diff options
| -rw-r--r-- | arch/x86/kernel/cpu/Makefile | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/aperfmperf.c | 74 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/cpu.h | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/proc.c | 6 | ||||
| -rw-r--r-- | fs/proc/cpuinfo.c | 6 | ||||
| -rw-r--r-- | include/linux/cpufreq.h | 1 |
6 files changed, 68 insertions, 24 deletions
diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile index 90cb82dbba57..570e8bb1f386 100644 --- a/arch/x86/kernel/cpu/Makefile +++ b/arch/x86/kernel/cpu/Makefile @@ -22,7 +22,7 @@ obj-y += common.o obj-y += rdrand.o obj-y += match.o obj-y += bugs.o -obj-$(CONFIG_CPU_FREQ) += aperfmperf.o +obj-y += aperfmperf.o obj-y += cpuid-deps.o obj-$(CONFIG_PROC_FS) += proc.o diff --git a/arch/x86/kernel/cpu/aperfmperf.c b/arch/x86/kernel/cpu/aperfmperf.c index 957813e0180d..7eba34df54c3 100644 --- a/arch/x86/kernel/cpu/aperfmperf.c +++ b/arch/x86/kernel/cpu/aperfmperf.c @@ -14,6 +14,8 @@ #include <linux/percpu.h> #include <linux/smp.h> +#include "cpu.h" + struct aperfmperf_sample { unsigned int khz; ktime_t time; @@ -24,7 +26,7 @@ struct aperfmperf_sample { static DEFINE_PER_CPU(struct aperfmperf_sample, samples); #define APERFMPERF_CACHE_THRESHOLD_MS 10 -#define APERFMPERF_REFRESH_DELAY_MS 20 +#define APERFMPERF_REFRESH_DELAY_MS 10 #define APERFMPERF_STALE_THRESHOLD_MS 1000 /* @@ -38,8 +40,6 @@ static void aperfmperf_snapshot_khz(void *dummy) u64 aperf, aperf_delta; u64 mperf, mperf_delta; struct aperfmperf_sample *s = this_cpu_ptr(&samples); - ktime_t now = ktime_get(); - s64 time_delta = ktime_ms_delta(now, s->time); unsigned long flags; local_irq_save(flags); @@ -57,38 +57,68 @@ static void aperfmperf_snapshot_khz(void *dummy) if (mperf_delta == 0) return; - s->time = now; + s->time = ktime_get(); s->aperf = aperf; s->mperf = mperf; - - /* If the previous iteration was too long ago, discard it. */ - if (time_delta > APERFMPERF_STALE_THRESHOLD_MS) - s->khz = 0; - else - s->khz = div64_u64((cpu_khz * aperf_delta), mperf_delta); + s->khz = div64_u64((cpu_khz * aperf_delta), mperf_delta); } -unsigned int arch_freq_get_on_cpu(int cpu) +static bool aperfmperf_snapshot_cpu(int cpu, ktime_t now, bool wait) { - s64 time_delta; - unsigned int khz; + s64 time_delta = ktime_ms_delta(now, per_cpu(samples.time, cpu)); + + /* Don't bother re-computing within the cache threshold time. */ + if (time_delta < APERFMPERF_CACHE_THRESHOLD_MS) + return true; + + smp_call_function_single(cpu, aperfmperf_snapshot_khz, NULL, wait); + + /* Return false if the previous iteration was too long ago. */ + return time_delta <= APERFMPERF_STALE_THRESHOLD_MS; +} +unsigned int aperfmperf_get_khz(int cpu) +{ if (!cpu_khz) return 0; if (!static_cpu_has(X86_FEATURE_APERFMPERF)) return 0; - /* Don't bother re-computing within the cache threshold time. */ - time_delta = ktime_ms_delta(ktime_get(), per_cpu(samples.time, cpu)); - khz = per_cpu(samples.khz, cpu); - if (khz && time_delta < APERFMPERF_CACHE_THRESHOLD_MS) - return khz; + aperfmperf_snapshot_cpu(cpu, ktime_get(), true); + return per_cpu(samples.khz, cpu); +} - smp_call_function_single(cpu, aperfmperf_snapshot_khz, NULL, 1); - khz = per_cpu(samples.khz, cpu); - if (khz) - return khz; +void arch_freq_prepare_all(void) +{ + ktime_t now = ktime_get(); + bool wait = false; + int cpu; + + if (!cpu_khz) + return; + + if (!static_cpu_has(X86_FEATURE_APERFMPERF)) + return; + + for_each_online_cpu(cpu) + if (!aperfmperf_snapshot_cpu(cpu, now, false)) + wait = true; + + if (wait) + msleep(APERFMPERF_REFRESH_DELAY_MS); +} + +unsigned int arch_freq_get_on_cpu(int cpu) +{ + if (!cpu_khz) + return 0; + + if (!static_cpu_has(X86_FEATURE_APERFMPERF)) + return 0; + + if (aperfmperf_snapshot_cpu(cpu, ktime_get(), true)) + return per_cpu(samples.khz, cpu); msleep(APERFMPERF_REFRESH_DELAY_MS); smp_call_function_single(cpu, aperfmperf_snapshot_khz, NULL, 1); diff --git a/arch/x86/kernel/cpu/cpu.h b/arch/x86/kernel/cpu/cpu.h index f52a370b6c00..e806b11a99af 100644 --- a/arch/x86/kernel/cpu/cpu.h +++ b/arch/x86/kernel/cpu/cpu.h @@ -47,4 +47,7 @@ extern const struct cpu_dev *const __x86_cpu_dev_start[], extern void get_cpu_cap(struct cpuinfo_x86 *c); extern void cpu_detect_cache_sizes(struct cpuinfo_x86 *c); + +unsigned int aperfmperf_get_khz(int cpu); + #endif /* ARCH_X86_CPU_H */ diff --git a/arch/x86/kernel/cpu/proc.c b/arch/x86/kernel/cpu/proc.c index 6b7e17bf0b71..e7ecedafa1c8 100644 --- a/arch/x86/kernel/cpu/proc.c +++ b/arch/x86/kernel/cpu/proc.c @@ -5,6 +5,8 @@ #include <linux/seq_file.h> #include <linux/cpufreq.h> +#include "cpu.h" + /* * Get CPU information for use by the procfs. */ @@ -78,9 +80,11 @@ static int show_cpuinfo(struct seq_file *m, void *v) seq_printf(m, "microcode\t: 0x%x\n", c->microcode); if (cpu_has(c, X86_FEATURE_TSC)) { - unsigned int freq = cpufreq_quick_get(cpu); + unsigned int freq = aperfmperf_get_khz(cpu); if (!freq) + freq = cpufreq_quick_get(cpu); + if (!freq) freq = cpu_khz; seq_printf(m, "cpu MHz\t\t: %u.%03u\n", freq / 1000, (freq % 1000)); diff --git a/fs/proc/cpuinfo.c b/fs/proc/cpuinfo.c index e0f867cd8553..96f1087e372c 100644 --- a/fs/proc/cpuinfo.c +++ b/fs/proc/cpuinfo.c @@ -1,12 +1,18 @@ // SPDX-License-Identifier: GPL-2.0 +#include <linux/cpufreq.h> #include <linux/fs.h> #include <linux/init.h> #include <linux/proc_fs.h> #include <linux/seq_file.h> +__weak void arch_freq_prepare_all(void) +{ +} + extern const struct seq_operations cpuinfo_op; static int cpuinfo_open(struct inode *inode, struct file *file) { + arch_freq_prepare_all(); return seq_open(file, &cpuinfo_op); } diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 28734ee185a7..065f3a8eb486 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -917,6 +917,7 @@ static inline bool policy_has_boost_freq(struct cpufreq_policy *policy) } #endif +extern void arch_freq_prepare_all(void); extern unsigned int arch_freq_get_on_cpu(int cpu); extern void arch_set_freq_scale(struct cpumask *cpus, unsigned long cur_freq, |