RE: [PATCH] cpuidle: use high confidence factors only when considering polling

["Doug Smythies" <dsmythies@telus.net>]

On 2016.03.18 06:12 Rafael J. Wysocki wrote:
> On Fri, Mar 18, 2016 at 7:32 AM, Doug Smythies <dsmythies@telus.net> wrote:
>
>> For my part of it, this patch seems to be not O.K.
>> (reference rvr5 = this patch)
>>
>> Aggregate idle for the 2000 second test. All in minutes.
>> (old tests re-stated)
>>
>> State	k45rc7-rjw10	k45rc7-rjw10-reverted	k45rc7-rjw10-rvr5
>> 0.00	18.07			0.92				18.67
>> 1.00	12.35			19.51				12.82
>> 2.00	3.96			4.28				3.97
>> 3.00	1.55			1.53				1.58
>> 4.00	138.96		141.99			143.80
>>
>> total	174.90		168.24			180.84
>>
>> Energy:
>>>> Kernel 4.5-rc7-rjw10: 61983 Joules
>>>> Kernel 4.5-rc7-rjw10-reverted: 48409 Joules (test 2 was 55040 Joules)
>> Kernel 4.5-rc7-rjw10-rvr5: 62243 Joules
>>
>> I did acquire trace data with this test, but haven't post processed it yet.
>
> I'm wondering what happens if you replace the expected_interval in the
> "expected_interval >
> drv->states[CPUIDLE_DRIVER_STATE_START].target_residency" test with
> data->next_timer_us (with the Rik's patch applied, of course).  Can
> you please try doing that?

O.K. my reference: rvr6 is the above modification to rvr5
It works as well as "reverted"/

State	k45rc7-rjw10-rvr6 (mins)
0.00	0.87
1.00	24.20
2.00	4.05
3.00	1.72
4.00	147.50

total	178.34

Energy:
Kernel 4.5-rc7-rjw10-rvr6: 55864 Joules

Trace data (very crude summary):
Kernel 4.5-rc7-rjw10-rvr5: ~3049 long durations at high CPU load (idle state 0)
Kernel 4.5-rc7-rjw10-rvr5: ~183 long durations at high, but less, CPU load (not all idle state 0)

... Doug