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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2009-09-03 13:20:03 +0200
committerIngo Molnar <mingo@elte.hu>2009-09-15 16:51:28 +0200
commit8e6598af3f35629c37249a610cf13e73f70db279 (patch)
treea341d416329f5331e4f7c6834d637266ba389b78
parent47fe38fcff0517e67d395c039d2e26d2de688a60 (diff)
downloadlinux-8e6598af3f35629c37249a610cf13e73f70db279.tar.bz2
sched: Feature to disable APERF/MPERF cpu_power
I suspect a feed-back loop between cpuidle and the aperf/mperf cpu_power bits, where when we have idle C-states lower the ratio, which leads to lower cpu_power and then less load, which generates more idle time, etc.. Put in a knob to disable it. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--kernel/sched.c12
-rw-r--r--kernel/sched_features.h5
2 files changed, 15 insertions, 2 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index c210321adcb9..e8e603bf8761 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -3602,11 +3602,19 @@ static void update_cpu_power(struct sched_domain *sd, int cpu)
unsigned long power = SCHED_LOAD_SCALE;
struct sched_group *sdg = sd->groups;
- power *= arch_scale_freq_power(sd, cpu);
+ if (sched_feat(ARCH_POWER))
+ power *= arch_scale_freq_power(sd, cpu);
+ else
+ power *= default_scale_freq_power(sd, cpu);
+
power >>= SCHED_LOAD_SHIFT;
if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) {
- power *= arch_scale_smt_power(sd, cpu);
+ if (sched_feat(ARCH_POWER))
+ power *= arch_scale_smt_power(sd, cpu);
+ else
+ power *= default_scale_smt_power(sd, cpu);
+
power >>= SCHED_LOAD_SHIFT;
}
diff --git a/kernel/sched_features.h b/kernel/sched_features.h
index e98c2e8de1d5..294e10edd3c8 100644
--- a/kernel/sched_features.h
+++ b/kernel/sched_features.h
@@ -82,6 +82,11 @@ SCHED_FEAT(LAST_BUDDY, 1)
*/
SCHED_FEAT(CACHE_HOT_BUDDY, 1)
+/*
+ * Use arch dependent cpu power functions
+ */
+SCHED_FEAT(ARCH_POWER, 0)
+
SCHED_FEAT(HRTICK, 0)
SCHED_FEAT(DOUBLE_TICK, 0)
SCHED_FEAT(LB_BIAS, 1)