Advantages of segmentation over paging?
Advantages of segmentation over paging:
Speed. Reloading segment registers to change address spaces is
much faster than switching page tables.
Segment descriptor tables consume less memory than page
tables.
x86 page table entries do not have an 'Executable' bit. With
segmentation, you can make a region of memory executable (code) or
not (data).
Segment size can be byte-granular (size 1 byte to 1Meg in units
of 1 byte); pages are always page-granular (size 4K to 4Gig in
units of 4K). Segmentation lets you make the segment as large as
necessary, with no excess (there is no internal fragmentation).