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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2009-09-03 13:20:03 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-09-15 16:51:28 +0200 |
| commit | 8e6598af3f35629c37249a610cf13e73f70db279 (patch) | |
| tree | a341d416329f5331e4f7c6834d637266ba389b78 /kernel/sched.c | |
| parent | 47fe38fcff0517e67d395c039d2e26d2de688a60 (diff) | |
| download | lwn-8e6598af3f35629c37249a610cf13e73f70db279.tar.gz lwn-8e6598af3f35629c37249a610cf13e73f70db279.zip | |
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>
Diffstat (limited to 'kernel/sched.c')
| -rw-r--r-- | kernel/sched.c | 12 |
1 files changed, 10 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; } |