Qhov Tseem Ceeb Qhov txawv - Preemptive vs Nonpreemptive Teem sijhawm hauv OS
Ib txheej txheem yog ib qho kev pabcuam hauv kev ua tiav. Lub computer yuav tsum ua ntau yam haujlwm tib lub sijhawm. Yog li, CPU yuav tsum tau txais cov txheej txheem thiab ua tiav lawv. Qee lub sij hawm nws yog ib qho tsim nyog los ua qee cov txheej txheem dua li lwm cov txheej txheem. Thaum lub sijhawm ntawd, cov txheej txheem khiav tau cuam tshuam, thiab CPU tau faib rau cov txheej txheem tshiab. Tom qab ua tiav txoj haujlwm, CPU tau faib rov qab rau cov txheej txheem dhau los. Lub sij hawm raws li qhov no mechanism yog hu ua preemptive scheduling. Yog tias cov txheej txheem khiav, tsis tuaj yeem cuam tshuam thiab nws yog qhov yuav tsum tau ua kom tiav cov txheej txheem khiav, ces nws yog hu ua nonpreemptive scheduling. Kab lus no tham txog qhov sib txawv ntawm kev teem caij preemptive thiab nonpreemptive nyob rau hauv lub operating system. Preemptive scheduling yog cov txheej txheem teem sij hawm los ntawm cov txheej txheem uas tuaj yeem cuam tshuam los ntawm lwm cov txheej txheem hauv nruab nrab ntawm nws qhov kev ua tiav. Kev teem caij tsis pub dhau yog cov txheej txheem teem caij ua haujlwm los ntawm qhov txheej txheem pib ua tiav tsuas yog tom qab cov txheej txheem dhau los xaus. Qhov ntawd yog qhov sib txawv tseem ceeb ntawm Preemptive thiab Nonpreemptive Scheduling hauv OS.
Lub Sijhawm Preemptive hauv OS yog dab tsi?
Round Robin Teem sijhawm yog ib qho piv txwv ntawm kev teem caij ua ntej. Txhua txheej txheem tau txais me me ntawm lub sijhawm CPU. Nws feem ntau yog 10 mus rau 100 milliseconds. Cov ntaub ntawv me me no tseem hu ua lub sijhawm quantum. Tom qab lub sijhawm no tau dhau mus, cov txheej txheem yog preempted thiab ntxiv rau qhov kawg ntawm qhov npaj tos. Xav tias muaj 4 txheej txheem xws li P1, P2, P3 thiab P4. CPU tawg lub sij hawm nyob rau hauv milliseconds yog raws li nram no. Lub sijhawm quantum yog 20.
Daim duab 01: Piv txwv ntawm Round Robin Scheduling
Cov txheej txheem P1 ua tiav txog 20. Muaj 33ms sab laug. Tom qab ntawd lub P2 ua haujlwm. Raws li lub sij hawm quantum yog 20 thiab lub sij hawm xav tau P2 yog 17ms, P2 yuav ua rau 17ms. Yog li, cov txheej txheem P2 tiav. Tom qab ntawd muab lub sijhawm rau P3. Nws yuav ua rau 20ms. Tus so yog 48ms. Tom qab ntawd lub P4 yuav ua rau 20ms. Nws muaj 4ms los ua kom tiav tag nrho cov txheej txheem. Ib zaug ntxiv, P1 yuav ua rau 20ms. Nws muaj lwm 13ms los ua kom tiav cov txheej txheem. Kev hloov pauv tau muab rau P3. Nws yuav ua rau 20ms, thiab nws muaj 28ms ntxiv kom tiav tag nrho. P4 ua haujlwm. Nws tsuas muaj 4ms. Yog li ntawd, P4 ua tiav qhov kev ua tiav. P2 thiab P4 twb tiav lawm. Cov txheej txheem ntxiv yog P1 thiab P3. Lub caij nyoog yog muab rau P3. Nws muaj 13ms ua kom tiav, yog li nws ua tiav. Tam sim no tsuas yog cov txheej txheem tseem tshuav yog P3. Nws muaj 28ms kom tiav. Yog li P3 yuav khiav rau 20ms. Tus so yog 8ms. Tag nrho lwm cov txheej txheem tau ua tiav tiav. Yog li ntawd, dua li ntawm 8ms ntawm P3 yuav ua tiav. Ib yam li ntawd, txhua txoj kev tau txais txoj hauv kev los ua.
Lub Sijhawm Tsis Txaus Siab Hauv OS yog dab tsi?
Thawj Tuaj Ua Ntej Ua Ntej (FCFS) lub sijhawm teem sijhawm tuaj yeem coj los ua piv txwv ntawm kev teem sijhawm uas tsis yog preemptive. Cov txheej txheem uas thov thawj zaug yog faib rau CPU ua ntej. Qhov kev teem caij no tau yooj yim tswj hwm los ntawm Thawj Hauv Thawj Tawm (FIFO) kab. Yog tias muaj cov txheej txheem tuaj raws li P1, P2 thiab P3, ces lub sijhawm yog thawj zaug rau P1. Tom qab ua tiav, P2 yuav ua tiav. Thaum P2 ua tiav, P3 yuav ua tiav. Xav tias muaj 3 txheej txheem li P1, P2 thiab P3 nrog CPU tawg lub sij hawm hauv milliseconds raws li hauv qab no.
Daim duab 02: Piv txwv ntawm FCFS Teem sijhawm
Raws li saum toj no, P1 yuav ua tiav. Thaum nws ua tiav, cov txheej txheem P2 raug tua rau 3ms. Tam sim no cov txheej txheem ntxiv yog P3. Ces nws yuav ua. Lub sijhawm tos rau P1 yog xoom. Cov txheej txheem P2 yuav tsum tau tos 24ms, thiab cov txheej txheem P3 yuav tsum tau tos 27ms. Yog tias cov txheej txheem tuaj txog hauv kev txiav txim P2, P3 thiab P1 ces P2 yuav ua tiav ua ntej. Tom ntej no P3 yuav ua kom tiav, thiab thaum kawg, P1 yuav ua tiav.
Dab tsi yog qhov zoo sib xws ntawm Preemptive thiab Nonpreemptive Scheduling hauv OS?
Ob qho tib si Preemptive thiab Nonpreemptive Teem sijhawm hauv OS yog cov txheej txheem los teem sijhawm cov txheej txheem hauv computer
Qhov txawv ntawm Preemptive thiab Nonpreemptive Scheduling hauv OS?
Preemptive vs Nonpreemtive Teem sijhawm hauv OS |
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| Lub sijhawm teem sijhawm ua ntej yog txheej txheem teem sijhawm los ntawm cov txheej txheem tuaj yeem cuam tshuam los ntawm lwm cov txheej txheem hauv nruab nrab ntawm nws qhov kev ua tiav. | Lub sijhawm teem sijhawm tsis yog qhov kev teem sijhawm yog txheej txheem teem sijhawm los ntawm ib txheej txheem pib ua tiav tsuas yog tom qab cov txheej txheem dhau los xaus. |
| txheej txheem cuam tshuam | |
| Hauv kev teem sijhawm ua ntej, cov txheej txheem tuaj yeem cuam tshuam. | Nyob rau hauv lub sijhawm teem sijhawm, cov txheej txheem tuaj yeem cuam tshuam. |
| CPU siv | |
| Hauv kev teem caij ua ntej, kev siv CPU yog siab dua li qhov tsis tau teem caij. | Nyob rau hauv lub sijhawm teem sijhawm tsis tau teem sijhawm, kev siv CPU tsawg kawg yog piv rau kev teem caij ua ntej. |
| Flexibility | |
| Kev teem caij ua ntej yog hloov tau. | Nyob rau lub sijhawm teem tseg tsis hloov pauv. |
Summary – Preemptive vs Nonpreemptive Scheduling in OS
Muaj ntau cov txheej txheem khiav ntawm lub computer. Thaum txhua tus txheej txheem ua tiav, CPU tau faib rau cov txheej txheem tshwj xeeb. Qee zaum, nws yog ib qho tsim nyog yuav tsum tau tso tseg qhov kev ua tiav ntawm cov txheej txheem tam sim no thiab muab qhov tseem ceeb rau lwm txoj kev. Cov txheej txheem teem sij hawm cov txheej txheem tuaj yeem ua ntej lossis tsis ua ntej. Preemptive scheduling yog tus txheej txheem teem sijhawm mechanism uas cov txheej txheem tuaj yeem cuam tshuam los ntawm lwm cov txheej txheem hauv nruab nrab ntawm nws qhov kev ua tiav. Kev teem caij tsis pub dhau yog cov txheej txheem teem caij ua haujlwm txawm tias ib qho txheej txheem pib ua tiav tsuas yog tom qab cov txheej txheem dhau los xaus. Qhov no yog qhov txawv ntawm Preemptive thiab Nonpreemptive Scheduling hauv OS.
Download the PDF of Preemptive vs Nonpreemptive Scheduling in OS
Koj tuaj yeem rub tawm PDF version ntawm kab lus no thiab siv nws rau offline hom phiaj raws li daim ntawv ceeb toom. Thov rub tawm PDF version ntawm no: Qhov txawv ntawm Preemptive thiab Nonpreemptive Scheduling hauv OS
