O
of	O
the	O
runnable	O
processes	O
would	O
exceed	O
available	O
memory	O
and	O
lead	O
to	O
non-linear	O
page	O
thrashing	O
overhead	O
.	O
</s>
