On Fri, 26 Jun 2015, Preeti U Murthy wrote:
> On 06/26/2015 01:17 PM, Thomas Gleixner wrote:
> > if (state == TICK_BROADCAST_ENTER) {
> > + /*
> > + * If the current CPU owns the hrtimer broadcast
> > + * mechanism, it cannot go deep idle and we do not add
> > + * the CPU to the broadcast mask. We don't have to go
> > + * through the EXIT path as the local timer is not
> > + * shutdown.
> > + */
> > + ret = broadcast_needs_cpu(bc, cpu);
> > +
> > + /*
> > + * If the hrtimer broadcast check tells us that the
> > + * cpu cannot go deep idle, or if the broadcast device
> > + * is in periodic mode, we just return.
> > + */
> > + if (ret || tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
> > + goto out;
>
> The check on PERIODIC mode is good, but I don't see the point of moving
> broadcast_needs_cpu() up above. broadcast_shutdown_local() calls
> broadcast_needs_cpu() internally.
>
> Besides, by jumping to 'out', we will miss programming the broadcast
> hrtimer in tick_broadcast_set_event() below, if the cpu happen to be the
> broadcast cpu(which is why it was not allowed to go to deep idle).
Hmm. Need to think a bit more about this convoluted maze ...
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
