* Wanpeng Li <[email protected]> wrote:
> Hi Ingo,
> On Tue, Mar 17, 2015 at 09:06:13AM +0100, Ingo Molnar wrote:
> >
> >* Wanpeng Li <[email protected]> wrote:
> >
> >> Hi Ingo,
> >> On Mon, Mar 16, 2015 at 04:01:02PM +0100, Ingo Molnar wrote:
> >> >> +
> >> >> + /*
> >> >> + * If cannot preempt any rq, fallback to pick
> >> >> any
> >> >> + * online cpu.
> >> >
> >> >s/If cannot/If we cannot
> >> >s/fallback/fall back
> >>
> >> Will do.
> >>
> >> >
> >> >> + */
> >> >> + fallback = true;
> >> >> + cpu = cpumask_any_and(cpu_active_mask,
> >> >> + tsk_cpus_allowed(p));
> >> >
> >> >shouldn't be on separate lines - but this is also a sign that the guts
> >>
> >> Otherwise there is a "WARNING: line over 80 characters".
> >
> >Yes, but did your reaction to that tool's warning improve the code? I
> >don't think so. If do what I suggested and reduce indentation a bit,
> >you'll fix the warning _and_ improve the code. Win-win.
>
> Cool, will do.
>
> >
> >> > of this new code should be in a helper function, not inside
> >> > several layers of branches.
> >>
> >> Do you mean the whole patch should be in a helper function?
> >
> >Probably.
>
> Will do.
>
> >
> >> >> + if (cpu >= nr_cpu_ids) {
> >> >> + if (dl_bandwidth_enabled()) {
> >> >> + /*
> >> >> + * Fail to find any suitable
> >> >> cpu.
> >> >> + * The task will never come
> >> >> back!
> >> >> + */
> >> >> + WARN_ON(1);
> >> >
> >> > Can this condition happen to users with a non-buggy kernel?
> >>
> >> What do you prefer? ;-)
> >
> >That was a yes/no question: can this condition trigger on correctly
> >working kernels?
>
> How about add unlikely() here?
Please answer my question: can this condition trigger on correctly
working kernels? I think so, but maybe I'm wrong?
Yes/no.
Thanks,
Ingo
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