If I don't active the page mechanism

[Mulyadi Santosa]

Hi Fan yang :)

On Sat, Nov 3, 2012 at 1:04 PM, Fan Yang <lljyangfan at gmail.com> wrote:
> Hi Mulyadi Santosa
>     I think the OS can just use the segment mechanism to implement  the
> virtual memory management. When I look through the intel manual find that
> the Segment Descriptor have a member P, when the P is set this segment is
> located in the physical memory otherwise the segment is not located,but If
> this flag is clear, the processor generates a segment-not-present exception
> when a segment selector that points to the segment descriptor is loaded into
> a segment register. Just like the page mechanism we can just use the segment
> mechanism to manage the virtual memory. But it is Inefficiencies for
> swapping all segment from disk to memory and this way is no use in the
> Multiprocessor.

I can't comment much on this, however I agree that paging is more
efficient because you get page size granularity and all those features
offered by paging, versus simply using segment based approach where
you have to group memory area into continous ones.

So, I think, the biggest problem in modern memory management using
only segment based approach is tackling memory holes and lack of
delayed disk reading.


-- 
regards,

Mulyadi Santosa
Freelance Linux trainer and consultant

blog: the-hydra.blogspot.com
training: mulyaditraining.blogspot.com