Basics of Operating Sys

Mon, 21 Mar 2022 22:56:25 +0530

1. Operating System[OS]

it eleminates the need of contiguos memory allocation
have two main component and parts
component -> page number(p) and frame number(d)
parts + Logical address -> addres generated by the CPU {represented in bits} + Physical address -> physical location of a required data in a memory
In the process of accessing any data from memory, that will be done by accessing the memory location twice to remove this double accessing of the memory we use the TLB{Translation Lockaside Buffer}.
TLB –> It contains the page table entries that have been most recently used. IMAGE
it is a kind of cache memory resister of memory with there physical address
TLB stored the frequently used data for high speed accessing
It consist of two parts 4. key or tag :: like page number 5. value :: like frame number
It consist of few data that is { frequently/ recently used data}
If data not found in the TLB table then it will search in the page table for that data {TLB miss}
Advantages
Disadvantages
Terms 9. Hit Ratio{HR} –> successful search / total searches doen 10. Miss Ratio{MR} –> HR-total searches done 11. TLBT –> Time( complete TLB search ) 12. MAT –> TIme( time to acces memory ) 13. Effective Access Time 14. formula EAT = HR*( TLBT + MAT ) + MR*( TLBT + 2*MAT)