Review your favorite Linux distribution.
Go Back > Forums > Linux Forums > Linux - Newbie
User Name
Linux - Newbie This Linux forum is for members that are new to Linux.
Just starting out and have a question? If it is not in the man pages or the how-to's this is the place!


  Search this Thread
Old 12-17-2006, 11:21 AM   #1
LQ Newbie
Registered: Sep 2004
Location: India
Posts: 1

Rep: Reputation: 0
Unhappy Memory management ??????

My doubt is regarding 32 bit systems.

And Kernel will take around 1 GB of memory and this is common to all processes. Each process will map this to their starting wirtual addresses.

My doubt is, Is this 4 GB limit is for one process or all the processes together in the system.

As far as I know wiht Virtual Memory management one can address maximum of 4 GB(32 bit). It ok if all processes can address 4 GB combined.
Is it that each process is allocated a separate address inside a single 4 GB adress space


If each process can address 4 Gb then how is it managed.
Does any body have any clue

Old 12-17-2006, 12:18 PM   #2
Senior Member
Registered: May 2004
Location: In the DC 'burbs
Distribution: Arch, Scientific Linux, Debian, Ubuntu
Posts: 4,289

Rep: Reputation: 378Reputation: 378Reputation: 378Reputation: 378
Each process has a 4 GB virtual memory space. As you say, the top 1 GB (usually) of the address space is reserved for the kernel and common to all processes, but the other 3 GB is exclusive to the process (excluding consideration like shared memory here). The total amount of memory used by all processes may exceed 4 GB, but this would require the use of swap space as a 32 bit kernel can only access 4 GB of physical memory (remember that the user and kernel memory that I talk about above refer to virtual addresses, which are translated to physical addresses via the MMU on the CPU using rules given by the kernel). Therefore, all the processes in the system may use more memory than the physical memory installed, but no more than physical memory plus swap space (or any other backing store).


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
memory management navaladi Mandriva 2 02-18-2005 07:47 AM
memory management exigent Linux - General 1 08-17-2003 09:28 PM
memory management? snow Linux - Software 7 02-12-2003 02:57 PM
Memory Management hhegab Linux - General 3 08-07-2002 11:20 PM
Memory Management mrsolo Linux - General 7 06-26-2002 01:55 AM > Forums > Linux Forums > Linux - Newbie

All times are GMT -5. The time now is 09:39 PM.

Main Menu
Write for LQ is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration