On Tue, Aug 27, 2002 at 01:52:13PM -0400, anton wilson wrote:
> Does a volatile variable never reside in cache?
It is my understanding of volatile that it will force the compiler to
never rely on a register for the value -- it must always fetch from
memory. The memory fetches will still go through cache. I think it is up
to the hardware to ensure that cache is coherent across all CPUs.
> struct _test{
> volatile x;
> char arr[1024];
> }test;
>
> if I use x, will the first part
> of the arr string get read into cache or not?
I'd expect this to be highly dependant upon where the struct is located
in memory; there are probably places in memory where the first 28 bytes
f the array would be cached, and other places in memory where none of
the array would be cached. And, as always, this is highly platform
dependant. :)
--
It seems the power has been robbed from the founding fathers and is now
firmly in the hand of the funding fathers -- Rik van Riel
Attachment:
pgp00154.pgp
Description: PGP signature
