Not write zeroes to APERF and MPERF by ondemand governor. With this other
users can share these MSRs during reads.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@xxxxxxxxx>
---
arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
Index: linux-2.6/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c 2009-02-04 16:05:42.000000000 -0800
+++ linux-2.6/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c 2009-02-04 16:08:51.000000000 -0800
@@ -66,6 +66,7 @@ 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);
@@ -256,9 +257,6 @@ static void read_measured_perf_ctrs(void
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);
}
/*
@@ -277,13 +275,20 @@ static void read_measured_perf_ctrs(void
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 (smp_call_function_single(cpu, read_measured_perf_ctrs, &cur, 1))
+ if (smp_call_function_single(cpu, read_measured_perf_ctrs, &readin, 1))
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
--
--
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