Am Donnerstag, 15. März 2007 09:16 schrieb Greg KH:
> On Wed, Mar 14, 2007 at 08:44:22PM +0100, Oliver Neukum wrote:
> > It is called in interrupt and uses no locking. What happens if the next
> > irq is processed on another cpu? Is that cpu guaranteed to see the updates
> > to the incremented variables?
>
> If you only have 1 interrupt urb, then you can't ever have multiple
> instances of this code running at the same time. Or am I missing
> something more obvious here?
I wasn't worrying about interrupts running at the same time, but after
each other on two CPUs. David has assured me that this is covered.
Nevertheless, this code has a slight race. If the counters are read twice
on two CPUs, the latter reader may see a lower count than the first reader.
As these counters must be monotonic this is a race. I'll fix it.
Regards
Oliver
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