On Tuesday 7 March 2006 21:09, David Howells wrote: > Alan Cox <[EMAIL PROTECTED]> 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.
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... > 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 Ciao, Duncan. - To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
