2025/06/08 2

CH9-2 Uniprocessor Scheduling

Feedback์‹คํ–‰ ์‹œ๊ฐ„์ด ๊ธด ํ”„๋กœ์„ธ์Šค์˜ ์šฐ์„ ์ˆœ์œ„๋ฅผ ๋‚ฎ์ถ”๋Š” ๋ฐฉ์‹์‹คํ–‰ ์‹œ๊ฐ„์„ ์˜ˆ์ธกํ•˜์ง€ ์•Š๊ณ ๋„ ์‹คํ–‰ ์‹œ๊ฐ„์ด ์งง์€ ํ”„๋กœ์„ธ์Šคํ•œํ…Œ ์šฐ์„ ์ˆœ์œ„๋ฅผ ์ค„ ์ˆ˜ ์žˆ๋Š” ๋ฐฉ์‹starvation ๋ฐœ์ƒ ๊ฐ€๋Šฅ์„ฑ์ด ์žˆ๋‹ค q = 2^i - i๋Š” ํ์˜ ๋ฒˆํ˜ธ๋กœ, 0๋ฒˆ ํ๋Š” 2^0: 1์‹œ๊ฐ„ ์‹คํ–‰ ๊ฐ€๋Šฅ, 1๋ฒˆ ํ๋Š” 2^1: 2์‹œ๊ฐ„ ์‹คํ–‰ ๊ฐ€๋Šฅ,,, , n๋ฒˆ ํ๋Š” 2^n: n์‹œ๊ฐ„ ์‹คํ–‰ ๊ฐ€๋Šฅํ์˜ ๋ฒˆํ˜ธ๊ฐ€ ํด์ˆ˜๋ก ์‹คํ–‰ ๊ฐ€๋Šฅํ•œ ์‹œ๊ฐ„์ด ๊ธธ์–ด์ ธ์„œ starvation ๋ฐœ์ƒ ๊ฐ€๋Šฅ์„ฑ์„ ์ค„์ผ ์ˆ˜ ์žˆ๋‹ค. Multi-level Feedback Queue- ์—ฌ๋Ÿฌ ๊ฐœ์˜ ํ”ผ๋“œ๋ฐฑ ํ๋ฅผ ์‚ฌ์šฉํ•œ๋‹ค.0๋ฒˆ ํ์— ์žˆ๋Š” ํ”„๋กœ์„ธ์Šค: ์•„์ง ํ•œ ๋ฒˆ๋„ ์‹คํ–‰ํ•˜์ง€ ์•Š์Œ1๋ฒˆ ํ์— ์žˆ๋Š” ํ”„๋กœ์„ธ์Šค: 1์ดˆ ์ด์ƒ ์‹คํ–‰ํ•จ2๋ฒˆ ํ์— ์žˆ๋Š” ํ”„๋กœ์„ธ์Šค: 2์ดˆ ์ด์ƒ ์‹คํ–‰ํ•จ...n๋ฒˆ ํ์— ์žˆ๋Š” ํ”„๋กœ์„ธ์Šค: n์ดˆ ์ด์ƒ ..

CH9-1 Uniprocessor Scheduling

9์žฅ์—์„œ๋Š” ์‹œ์Šคํ…œ ์•ˆ์— CPU๊ฐ€ ํ•˜๋‚˜์ธ ์‹œ์Šคํ…œ์—์„œ์˜ CPU ๊ด€๋ฆฌ์— ๋Œ€ํ•œ ๋‚ด์šฉ์„ ๋‹ค๋ฃฌ๋‹ค. Aim of Scheduling: ์Šค์ผ€์ค„๋ง์˜ ๋ชฉ์ - Response time: ์‚ฌ์šฉ์ž๊ฐ€ ์‹œ์Šคํ…œ์— ์ž‘์—…์„ ์š”์ฒญํ•œ ์ˆœ๊ฐ„๋ถ€ํ„ฐ ์‘๋‹ต์„ ๋ฐ›์„ ๋•Œ๊นŒ์ง€ ๊ฑธ๋ฆฌ๋Š” ์‹œ๊ฐ„- Throughput: ๋‹จ์œ„ ์‹œ๊ฐ„๋‹น ์‹œ์Šคํ…œ์ด ์™„๋ฃŒํ•˜๋Š” ์ž‘์—…์˜ ์–‘- Processor efficiency: ์ „์ฒด ์‹œ๊ฐ„ ์ค‘ CPU๊ฐ€ ์‹ค์ œ๋กœ ์ž‘์—…์„ ์ฒ˜๋ฆฌํ•˜๋ฉฐ ๋ฐ”์˜๊ฒŒ ์‹คํ–‰๋œ ์‹œ๊ฐ„์˜ ๋น„์œจ- Fairness: ๋ชจ๋“  ํ”„๋กœ์„ธ์Šค๊ฐ€ CPU ์ž์›์„ ๊ณตํ‰ํ•˜๊ฒŒ ํ• ๋‹น๋ฐ›๋„๋ก ๋ณด์žฅํ•˜๋Š” ๊ฒƒ์„ ๋ชฉํ‘œ๋กœ ํ•œ๋‹ค. Types of Scheduling1. Long-term Scheduling- ์ƒˆ๋กœ์šด ํ”„๋กœ์„ธ์Šค๊ฐ€ ์ƒ์„ฑ๋  ๋•Œ ์–ด๋–ค ํ”„๋กœ์„ธ์Šค๋ฅผ ๋ ˆ๋”” ํ์— ๋„ฃ์„์ง€๋ฅผ ๊ฒฐ์ •- batch job์„ ์œ„ํ•œ ์Šค์ผ€์ค„๋ง์ด๋‹ค.2. M..