On 11 September 2014 15:43, Shilpasri G Bhat <[email protected]> wrote: > This patch ensures the cpus to kexec/reboot at nominal frequency. > Nominal frequency is the highest cpu frequency on PowerPC at > which the cores can run without getting throttled. > > If the host kernel had set the cpus to a low pstate and then it > kexecs/reboots to a cpufreq disabled kernel it would cause the target > kernel to perform poorly. It will also increase the boot up time of > the target kernel. So set the cpus to high pstate, in this case to > nominal frequency before rebooting to avoid such scenarios. > > The reboot notifier will set the cpus to nominal frequncy. > > Signed-off-by: Shilpasri G Bhat <[email protected]> > Suggested-by: Viresh Kumar <[email protected]> > Reviewed-by: Preeti U Murthy <[email protected]> > --- > Changes v2->v3: > We return EBUSY when cpufreq governor tries to change the frequency > after rebooting is set to true. This results in console being flushed > with error messages indicating failed attempts to change the > frequency. So instead of returning EBUSY we return 0 to stop the > governor from changing the frequency without alerting a failure to > do the same on reboot, as this is not an errorneaos condition.
Acked-by: Viresh Kumar <[email protected]> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
