Hi Mulyadi, Thanks for the answer. On Mon, Dec 12, 2011 at 11:16 AM, Mulyadi Santosa <mulyadi.santosa@gmail.com> wrote:
Hi...
On Mon, Dec 12, 2011 at 01:11, subin gangadharan <subingangadharan@gmail.com> wrote:
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 ?
In some arch like Alpha, loosely reordering even in UP could happen at any time. But in x86 UP, IIRC there's only strict re-ordering, meaning that every read is always fetching latest write etc.
In that case (ALPHA), is compiler barrier sufficient enough to prevent the re ordering done by the processor. What I was thinking,compiler barrier is to instruct the compiler to not do any re ordering. Please correct me if I am wrong.
-- regards,
Mulyadi Santosa Freelance Linux trainer and consultant
blog: the-hydra.blogspot.com training: mulyaditraining.blogspot.com
-- With Regards Subin Gangadharan I am not afraid and I am also not afraid of being afraid.