Worksheet 12
64 hungry cats & Race Conditions Over Cold Broken Pizza
Bugcat joins his classmates (64 cats in total) at the CS department’s 導生聚. Ms. Kitty kindly orders a 16-inch Hawaiian pizza through Uber Eat.
Bugcat proposes to everyone:
“Hey! Let’s divide and conquer! We’ll cut the pizza into 64 slices so everyone gets one. That way, we finish eating 64x faster, before it gets cold!”
The cats cheer. Until… they actually start cutting.
Each slice must have at least one piece of ham and pineapple. Half the cats are measuring, the others are picking up dropped pineapples. By the time they finish slicing, the pizza became cold.
Bugcat meows: “Why isn’t parallel cutting/eating faster and we end up with cold broken pizza?”
Friend: “First, Uber Eat delivery is non-parallelizable. Second, so many cats cutting the pizza with shitty plastic knives is just a disaster.”
Another friend: “Amdahl’s Law says that even if 64 cats work in parallel, the non-parallelizable will dominate.”
“Not to mention the knife contention 🍴 !”
#Parallelized Hunger, #Paralyzed cats, #Zero Speedup Remember to open the English subtitle on Youtube: eLearn link of the video lecture If some people are fast and some people are slow, in the end, everyone is slow. I understand the following concepts:Video Lecture
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