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-   -   physical address vs logical address (https://www.linuxquestions.org/questions/linux-virtualization-and-cloud-90/physical-address-vs-logical-address-4175541219/)

Funnix 04-30-2015 07:33 AM

physical address vs logical address
 
Hi

For me, the virtualized addresses are supposed to be smaller than (real) physical adrresses ?

So can someone explain me why I got these informations when I type in a TERM
"cat /proc/cpuinfo" :

address sizes : 36 bits physical, 48 bits virtual

(for additional informations :
vendor_id : GenuineIntel
cpu family : 6
model : 15
model name : Intel(R) Core(TM)2 Duo CPU T5250 @ 1.50GHz
stepping : 13
)


Thanks

smallpond 04-30-2015 01:37 PM

Why would you think that virtual addresses would be smaller than physical addresses? One reason virtual memory was invented was to be able to run programs that use a larger address space than the available physical memory. The active virtual address space of a process can include physical memory, swap, and file mmaps so the total can be very large.

jefro 04-30-2015 02:30 PM

http://www.linuxquestions.org/questi...puinfo-757456/

Ztcoracat 05-01-2015 12:00 AM

Quote:

Originally Posted by Funnix (Post 5355627)
Hi

For me, the virtualized addresses are supposed to be smaller than (real) physical adrresses ?

So can someone explain me why I got these informations when I type in a TERM
"cat /proc/cpuinfo" :

address sizes : 36 bits physical, 48 bits virtual

(for additional informations :
vendor_id : GenuineIntel
cpu family : 6
model : 15
model name : Intel(R) Core(TM)2 Duo CPU T5250 @ 1.50GHz
stepping : 13
)


Thanks

Are you trying to find out if your machine is 32-bit or 64-bit?

Running cat /proc/cpuinfo is for finding out what type of machine you have, what type of processors you have and other things.

Three basic types of addresses are recognized for addressing main storage: absolute, real, and virtual.
http://www-01.ibm.com/support/knowle...F0-1-0-2-1-0-0

Physical addresses refer to hardware addresses of physical memory.
Virtual addresses must be mapped into physical address. Here's the PDF to learn from.

http://www.google.com/url?sa=t&rct=j...geasDVeySF2gA&
bvm=bv.92189499,d.eXY

Funnix 05-07-2015 07:54 AM

Thank you for each answer
 
Ouua !

What great answers !!

Everythink is clear now !!

Thank you to the two answers received (each one helps to have a quite comprehensive view)

:)

Ztcoracat 05-07-2015 05:55 PM

Quote:

Originally Posted by Funnix (Post 5359109)
Ouua !

What great answers !!

Everythink is clear now !!

Thank you to the two answers received (each one helps to have a quite comprehensive view)

:)

If you are pleased with your answers and your problem is solved please explain the solution and mark your thread solved.


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