linux-stable/drivers/cpuidle
Daniel Lezcano a7fe5190c0 cpuidle: menu: Remove get_loadavg() from the performance multiplier
The function get_loadavg() returns almost always zero. To be more
precise, statistically speaking for a total of 1023379 times passing
in the function, the load is equal to zero 1020728 times, greater than
100, 610 times, the remaining is between 0 and 5.

In 2011, the get_loadavg() was removed from the Android tree because
of the above [1]. At this time, the load was:

unsigned long this_cpu_load(void)
{
        struct rq *this = this_rq();
        return this->cpu_load[0];
}

In 2014, the code was changed by commit 372ba8cb46 (cpuidle: menu: Lookup CPU
runqueues less) and the load is:

void get_iowait_load(unsigned long *nr_waiters, unsigned long *load)
{
        struct rq *rq = this_rq();
        *nr_waiters = atomic_read(&rq->nr_iowait);
        *load = rq->load.weight;
}

with the same result.

Both measurements show using the load in this code path does no matter
anymore. Removing it.

[1] 4dedd9f124

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-10-25 16:49:27 +02:00
..
governors cpuidle: menu: Remove get_loadavg() from the performance multiplier 2018-10-25 16:49:27 +02:00
coupled.c smp: Avoid using two cache lines for struct call_single_data 2017-08-29 15:14:38 +02:00
cpuidle-arm.c ARM: cpuidle: silence error on driver registration failure 2018-06-25 09:33:34 +02:00
cpuidle-at91.c drivers/cpuidle: Convert non-modular drivers to use builtin_platform_driver 2015-06-16 14:12:38 -04:00
cpuidle-big_little.c ARM: MCPM: remove residency argument from mcpm_cpu_suspend() 2015-05-06 11:47:10 -04:00
cpuidle-calxeda.c ARM: migrate to common PSCI client code 2015-08-03 15:38:39 +01:00
cpuidle-clps711x.c drivers/cpuidle: make cpuidle-clps711x.c explicitly non-modular 2015-12-15 00:22:21 +01:00
cpuidle-cps.c Update MIPS email addresses 2017-11-03 09:02:30 -07:00
cpuidle-exynos.c cpuidle: Enable coupled cpuidle support on Exynos3250 platform 2018-03-29 13:06:08 +02:00
cpuidle-kirkwood.c ARM: cpuidle: Remove duplicate header inclusion 2015-03-23 18:03:11 +01:00
cpuidle-mvebu-v7.c cpuidle: mvebu: disable the bind/unbind attributes and use builtin_platform_driver 2015-10-23 12:40:48 +02:00
cpuidle-powernv.c powernv/cpuidle: Use parsed device tree values for cpuidle_init 2018-07-31 19:56:44 +10:00
cpuidle-pseries.c powerpc/pseries/cpuidle: add polling idle for shared processor guests 2018-01-18 15:43:44 +11:00
cpuidle-ux500.c drivers/cpuidle: make cpuidle-ux500.c explicitly non-modular 2015-12-15 00:22:22 +01:00
cpuidle-zynq.c drivers/cpuidle: Convert non-modular drivers to use builtin_platform_driver 2015-06-16 14:12:38 -04:00
cpuidle.c cpuidle: enter_state: Don't needlessly calculate diff time 2018-09-18 09:32:56 +02:00
cpuidle.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
driver.c cpuidle: Make drivers initialize polling state 2017-08-30 03:06:33 +02:00
dt_idle_states.c Merge branch 'pm-sleep' 2017-09-04 00:06:02 +02:00
dt_idle_states.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
governor.c cpuidle: governors: Consolidate PM QoS handling 2018-05-30 23:13:00 +02:00
Kconfig cpuidle: Don't enable all governors by default 2016-01-15 22:39:58 +01:00
Kconfig.arm ARM: cpuidle: Support asymmetric idle definition 2017-06-24 01:51:00 +02:00
Kconfig.mips cpuidle: cpuidle-cps: Enable use with MIPSr6 CPUs. 2016-10-04 16:13:57 +02:00
Kconfig.powerpc powerpc/powernv/cpuidle: Back-end cpuidle driver for powernv platform. 2014-01-29 17:02:24 +11:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
poll_state.c cpuidle: poll_state: Revise loop termination condition 2018-10-04 19:27:27 +02:00
sysfs.c PM: cpuidle/suspend: Add s2idle usage and time state attributes 2018-03-29 13:06:08 +02:00