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sched/fair: Remove wake_cap()

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Capacity-awareness in the wake-up path previously involved disabling
wake_affine in certain scenarios. We have just made select_idle_sibling()
capacity-aware, so this isn't needed anymore.

Remove wake_cap() entirely.

Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com>
[Changelog tweaks]
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
[Changelog tweaks]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200206191957.12325-5-valentin.schneider@arm.com
This commit is contained in:
Morten Rasmussen 2020-02-06 19:19:57 +00:00 committed by Thomas Gleixner
parent f8459197e7
commit 000619680c
1 changed files with 1 additions and 29 deletions
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30
kernel/sched/fair.c
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@ -6145,33 +6145,6 @@ static unsigned long cpu_util_without(int cpu, struct task_struct *p)
return min_t(unsigned long, util, capacity_orig_of(cpu));
}
/*
* Disable WAKE_AFFINE in the case where task @p doesn't fit in the
* capacity of either the waking CPU @cpu or the previous CPU @prev_cpu.
*
* In that case WAKE_AFFINE doesn't make sense and we'll let
* BALANCE_WAKE sort things out.
*/
static int wake_cap(struct task_struct *p, int cpu, int prev_cpu)
{
long min_cap, max_cap;
if (!static_branch_unlikely(&sched_asym_cpucapacity))
return 0;
min_cap = min(capacity_orig_of(prev_cpu), capacity_orig_of(cpu));
max_cap = cpu_rq(cpu)->rd->max_cpu_capacity;
/* Minimum capacity is close to max, no need to abort wake_affine */
if (max_cap - min_cap < max_cap >> 3)
return 0;
/* Bring task utilization in sync with prev_cpu */
sync_entity_load_avg(&p->se);
return !task_fits_capacity(p, min_cap);
}
/*
* Predicts what cpu_util(@cpu) would return if @p was migrated (and enqueued)
* to @dst_cpu.
@ -6436,8 +6409,7 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_f
new_cpu = prev_cpu;
}
want_affine = !wake_wide(p) && !wake_cap(p, cpu, prev_cpu) &&
cpumask_test_cpu(cpu, p->cpus_ptr);
want_affine = !wake_wide(p) && cpumask_test_cpu(cpu, p->cpus_ptr);
}
rcu_read_lock();