From: Venkatesh Pallipadi <venkatesh.pallipadi@xxxxxxxxx>
Do not write zeroes to APERF and MPERF by ondemand governor. With this
change, other users can share these MSRs for reads.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@xxxxxxxxx>
Signed-off-by: Len Brown <len.brown@xxxxxxxxx>
---
arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c | 15 ++++++++++-----
1 files changed, 10 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
index 340bdbe..9d3af38 100644
--- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
+++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
@@ -68,6 +68,7 @@ struct acpi_cpufreq_data {
unsigned int max_freq;
unsigned int resume;
unsigned int cpu_feature;
+ u64 saved_aperf, saved_mperf;
};
static DEFINE_PER_CPU(struct acpi_cpufreq_data *, drv_data);
@@ -259,9 +260,6 @@ static long read_measured_perf_ctrs(void *_cur)
rdmsr(MSR_IA32_APERF, cur->aperf.split.lo, cur->aperf.split.hi);
rdmsr(MSR_IA32_MPERF, cur->mperf.split.lo, cur->mperf.split.hi);
- wrmsr(MSR_IA32_APERF, 0, 0);
- wrmsr(MSR_IA32_MPERF, 0, 0);
-
return 0;
}
@@ -281,13 +279,20 @@ static long read_measured_perf_ctrs(void *_cur)
static unsigned int get_measured_perf(struct cpufreq_policy *policy,
unsigned int cpu)
{
- struct perf_pair cur;
+ struct perf_pair readin, cur;
unsigned int perf_percent;
unsigned int retval;
- if (!work_on_cpu(cpu, read_measured_perf_ctrs, &cur))
+ if (!work_on_cpu(cpu, read_measured_perf_ctrs, &readin))
return 0;
+ cur.aperf.whole = readin.aperf.whole -
+ per_cpu(drv_data, cpu)->saved_aperf;
+ cur.mperf.whole = readin.mperf.whole -
+ per_cpu(drv_data, cpu)->saved_mperf;
+ per_cpu(drv_data, cpu)->saved_aperf = readin.aperf.whole;
+ per_cpu(drv_data, cpu)->saved_mperf = readin.mperf.whole;
+
#ifdef __i386__
/*
* We dont want to do 64 bit divide with 32 bit kernel
--
1.6.0.6
--
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