evie/android_kernel_oneplus_msm8998
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core_ctl: redo offline_delay_ms tunable implementation

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The offline_delay_ms tunable is supposed to give hysteresis
effect by delaying the CPU isolation. The current implementation
is not enforcing this correctly due to which we see a CPU is
getting isolated immediately in the next evaluation cycle.

Allow isolating a CPU only if offline_delay_ms is passed
after since the last time we isolated/unisolated/evaluated
without changing the need CPUs.

Change-Id: I9681a11dea1ffa07b2fda6cc9a40af9b453bf553
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
This commit is contained in:
Pavankumar Kondeti 2017-02-10 09:58:58 +05:30
parent dd6494d94e
commit a4fbda7844
1 changed files with 11 additions and 8 deletions
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19
kernel/sched/core_ctl.c
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@ -1,4 +1,4 @@
/* Copyright (c) 2014-2016, The Linux Foundation. All rights reserved.
/* Copyright (c) 2014-2017, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
@ -36,7 +36,7 @@ struct cluster_data {
cpumask_t cpu_mask;
unsigned int need_cpus;
unsigned int task_thres;
s64 last_isolate_ts;
s64 need_ts;
struct list_head lru;
bool pending;
spinlock_t pending_lock;
@ -549,6 +549,7 @@ static bool eval_need(struct cluster_data *cluster)
bool need_flag = false;
unsigned int active_cpus;
unsigned int new_need;
s64 now;
if (unlikely(!cluster->inited))
return 0;
@ -573,9 +574,10 @@ static bool eval_need(struct cluster_data *cluster)
need_flag = adjustment_possible(cluster, new_need);
last_need = cluster->need_cpus;
cluster->need_cpus = new_need;
now = ktime_to_ms(ktime_get());
if (!need_flag) {
if (new_need == last_need) {
cluster->need_ts = now;
spin_unlock_irqrestore(&state_lock, flags);
return 0;
}
@ -583,12 +585,15 @@ static bool eval_need(struct cluster_data *cluster)
if (need_cpus > cluster->active_cpus) {
ret = 1;
} else if (need_cpus < cluster->active_cpus) {
s64 now = ktime_to_ms(ktime_get());
s64 elapsed = now - cluster->last_isolate_ts;
s64 elapsed = now - cluster->need_ts;
ret = elapsed >= cluster->offline_delay_ms;
}
if (ret) {
cluster->need_ts = now;
cluster->need_cpus = new_need;
}
trace_core_ctl_eval_need(cluster->first_cpu, last_need, need_cpus,
ret && need_flag);
spin_unlock_irqrestore(&state_lock, flags);
@ -746,7 +751,6 @@ static void try_to_isolate(struct cluster_data *cluster, unsigned int need)
if (!sched_isolate_cpu(c->cpu)) {
c->isolated_by_us = true;
move_cpu_lru(c);
cluster->last_isolate_ts = ktime_to_ms(ktime_get());
} else {
pr_debug("Unable to isolate CPU%u\n", c->cpu);
}
@ -779,7 +783,6 @@ static void try_to_isolate(struct cluster_data *cluster, unsigned int need)
if (!sched_isolate_cpu(c->cpu)) {
c->isolated_by_us = true;
move_cpu_lru(c);
cluster->last_isolate_ts = ktime_to_ms(ktime_get());
} else {
pr_debug("Unable to isolate CPU%u\n", c->cpu);
}