Re: [PATCH RESEND v2 0/3] condition EAS enablement on FI support

Ionela Voinescu
2020-11-18T11:42:56Z

Hi guys,

On Tuesday 27 Oct 2020 at 18:07:10 (+0000), Ionela Voinescu wrote:
> Given the maturity gained by cpufreq-based Frequency Invariance (FI)
> support following the patches at [1], this series conditions Energy
> Aware Scheduling (EAS) enablement on a frequency invariant system.
>
> Currently, EAS can be enabled on a system without FI support, leading
> to incorrect (energy-wise) task placements. As no warning is emitted,
> it could take some debugging effort to track the behavior back to the
> lack of FI support; this series changes that by disabling EAS
> (and advertising it) when FI support is missing.
>
> The series is structured as follows:
> - 1/3 - create function that can rebuild the scheduling and EAS'
> performance domains if EAS' initial conditions change
> - 2/3 - arm64: rebuild scheduling and performance domains in the
> case of late, counter-driven FI initialisation.
> - 3/3 - condition EAS enablement on FI support
>
> RESEND v2: rebase and retest on v5.10-rc1
>

This still applies nicely on v5.10-rc4.

Peter, given that 1/3 and 2/3 are acked, do you think there's anything
else that needs to be done for this?

Thank you,
Ionela.

> v1 -> v2:
> - v1 can be found at [2]
> - 1/2 - moved now "static inline" rebuild_sched_domains_energy() stub
> in sched/topology.h header, as suggested by Quentin.
> - Changed the order of 2/3 and 3/3 to maintain bisection as suggested
> by Quentin.
> - 3/3 - place the warning under sched_debug() as per Quentin and
> Dietmar's recommendations.
>
> [1] Most recent version at:
> https://lore.kernel.org/lkml/20200901205549.30096-1-ionela.voinescu@arm.com/
> [2] https://lore.kernel.org/lkml/20200924123937.20938-1-ionela.voinescu@arm.com/
>
> Many thanks,
> Ionela.
>
> Ionela Voinescu (3):
> sched/topology,schedutil: wrap sched domains rebuild
> arm64: rebuild sched domains on invariance status changes
> sched/topology: condition EAS enablement on FIE support
>
> arch/arm64/kernel/topology.c | 10 ++++++++++
> include/linux/sched/topology.h | 8 ++++++++
> kernel/sched/cpufreq_schedutil.c | 9 +--------
> kernel/sched/topology.c | 27 ++++++++++++++++++++-------
> 4 files changed, 39 insertions(+), 15 deletions(-)
>
>
> base-commit: 3650b228f83adda7e5ee532e2b90429c03f7b9ec
> --
> 2.17.1
>