On Thu, Aug 27, 2015 at 04:07:43PM +0800, Huang Rui wrote: > This patch introduces an algorithm that computes the average power by > reading a delta value of “core power accumulator” register during > measurement interval, and then dividing delta value by the length of > the time interval. > > User is able to use power1_acc entry to measure the processor power > consumption and power1_acc just needs to be read twice with an needed > interval in-between. > > A simple example: > > $ cat /sys/bus/pci/devices/0000\:00\:18.4/hwmon/hwmon0/power1_acc > $ sleep 10000s > $ cat /sys/bus/pci/devices/0000\:00\:18.4/hwmon/hwmon0/power1_acc > > The result is current average processor power consumption in 10000 > seconds. The unit of the result is uWatt. > > Signed-off-by: Huang Rui <[email protected]> > --- > drivers/hwmon/fam15h_power.c | 62 > ++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 62 insertions(+) > > diff --git a/drivers/hwmon/fam15h_power.c b/drivers/hwmon/fam15h_power.c > index d529e4b..3bab797 100644 > --- a/drivers/hwmon/fam15h_power.c > +++ b/drivers/hwmon/fam15h_power.c > @@ -60,6 +60,7 @@ struct fam15h_power_data { > u64 cu_acc_power[MAX_CUS]; > /* performance timestamp counter */ > u64 cpu_sw_pwr_ptsc[MAX_CUS]; > + struct mutex acc_pwr_mutex; > }; > > static ssize_t show_power(struct device *dev, > @@ -121,17 +122,74 @@ static DEVICE_ATTR(power1_crit, S_IRUGO, > show_power_crit, NULL); > static struct attribute_group fam15h_power_group; > __ATTRIBUTE_GROUPS(fam15h_power); > > +static ssize_t show_power_acc(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + int cpu, cu, cu_num, cores_per_cu; > + u64 curr_cu_acc_power[MAX_CUS], > + curr_ptsc[MAX_CUS], jdelta[MAX_CUS]; > + u64 tdelta, avg_acc; > + struct fam15h_power_data *data = dev_get_drvdata(dev); > + > + cores_per_cu = amd_get_cores_per_cu(); > + cu_num = boot_cpu_data.x86_max_cores / cores_per_cu; > + > + for (cpu = 0, avg_acc = 0; cpu < cu_num * cores_per_cu; cpu += > cores_per_cu) { > + cu = cpu / cores_per_cu; > + if (rdmsrl_safe_on_cpu(cpu, MSR_F15H_PTSC, &curr_ptsc[cu])) { > + pr_err("Failed to read PTSC counter MSR on core%d\n", > + cpu); > + return 0; > + } > + > + if (rdmsrl_safe_on_cpu(cpu, MSR_F15H_CU_PWR_ACCUMULATOR, > + &curr_cu_acc_power[cu])) { > + pr_err("Failed to read compute unit power accumulator > MSR on core%d\n", > + cpu); > + return 0; > + } > + > + if (curr_cu_acc_power[cu] < data->cu_acc_power[cu]) { > + jdelta[cu] = data->max_cu_acc_power + > curr_cu_acc_power[cu]; > + jdelta[cu] -= data->cu_acc_power[cu]; > + } else { > + jdelta[cu] = curr_cu_acc_power[cu] - > data->cu_acc_power[cu]; > + } > + tdelta = curr_ptsc[cu] - data->cpu_sw_pwr_ptsc[cu]; > + jdelta[cu] *= data->cpu_pwr_sample_ratio * 1000; > + do_div(jdelta[cu], tdelta); > + > + mutex_lock(&data->acc_pwr_mutex); > + data->cu_acc_power[cu] = curr_cu_acc_power[cu]; > + data->cpu_sw_pwr_ptsc[cu] = curr_ptsc[cu]; > + mutex_unlock(&data->acc_pwr_mutex); > + > + /* the unit is microWatt */ > + avg_acc += jdelta[cu]; > + } > + > + return sprintf(buf, "%u\n", (unsigned int) avg_acc); > +} > +static DEVICE_ATTR(power1_acc, S_IRUGO, show_power_acc, NULL);
I am not really a friend of introducing a non-standard attribute. Does the energy attribute not work here ? Thanks, Guenter -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
