Re: [Xen-devel] [PATCH v3 07/11] x86/intel_pstate: changes in cpufreq_del_cpu for CPU offline

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 11.06.15 at 10:28, <wei.w.wang@xxxxxxxxx> wrote:
> cpufreq_cpu_policy is used in intel_pstate_set_pstate(), so we change
> to NULL it after the call of cpufreq_driver->exit. Otherwise, a
> calltrace will show up on your screen due to the reference of a NULL
> pointer when you power down the system.

Apart from what was already said on this patch, I think it is placed
too late in this series (should precede patch 6) or, even better, not
needed at all: ->exit() gets passed the policy being cleaned up, so
I don't follow why the driver needs to consult the per-CPU field to
obtain it.

Plus, if the patch is to be kept, the description suggesting this to be
a problem at system shutdown only is wrong - it can equally well
happen while offlining a CPU. Just saying that the pointer is still
needed would be sufficient.

Jan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel