[PATCH v3 04/12] sched: Allow all archs to set the power_orig
From: peterz@infradead.org (Peter Zijlstra)
Date: 2014-07-09 10:57:39
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On Mon, Jun 30, 2014 at 06:05:35PM +0200, Vincent Guittot wrote:
quoted hunk ↗ jump to hunk
power_orig is only changed for system with a SMT sched_domain level in order to reflect the lower capacity of CPUs. Heterogenous system also have to reflect an original capacity that is different from the default value. Create a more generic function arch_scale_cpu_power that can be also used by non SMT platform to set power_orig. The weak behavior of arch_scale_cpu_power is the previous SMT one in order to keep backward compatibility in the use of power_orig. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> --- kernel/sched/fair.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-)diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 148b277..f0bba5f 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c@@ -5614,6 +5614,20 @@ unsigned long __weak arch_scale_smt_capacity(struct sched_domain *sd, int cpu) return default_scale_smt_capacity(sd, cpu); } +unsigned long __weak arch_scale_cpu_capacity(struct sched_domain *sd, int cpu) +{ + unsigned long weight = sd->span_weight; + + if ((sd->flags & SD_SHARE_CPUCAPACITY) && weight > 1) { + if (sched_feat(ARCH_CAPACITY)) + return arch_scale_smt_capacity(sd, cpu); + else + return default_scale_smt_capacity(sd, cpu); + } + + return SCHED_CAPACITY_SCALE; +}
The only caller of arch_scale_smt_capacity is now an arch_ function
itself; which makes it entirely redundant, no?
Also, sched_feat() and default_scale_smt_capability() aren't available
to arch implementations of this function and can thus not retain
semantics.
Seeing how we currently don't have any arch_scale_smt_capacity
implementations other than the default we can easily replace it entirely
with something like:
unsigned long __weak arch_scale_cpu_capacity()
{
if ((sd->flags & SD_SHARE_CPUCAPACITY) && (sd->span_weight > 1))
return sd->smt_gain / sd->span_weight;
return SCHED_CAPACITY_SCALE;
}
Hmm?
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