Hi Dietmar,

On 08/06/17 08:55, Dietmar Eggemann wrote:

For a more accurate (i.e. frequency- and cpu-invariant) load-tracking
the task scheduler needs a frequency-scaling and on a heterogeneous
system a cpu-scaling correction factor.

This patch-set implements a Frequency Invariance Engine (FIE)
(topology_get_freq_scale()) in drivers/base/arch_topology.c to provide
a frequency-scaling correction factor.

The Cpu Invariance Engine (CIE) (topology_get_cpu_scale()) providing a
cpu-scaling correction factor was already introduced by the "Fix issues
and factorize arm/arm64 capacity information code" patch-set [1].

This patch-set also enables the frequency- and cpu-invariant accounting
support. Enabling here means to associate (wire) the task scheduler
cname arch_scale_freq_capacity and arch_scale_cpu_capacity with the FIE
and CIE function names from drivers/base/arch_topology.c. This replaces
the task scheduler's default FIE and CIE in kernel/sched/sched.h.

Patch high level description:

 [   01/06] Rework cpufreq policy notifier for frequency-invariant
            accounting support
 [   02/06] Frequency Invariance Engine (FIE)
 [03,04/06] Enable frequency- and cpu-invariant accounting support on
            arm
 [05,06/06] Enable frequency- and cpu-invariant accounting support on
            arm64

The patch-set is based on top of linux-next/master (tag: next-20170607)
and it is also available from:

 git://linux-arm.org/linux-de.git upstream/freq_and_cpu_inv

It has been tested on TC2 (arm) and JUNO (arm64) by running a ramp-up
rt-app task pinned to a cpu with the ondemand cpufreq governor and
checking the load-tracking signals of this task.

The whole set looks OK to me, and I tested it as well.

Feel free to add my

Reviewed-and-tested-by: Juri Lelli [off-list ref]

to it.

Best,

- Juri