[PATCH] Document Linux's memory barriers

[Paul Mackerras]

Duncan Sands writes:

> On UP you at least need compiler barriers, right?  You're in trouble if you think
> you are writing in a certain order, and expect to see the same order from an
> interrupt handler, but the compiler decided to rearrange the order of the writes...

I'd be interested to know what the C standard says about whether the
compiler can reorder writes that may be visible to a signal handler.
An interrupt handler in the kernel is logically equivalent to a signal
handler in normal C code.

Surely there are some C language lawyers on one of the lists that this
thread is going to?

Paul.