Re: [PATCH] Document Linux's memory barriers
From: Alan Cox
Date: Tue Mar 07 2006 - 19:30:57 EST
On Maw, 2006-03-07 at 20:09 +0000, David Howells wrote:
> Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> 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.
We get them off bus masters for one and you can construct silly versions
of the other.
There are several kernel instances of
while(*ptr != HAVE_RESPONDED && time_before(jiffies, timeout))
rmb();
where we wait for hardware to bus master respond when it is fast and
doesn't IRQ.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/