On Thursday, September 11, 2014 05:03:22 PM Viresh Kumar wrote: > On 11 September 2014 15:43, Shilpasri G Bhat > <shilpa.b...@linux.vnet.ibm.com> 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 <shilpa.b...@linux.vnet.ibm.com> > > Suggested-by: Viresh Kumar <viresh.ku...@linaro.org> > > Reviewed-by: Preeti U Murthy <pre...@linux.vnet.ibm.com> > > --- > > 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 <viresh.ku...@linaro.org>
Queued up for 3.18, thanks! -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
