From c8ed99533dbc0fcc1142671ec80acb33045d2999 Mon Sep 17 00:00:00 2001 From: Vincent Donnefort Date: Wed, 8 Sep 2021 15:05:23 +0100 Subject: [PATCH] PM: EM: Mark inefficient states Some SoCs, such as the sd855 have OPPs within the same performance domain, whose cost is higher than others with a higher frequency. Even though those OPPs are interesting from a cooling perspective, it makes no sense to use them when the device can run at full capacity. Those OPPs handicap the performance domain, when choosing the most energy-efficient CPU and are wasting energy. They are inefficient. Hence, add support for such OPPs to the Energy Model. The table can now be read skipping inefficient performance states (and by extension, inefficient OPPs). Signed-off-by: Vincent Donnefort Reviewed-by: Matthias Kaehlcke Reviewed-by: Lukasz Luba Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki --- include/linux/energy_model.h | 12 ++++++++++++ kernel/power/energy_model.c | 4 +++- 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h index 39dcadd492b53..3641ca4acf042 100644 --- a/include/linux/energy_model.h +++ b/include/linux/energy_model.h @@ -17,13 +17,25 @@ * device). It can be a total power: static and dynamic. * @cost: The cost coefficient associated with this level, used during * energy calculation. Equal to: power * max_frequency / frequency + * @flags: see "em_perf_state flags" description below. */ struct em_perf_state { unsigned long frequency; unsigned long power; unsigned long cost; + unsigned long flags; }; +/* + * em_perf_state flags: + * + * EM_PERF_STATE_INEFFICIENT: The performance state is inefficient. There is + * in this em_perf_domain, another performance state with a higher frequency + * but a lower or equal power cost. Such inefficient states are ignored when + * using em_pd_get_efficient_*() functions. + */ +#define EM_PERF_STATE_INEFFICIENT BIT(0) + /** * struct em_perf_domain - Performance domain * @table: List of performance states, in ascending order diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c index 97e62469a6b32..6d84383475353 100644 --- a/kernel/power/energy_model.c +++ b/kernel/power/energy_model.c @@ -2,7 +2,7 @@ /* * Energy Model of devices * - * Copyright (c) 2018-2020, Arm ltd. + * Copyright (c) 2018-2021, Arm ltd. * Written by: Quentin Perret, Arm ltd. * Improvements provided by: Lukasz Luba, Arm ltd. */ @@ -42,6 +42,7 @@ static void em_debug_create_ps(struct em_perf_state *ps, struct dentry *pd) debugfs_create_ulong("frequency", 0444, d, &ps->frequency); debugfs_create_ulong("power", 0444, d, &ps->power); debugfs_create_ulong("cost", 0444, d, &ps->cost); + debugfs_create_ulong("inefficient", 0444, d, &ps->flags); } static int em_debug_cpus_show(struct seq_file *s, void *unused) @@ -162,6 +163,7 @@ static int em_create_perf_table(struct device *dev, struct em_perf_domain *pd, table[i].cost = div64_u64(fmax * power_res, table[i].frequency); if (table[i].cost >= prev_cost) { + table[i].flags = EM_PERF_STATE_INEFFICIENT; dev_dbg(dev, "EM: OPP:%lu is inefficient\n", table[i].frequency); } else { -- 2.30.2