On Mon, Jun 30, 2014 at 06:05:35PM +0200, Vincent Guittot wrote:
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);elsereturn 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?