Hi Fan yang :) On Sat, Nov 3, 2012 at 1:04 PM, Fan Yang <lljyangfan@xxxxxxxxx> 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 _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
