From e39ad415ac15116df213dfa2aa2a4f1b0857af9c Mon Sep 17 00:00:00 2001 From: Mike Travis Date: Sun, 4 Jan 2009 05:18:10 -0800 Subject: cpumask: use work_on_cpu in acpi-cpufreq.c for read_measured_perf_ctrs Impact: use new cpumask API to reduce stack usage Replace the saving of current->cpus_allowed and set_cpus_allowed_ptr() with a work_on_cpu function for read_measured_perf_ctrs(). Basically splits off the work function from get_measured_perf which is run on the designated cpu. Moves definition of struct perf_cur out of function local namespace, and is used as the work function argument. References in get_measured_perf use values in the perf_cur struct. Signed-off-by: Mike Travis Acked-by: Rusty Russell Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c | 83 ++++++++++++++++-------------- 1 file changed, 43 insertions(+), 40 deletions(-) (limited to 'arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c') diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c index 4e4f2b04dac2..06fcd8f9323c 100644 --- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c +++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c @@ -245,6 +245,30 @@ static u32 get_cur_val(const struct cpumask *mask) return cmd.val; } +struct perf_cur { + union { + struct { + u32 lo; + u32 hi; + } split; + u64 whole; + } aperf_cur, mperf_cur; +}; + + +static long read_measured_perf_ctrs(void *_cur) +{ + struct perf_cur *cur = _cur; + + rdmsr(MSR_IA32_APERF, cur->aperf_cur.split.lo, cur->aperf_cur.split.hi); + rdmsr(MSR_IA32_MPERF, cur->mperf_cur.split.lo, cur->mperf_cur.split.hi); + + wrmsr(MSR_IA32_APERF, 0, 0); + wrmsr(MSR_IA32_MPERF, 0, 0); + + return 0; +} + /* * Return the measured active (C0) frequency on this CPU since last call * to this function. @@ -261,31 +285,12 @@ static u32 get_cur_val(const struct cpumask *mask) static unsigned int get_measured_perf(struct cpufreq_policy *policy, unsigned int cpu) { - union { - struct { - u32 lo; - u32 hi; - } split; - u64 whole; - } aperf_cur, mperf_cur; - - cpumask_t saved_mask; + struct perf_cur cur; unsigned int perf_percent; unsigned int retval; - saved_mask = current->cpus_allowed; - set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu)); - if (get_cpu() != cpu) { - /* We were not able to run on requested processor */ - put_cpu(); + if (!work_on_cpu(cpu, read_measured_perf_ctrs, &cur)) return 0; - } - - rdmsr(MSR_IA32_APERF, aperf_cur.split.lo, aperf_cur.split.hi); - rdmsr(MSR_IA32_MPERF, mperf_cur.split.lo, mperf_cur.split.hi); - - wrmsr(MSR_IA32_APERF, 0,0); - wrmsr(MSR_IA32_MPERF, 0,0); #ifdef __i386__ /* @@ -293,37 +298,39 @@ static unsigned int get_measured_perf(struct cpufreq_policy *policy, * Get an approximate value. Return failure in case we cannot get * an approximate value. */ - if (unlikely(aperf_cur.split.hi || mperf_cur.split.hi)) { + if (unlikely(cur.aperf_cur.split.hi || cur.mperf_cur.split.hi)) { int shift_count; u32 h; - h = max_t(u32, aperf_cur.split.hi, mperf_cur.split.hi); + h = max_t(u32, cur.aperf_cur.split.hi, cur.mperf_cur.split.hi); shift_count = fls(h); - aperf_cur.whole >>= shift_count; - mperf_cur.whole >>= shift_count; + cur.aperf_cur.whole >>= shift_count; + cur.mperf_cur.whole >>= shift_count; } - if (((unsigned long)(-1) / 100) < aperf_cur.split.lo) { + if (((unsigned long)(-1) / 100) < cur.aperf_cur.split.lo) { int shift_count = 7; - aperf_cur.split.lo >>= shift_count; - mperf_cur.split.lo >>= shift_count; + cur.aperf_cur.split.lo >>= shift_count; + cur.mperf_cur.split.lo >>= shift_count; } - if (aperf_cur.split.lo && mperf_cur.split.lo) - perf_percent = (aperf_cur.split.lo * 100) / mperf_cur.split.lo; + if (cur.aperf_cur.split.lo && cur.mperf_cur.split.lo) + perf_percent = (cur.aperf_cur.split.lo * 100) / + cur.mperf_cur.split.lo; else perf_percent = 0; #else - if (unlikely(((unsigned long)(-1) / 100) < aperf_cur.whole)) { + if (unlikely(((unsigned long)(-1) / 100) < cur.aperf_cur.whole)) { int shift_count = 7; - aperf_cur.whole >>= shift_count; - mperf_cur.whole >>= shift_count; + cur.aperf_cur.whole >>= shift_count; + cur.mperf_cur.whole >>= shift_count; } - if (aperf_cur.whole && mperf_cur.whole) - perf_percent = (aperf_cur.whole * 100) / mperf_cur.whole; + if (cur.aperf_cur.whole && cur.mperf_cur.whole) + perf_percent = (cur.aperf_cur.whole * 100) / + cur.mperf_cur.whole; else perf_percent = 0; @@ -331,10 +338,6 @@ static unsigned int get_measured_perf(struct cpufreq_policy *policy, retval = per_cpu(drv_data, policy->cpu)->max_freq * perf_percent / 100; - put_cpu(); - set_cpus_allowed_ptr(current, &saved_mask); - - dprintk("cpu %d: performance percent %d\n", cpu, perf_percent); return retval; } @@ -352,7 +355,7 @@ static unsigned int get_cur_freq_on_cpu(unsigned int cpu) } cached_freq = data->freq_table[data->acpi_data->state].frequency; - freq = extract_freq(get_cur_val(&cpumask_of_cpu(cpu)), data); + freq = extract_freq(get_cur_val(cpumask_of(cpu)), data); if (freq != cached_freq) { /* * The dreaded BIOS frequency change behind our back. -- cgit v1.2.1