[PATCH 0/6] arm, arm64: frequency- and cpu-invariant accounting support for task scheduler
From: Juri Lelli <hidden>
Date: 2017-06-12 13:04:22
Also in:
linux-pm, lkml
This time hopefully fixing Vincent's email address.. On 12/06/17 14:00, Juri Lelli wrote:
Hi Dietmar, On 08/06/17 08:55, Dietmar Eggemann wrote:quoted
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