[patch 05/10] x86/aperfmperf: Put frequency invariance aperf/mperf data into a struct

From: Thomas Gleixner
Date: Fri Apr 15 2022 - 15:20:37 EST


Preparation for sharing code with the CPU frequency portion of the
aperf/mperf code.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
arch/x86/kernel/cpu/aperfmperf.c | 26 +++++++++++++++-----------
1 file changed, 15 insertions(+), 11 deletions(-)

--- a/arch/x86/kernel/cpu/aperfmperf.c
+++ b/arch/x86/kernel/cpu/aperfmperf.c
@@ -22,6 +22,13 @@

#include "cpu.h"

+struct aperfmperf {
+ u64 aperf;
+ u64 mperf;
+};
+
+static DEFINE_PER_CPU_SHARED_ALIGNED(struct aperfmperf, cpu_samples);
+
struct aperfmperf_sample {
unsigned int khz;
atomic_t scfpending;
@@ -194,8 +201,6 @@ unsigned int arch_freq_get_on_cpu(int cp

DEFINE_STATIC_KEY_FALSE(arch_scale_freq_key);

-static DEFINE_PER_CPU(u64, arch_prev_aperf);
-static DEFINE_PER_CPU(u64, arch_prev_mperf);
static u64 arch_turbo_freq_ratio = SCHED_CAPACITY_SCALE;
static u64 arch_max_freq_ratio = SCHED_CAPACITY_SCALE;

@@ -407,8 +412,8 @@ static void init_counter_refs(void)
rdmsrl(MSR_IA32_APERF, aperf);
rdmsrl(MSR_IA32_MPERF, mperf);

- this_cpu_write(arch_prev_aperf, aperf);
- this_cpu_write(arch_prev_mperf, mperf);
+ this_cpu_write(cpu_samples.aperf, aperf);
+ this_cpu_write(cpu_samples.mperf, mperf);
}

#ifdef CONFIG_PM_SLEEP
@@ -474,9 +479,8 @@ DEFINE_PER_CPU(unsigned long, arch_freq_

void arch_scale_freq_tick(void)
{
- u64 freq_scale;
- u64 aperf, mperf;
- u64 acnt, mcnt;
+ struct aperfmperf *s = this_cpu_ptr(&cpu_samples);
+ u64 aperf, mperf, acnt, mcnt, freq_scale;

if (!arch_scale_freq_invariant())
return;
@@ -484,11 +488,11 @@ void arch_scale_freq_tick(void)
rdmsrl(MSR_IA32_APERF, aperf);
rdmsrl(MSR_IA32_MPERF, mperf);

- acnt = aperf - this_cpu_read(arch_prev_aperf);
- mcnt = mperf - this_cpu_read(arch_prev_mperf);
+ acnt = aperf - s->aperf;
+ mcnt = mperf - s->mperf;

- this_cpu_write(arch_prev_aperf, aperf);
- this_cpu_write(arch_prev_mperf, mperf);
+ s->aperf = aperf;
+ s->mperf = mperf;

if (check_shl_overflow(acnt, 2*SCHED_CAPACITY_SHIFT, &acnt))
goto error;