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Re: difference between virtual address and linear address

On Mon, 22 Jan 2001, kamesh jayachandran wrote:

> Hai,
> It may be a trivial question.Now I got confused by the two terms virtual 
> address and linear address.Can anyone throw some light on this.
> Thanks in advance
> kamesh jayachandran

hai kamesh 

a'm trying to differentiate between these two terms 

whenever a process executes a program it reads a instruction from mem and
executes it, for this it needs memory addresses 

in A virtual memory system all of the addresses used by process r virtual
addresses not the physical (linear ) addresses , these virtual addresses
are converted in to linear addresses by processor based on information
held in a set of tables maintained by os 

v-address is good as it provides a unified view of memory (ie the process
sees that it has got memory in sequence of contigous memory locations
)while physicaly os allocates pages at different mem locations and maps
the virtual address transparently

second major advantage of v-addressing is the process has got big mem on
his disposal ( bigger then main mem ) 

for more details see OS book by Galvin and others ( big dianasoures book )


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