A Work-Demand Analysis Compatible with Preemption-Aware Scheduling for Power-Aware Real-Time Tasks

Algorithm 1

IpWDA (PRA with ∗∗∗). Compute the available execution time and set the voltage/clock speed for 𝜏_𝛼.

(1) set 𝑢𝑑_𝑎∶=𝑝_𝛼,𝑒^{𝖤𝗑𝖼𝗁𝖺𝗇𝗀𝖾}∶=0 and 𝜏_{𝚊𝚜𝚢𝚗}∶=∅;

(2)  Compute 𝐻_𝛼(𝑡)∶=∑_{𝜏𝑘∈𝑇𝛼𝐴𝐶𝑇(𝑡)}𝑤^rem_𝑘(𝑡)+∑^𝛼−1_𝑖=1𝑢𝑑_𝛼−𝜀/𝑝_𝑖−(𝑡+𝜀)/𝑝_𝑖⋅𝑤_𝑖;

(3)  When a job 𝜏_𝛼 is activated, set 𝑤^rem_𝑘(𝑡)∶=𝑤_𝛼;

(4)  When a job 𝜏_𝛼 is completed or preempted, UpdateLoadInfo 𝑤^rem_𝛼(𝑡),𝑢𝑑_𝛼,𝐻_𝛼(𝑡);

(5)  When a job 𝜏_𝛼 is scheduled for execution

(6)   ^∗∗∗𝑒^{𝖤𝗑𝖼𝗁𝖺𝗇𝗀𝖾}∶=𝐏𝐑𝐀(𝑡,𝑇);          //get additional slack time

(7)  ∗∗∗ if   𝑟_𝛼=𝜏_{𝚊𝚜𝚢𝚗} and ℓ_𝛼^{𝚛𝚒𝚐𝚑𝚝}<𝑒^{𝖤𝗑𝖼𝗁𝖺𝗇𝗀𝖾}   then  𝜏_𝛼 has the lowest priority in readyQ(t);

(8)  𝑠𝑙𝑎𝑐𝑘_𝛼(𝑡)∶=  ClacSlackTime(𝑒^{𝖤𝗑𝖼𝗁𝖺𝗇𝗀𝖾});     //get slack time

(9)  set the clock frequency as 𝑓_𝑐𝑙𝑘∶=𝑤^rem_𝛼(𝑡)/𝑠𝑙𝑎𝑐𝑘_𝛼(𝑡)+𝑤^rem_𝛼(𝑡)⋅𝑓_𝚖𝚊𝚡;

(10)  𝑓_𝑐𝑙𝑘∶= max𝑓_𝑐𝑙𝑘,𝑓_𝐴𝐶𝐿;

(11)  Set the voltage accordingly;