Messages in this thread | | | Date | Fri, 30 Jun 2017 09:04:25 +0530 | From | Viresh Kumar <> | Subject | Re: [PATCH 3/6] cpufreq: governor: Drop min_sampling_rate |
| |
On 29-06-17, 20:01, Dominik Brodowski wrote: > On Thu, Jun 29, 2017 at 04:29:06PM +0530, Viresh Kumar wrote: > > The cpufreq core and governors aren't supposed to set a limit on how > > fast we want to try changing the frequency. This is currently done for > > the legacy governors with help of min_sampling_rate. > > > > At worst, we may end up setting the sampling rate to a value lower than > > the rate at which frequency can be changed and then one of the CPUs in > > the policy will be only changing frequency for ever. > > Is it safe to issue requests to change the CPU frequency so frequently,
Well, I assumed so. I am not sure the hardware would break though. Overheating ?
> even > on historic hardware such as speedstep-{ich,smi,centrino}? In the past, > these checks more or less disallowed the running of dynamic frequency > scaling at least on speedstep-smi[*],
We must by doing dynamic freq scaling even without this patch. I don't see why you say the above then.
All we do here is that we get rid of the limit on how soon we can change the freq again.
> but maybe on a few other platforms as > well. That's why I am curious on whether this may break systems potentially > on a hardware level if the hardware was not designed to do dynamic frequency > scaling (and not just frequency switches on battery/AC).
Honestly I am not sure if any hardware can break or not, just because of this commit.
-- viresh
| |