Re: [REGRESSION] [Linux 3.2] top/htop and all other CPU usage

From: Rafael J. Wysocki
Date: Tue Nov 29 2011 - 17:48:28 EST


On Tuesday, November 29, 2011, Michal Hocko wrote:
> On Tue 29-11-11 12:54:16, Artem S. Tashkinov wrote:
> > > On Nov 29, 2011, Michal Hocko wrote:
> > >
> > > On Tue 29-11-11 13:31:56, Michal Hocko wrote:
> > > > On Tue 29-11-11 11:38:47, Artem S. Tashkinov wrote:
> > > [...]
> > > > > $ grep . -r /sys/devices/system/cpu/cpuidle/
> > > > > /sys/devices/system/cpu/cpuidle/current_driver:intel_idle
> > > > > /sys/devices/system/cpu/cpuidle/current_governor_ro:menu
> > >
> > > Could you try with acpi_idle driver?
> > > echo acpi_idle > /sys/devices/system/cpu/cpuidle/current_driver
> >
> > [root@localhost ~]# echo acpi_idle > /sys/devices/system/cpu/cpuidle/current_driver
> > -bash: /sys/devices/system/cpu/cpuidle/current_driver: Permission denied
>
> It seems that this is cannot be set in runtime:
> SYSDEV_CLASS_ATTR(current_driver, 0444, show_current_driver, NULL);
>
> Or maybe you need to boot with cpuidle_sysfs_switch. According to the
> documentation you might be able to change the governor. I have no idea
> whether this can help somehow but let's try that.
>
> I haven't found any intel_idle machine in my lab so far and all other
> acpi_idle machines seem to work (or at least randomly selected ones) so
> this smells like a major difference in the setup.

I'm able to reproduce that with acpi_driver on one box, but not on demand.

Thanks,
Rafael
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