memory barrier in UP

[subin gangadharan]

Hi All,

I am reading about the barrier from linux kernel development.In this
books, he says
"On SMP kernels they are defined only as usual memory barriers.where
as on UP kernels they are
defined only as a compiler barrier"

Does this mean in UP, processor won't reorder the instructions ?

Could please give any idea on this.

-- 
With Regards
Subin Gangadharan

I am not afraid and I am also not afraid of being afraid.