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Re: [Xen-devel] [V5] x86/cpuidle: get accurate C0 value with xenpm tool



>>> On 20.05.15 at 10:36, <huaitong.han@xxxxxxxxx> wrote:
> On Wed, 2015-05-20 at 02:42 +0000, Han, Huaitong wrote:
>> On Tue, 2015-05-19 at 10:01 +0100, Jan Beulich wrote:
>> > >>> On 14.05.15 at 07:23, <huaitong.han@xxxxxxxxx> wrote:
>> > > @@ -1172,7 +1196,10 @@ int pmstat_get_cx_stat(uint32_t cpuid, struct 
>> > > pm_cx_stat *stat)
>> > >  {
>> > >      struct acpi_processor_power *power = processor_powers[cpuid];
>> > >      uint64_t idle_usage = 0, idle_res = 0;
>> > > -    uint64_t usage[ACPI_PROCESSOR_MAX_POWER], 
>> > > res[ACPI_PROCESSOR_MAX_POWER];
>> > > +    uint64_t last_state_update_tick, current_stime, current_tick;
>> > > +    uint64_t usage[ACPI_PROCESSOR_MAX_POWER] = { 0 };
>> > > +    uint64_t res_ticks[ACPI_PROCESSOR_MAX_POWER] = { 0 };
>> > > +    uint64_t res[ACPI_PROCESSOR_MAX_POWER] = { 0 };
>> > 
>> > Not yet another array on the stack please - I can't see why you
>> > can't get away with just res[].
>> res_ticks just is a temp array. I can use a temp variable for
>> ticks_to_ns  transform, like "tmp=res[i];res[i]=ticks_to_ns(tmp);", and
>> the array named res[] is better in terms of origin source code.
> use "res[i]=ticks_to_ns((uint64_t)res[i])" without tmp varialbe.

Exactly.

Jan


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