Os

[abhave]

I have a question on OS which is really bothering me...could you take the time to reply back on this email address...
>
> Lets say i have a 40GB hard disk. 1 GB is taken up by the OS. 30 GB go for
> the .exes and .dlls of the various installed programs. 5GB goes for data.
> Which means i have 4GB of disk space empty which could be potentially the
> max virtual memory size available on my computer. NOw my question is this
>
> 1. When a program is converted to a process to be run is it necessary that
> all its pages be in virtual memory at the time of execution? Can i have a
> 5GB program running on this machine with the OS handling page faults
between
> the original location where the program is stored on disk and the swap
space
> allocated in the same manner it handles page faults between main memory
and
> swap space? Of course i assume i have a processor gretaer than 32 bits so
> that the processor can generate addresses over 4GB.
>
> I am an engineering student and cant find the answer to this question in
any
> of the standard OS books. Help would be appreciated.
>
> Thanx
>
> Aditya
>

 

[TheHeadFL]

I am fairly sure that it has to be able to at least fit the entire executable portion into virtual memory. I do not believe there are any loaders which load from the original disk location when page faults occur.

The reason I think this is because I don't think a page table can contain references to files sitting off on the file system somewhere.