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memorylinux-kernelkernelstorage
geek
geek

Reputation: 2847

physical storage of the kernel data

I have some question about physical storage of the kernel data in Linux, I know that the upper 1 GB of the VIRTUAL memory of each process points to the same PHYSICAL location, but

  1. this piece of the data has to be contigious in PHYSICAL media as in VIRTUAL MEMORY?
  2. does kernel data will take ONLY 1 GB of the PHYSICAL memory?
  3. can some pages of the kernel data be swapped to the disk (for example page tables, page global directory is always in physical memory and can't be swapped to disk as I understand)

Upvotes: 0

Views: 156

Answers (1)

blaze
blaze

Reputation: 4364

  1. First GB of physical memory mapped to high GB of virtual addresses linearly. But kernel can modify this mappings.
  2. Yes, it is.
  3. No, linux kernel is not swappable. Only user processes memory can be swapped out.

Note that this is only valid for 32-bit systems. Mappings on 64-bit systems are different.

Upvotes: 1

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