High-Performance Embedded Computing

4.2 Real-Time Process Scheduling 239

Jejurikar et al. [Jej04] used procrastination scheduling to maximize idle peri-

ods. They modeled the power consumption of a processor as three components:

(EQ 4-15)

the dynamic power, the static power consumption, and on-state power. On-state

power is consumed by the clock, I/O devices, and other peripheral circuitry.

They compute the minimum breakeven time for a shutdown as

. (EQ 4-16)

Given a set of processes, they use EDF scheduling with the deadline equal to

the period and a known worst-case execution time. When a new task arrives,

they do not wake up the processor immediately; instead, they wait for a procras-

tination timer to expire before waking up the processor and starting the highest-

priority task (usi ...