Re: divorce CONFIG_X86_PAE from CONFIG_HIGHMEM64G

From: linux
Date: Tue Jun 12 2007 - 04:38:16 EST


Given that incomprehensible help texts are a bit of a pet peeve of mine
(I just last weekend figured out that you don't need to select an I2C
algorithm driver to have working I2c - I had thought it was a "one from
column A, one from column B" thing), let me take a crack...

PAE doubles the size of each page table entry, increasing
kernel memory consumption and slowing page table access.
However, it enables:
- Addressing more than 4G of physical RAM (CONFIG_HIGHMEM is
also required)
- Marking pages as readable but not executable using the NX
(no-execute) bit, which protects applications from stack
overflow attacks.
- Swap files or partitions larger than 64G each.
(Only needed with >4G RAM or very heavy tmpfs use.)

A kernel compiled with this option cannot boot on a processor
without PAE support. Enabling this also disables the
(expert use only) CONFIG_VMSPLIT_[23]G_OPT options.

Does that seem reasonably user-oriented?
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