[PATCH] Document Linux's memory barriers

David Howells dhowells at redhat.com
Wed Mar 8 07:09:07 EST 2006


Alan Cox <alan at lxorguk.ukuu.org.uk> wrote:

> Better meaningful example would be barriers versus an IRQ handler. Which
> leads nicely onto section 2

Yes, except that I can't think of one that's feasible that doesn't have to do
with I/O - which isn't a problem if you are using the proper accessor
functions.

Such an example has to involve more than one CPU, because you don't tend to
get memory/memory ordering problems on UP.

The obvious one might be circular buffers, except there's no problem there
provided you have a memory barrier between accessing the buffer and updating
your pointer into it.

David



More information about the Linuxppc64-dev mailing list