sched: Allow all architectures to set 'capacity_orig' (26bc3c50) · Commits · 戴 / test

'capacity_orig' is only changed for systems with an SMT sched_domain level in order to reflect the lower capacity of CPUs. Heterogenous systems also have to reflect an original capacity that is different from the default value. Create a more generic function arch_scale_cpu_capacity that can be also used by non SMT platforms to set capacity_orig. The __weak implementation of arch_scale_cpu_capacity() is the previous SMT variant, in order to keep backward compatibility with the use of capacity_orig. arch_scale_smt_capacity() and default_scale_smt_capacity() have been removed as they were not used elsewhere than in arch_scale_cpu_capacity(). Signed-off-by:

Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by:

Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Reviewed-by:

Preeti U. Murthy <preeti@linux.vnet.ibm.com> [ Added default_scale_cpu_capacity() back. ] Signed-off-by:

Peter Zijlstra (Intel) <peterz@infradead.org> Cc: riel@redhat.com Cc: Morten.Rasmussen@arm.com Cc: efault@gmx.de Cc: nicolas.pitre@linaro.org Cc: daniel.lezcano@linaro.org Cc: dietmar.eggemann@arm.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1409051215-16788-5-git-send-email-vincent.guittot@linaro.org Signed-off-by:

Ingo Molnar <mingo@kernel.org>

kernel/sched/fair.c

+11 −16

Original line number	Diff line number	Diff line
		@@ -5705,19 +5705,17 @@ unsigned long __weak arch_scale_freq_capacity(struct sched_domain *sd, int cpu)
		return default_scale_capacity(sd, cpu);
		}

		static unsigned long default_scale_smt_capacity(struct sched_domain *sd, int cpu)
		static unsigned long default_scale_cpu_capacity(struct sched_domain *sd, int cpu)
		{
		unsigned long weight = sd->span_weight;
		unsigned long smt_gain = sd->smt_gain;
		if ((sd->flags & SD_SHARE_CPUCAPACITY) && (sd->span_weight > 1))
		return sd->smt_gain / sd->span_weight;

		smt_gain /= weight;

		return smt_gain;
		return SCHED_CAPACITY_SCALE;
		}

		unsigned long __weak arch_scale_smt_capacity(struct sched_domain *sd, int cpu)
		unsigned long __weak arch_scale_cpu_capacity(struct sched_domain *sd, int cpu)
		{
		return default_scale_smt_capacity(sd, cpu);
		return default_scale_cpu_capacity(sd, cpu);
		}

		static unsigned long scale_rt_capacity(int cpu)
		@@ -5756,18 +5754,15 @@ static unsigned long scale_rt_capacity(int cpu)

		static void update_cpu_capacity(struct sched_domain *sd, int cpu)
		{
		unsigned long weight = sd->span_weight;
		unsigned long capacity = SCHED_CAPACITY_SCALE;
		struct sched_group *sdg = sd->groups;

		if ((sd->flags & SD_SHARE_CPUCAPACITY) && weight > 1) {
		if (sched_feat(ARCH_CAPACITY))
		capacity *= arch_scale_smt_capacity(sd, cpu);
		capacity *= arch_scale_cpu_capacity(sd, cpu);
		else
		capacity *= default_scale_smt_capacity(sd, cpu);
		capacity *= default_scale_cpu_capacity(sd, cpu);

		capacity >>= SCHED_CAPACITY_SHIFT;
		}

		sdg->sgc->capacity_orig = capacity;

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