Re: Oops after cd /sys/.../cpufreq/; rmmod; cat stats/time_in_state

Greg KH
2007-03-22T03:24:11Z

On Tue, Mar 20, 2007 at 01:06:34PM +0300, Alexey Dobriyan wrote:
> On Mon, Mar 19, 2007 at 01:41:25PM -0700, Greg KH wrote:
> > On Mon, Mar 19, 2007 at 06:30:13PM +0300, Alexey Dobriyan wrote:
> > > Steps to reproduce:
> > >
> > > # modprobe p4-clockmod
> > > $ cd /sys/devices/system/cpu/cpu0/cpufreq/
> > > # rmmod p4-clockmod
> > > $ cat stats/time_in_state
> > > Segmentation fault
> >
> > Has this always happened? Or is it new?
>
> I've checked 2.6.17 and up and it happens too.
>
> Some .config peculiarities:
>
> CONFIG_CPU_FREQ=y
> CONFIG_CPU_FREQ_STAT=y
> CONFIG_X86_P4_CLOCKMOD=m
>
> After modprobe/rmmod cpufreq/stats directory appears but doesn't get
> removed. Should it?

Yes.

Well, one can argue that those stats should never be in sysfs at all
anyway, I mean come on, a histogram in sysfs? That's, not ok.

thanks,

greg k-h