Information Technology Reference
In-Depth Information
30000
ET-only
TT-only (
SP
=10
,LSP
)
HyRV (
SP
=10
,LSP,Cx→y
= 100
)
HyRV (
25000
SP
=10
,LSP,Cx→y
= 150
)
TT-only (
SP
=20
,LSP
)
20000
HyRV (
SP
=20
,LSP,Cx→y
= 100
)
HyRV (
SP
=20
,LSP,Cx→y
= 150
)
15000
10000
5000
0
C
ET
=
C
TT
= 100
C
ET
=
C
TT
= 150
C
ET
=
C
TT
= 250
Monitoring Cost
Fig. 8.
Monitoring overhead of
insertsort
for three monitoring modes under all cost
configurations
120000
ET-only
TT-only (
SP
=10
,LSP
)
HyRV (
SP
=10
,LSP,Cx→y
= 100
)
HyRV (
SP
=10
,LSP,Cx→y
= 150
)
TT-only (
SP
=20
,LSP
)
HyRV (
SP
=20
,LSP,Cx→y
= 100
)
HyRV (
SP
=20
,LSP,Cx→y
= 150
)
100000
80000
60000
40000
20000
0
C
ET
=
C
TT
= 100
C
ET
=
C
TT
= 150
C
ET
=
C
TT
= 250
Monitoring Cost
Fig. 9.
Monitoring overhead of
fir
for three monitoring modes under all cost config-
urations
and
matmult
) is that the programs have dense and evenly distributed critical
instructions in their respective CFG. This makes the use of TT mode a suitable
choice to monitor this class of programs. Figure 8 shows the overhead of monitor-
ing
insertsort
with three monitoring modes (ET-only, TT-only, and hybrid)
for all cost configurations. The rest of the programs in this class also exhibit
similar monitoring overhead patterns. From Figure 8, one can observe that the
corresponding ILP model correctly detects the even distribution of events and
the solution suggests monitoring exclusively in TT mode as its solution for all
cost configurations. Another observation in these experiments is that the num-
ber of redundant samples for these programs is either zero or close to zero. The
low number of redundant samples again validates the choice of monitoring these
programs using the time-triggered method.
Hybrid Monitor with Mixed Behavior.
The program representing this class
(i.e.
fir
with CFG of the size 24 vertices and 27 arcs) does not clearly belong
to the previous two classes. The number of redundant samples for this program
reduces by a factor of six as the sampling period increases from 10
×
LSP
to
20
×
LSP
. This brings the overheads of ET and TT modes to a comparable