Chapter 4 - DSpace at Waseda University

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Chapter 5
the data shows in Figure 5.15(a), there were 608 delays in Linux-rt-patched and 5,546 delays
in general-purpose Linux. In Figure 5.15(b), the number of delays in Linux-rt-patched was
1,607 and 1,620 in general-purpose Linux.
Figure 5.15: Result of experiment on Linux-RT and general Linux in 100μs. (a) Linux-
2.6.24-rt-patched and Linux-2.6.24-not_changed-softirq. (b) Linux-2.6.24-rt-patched and
Linux-2.6.24-changed-softirq.
Figure 5.16 shows the result of experiment on Linux-rt-patched and general-purpose Linux
in 1ms. By looking at data in Figure 5.16(a), there were 229 delays in Linux-rt-patched and
524 delays in general Linux. In Figure 5.15(b), data shows 289 delays in Linux-rt-patched
and 225 delays in general-purpose Linux. By comparing delay time of HRTimer to 100μs and
1ms, it is clear that the incidence of delay in 1ms is much low. Also, the result of Figure
5.16(b) shows that the result of solving delay problem of HRTimer by KAS is lower than
Figure 5.16(a). This is the result of experiment after modifying softriq, which is one of causes
of latency.