Re: [rfc] direct IO submission and completion scalability issues

Nick Piggin
2008-02-03T11:58:18Z

On Sun, Feb 03, 2008 at 12:53:02PM +0200, Pekka Enberg wrote:
> Hi Nick,
>
> On Feb 3, 2008 11:52 AM, Nick Piggin <npiggin@suse.de> wrote:
> > +asmlinkage void smp_call_function_fast_interrupt(void)
> > +{
>
> [snip]
>
> > + while (!list_empty(&list)) {
> > + struct call_single_data *data;
> > +
> > + data = list_entry(list.next, struct call_single_data, list);
> > + list_del(&data->list);
> > +
> > + data->func(data->info);
> > + if (data->wait) {
> > + smp_mb();
> > + data->wait = 0;
>
> Why do we need smp_mb() here (maybe add a comment to keep
> Andrew/checkpatch happy)?

Yeah, definitely... it's just a really basic RFC, but I should get
into the habit of just doing it anyway.

Thanks,
Nick