From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bh-25.webhostbox.net ([208.91.199.152]:33632 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753059AbcDFPaf (ORCPT ); Wed, 6 Apr 2016 11:30:35 -0400 Date: Wed, 6 Apr 2016 08:30:25 -0700 From: Guenter Roeck To: Huang Rui Cc: Jean Delvare , linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org, Borislav Petkov , Sherry Hurwitz Subject: Re: [PATCH v6 2/6] hwmon: (fam15h_power) Add compute unit accumulated power Message-ID: <20160406153025.GA16343@roeck-us.net> References: <1459928655-6071-1-git-send-email-ray.huang@amd.com> <1459928655-6071-3-git-send-email-ray.huang@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1459928655-6071-3-git-send-email-ray.huang@amd.com> Sender: linux-hwmon-owner@vger.kernel.org List-Id: linux-hwmon@vger.kernel.org On Wed, Apr 06, 2016 at 03:44:11PM +0800, Huang Rui wrote: > This patch adds a member in fam15h_power_data which specifies the > compute unit accumulated power. It adds do_read_registers_on_cu to do > all the read to all MSRs and run it on one of the online cores on each > compute unit with smp_call_function_many(). This behavior can decrease > IPI numbers. > > Suggested-by: Borislav Petkov > Signed-off-by: Huang Rui > --- > drivers/hwmon/fam15h_power.c | 72 +++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 71 insertions(+), 1 deletion(-) > > diff --git a/drivers/hwmon/fam15h_power.c b/drivers/hwmon/fam15h_power.c > index 4f695d8..4edbaf0 100644 > --- a/drivers/hwmon/fam15h_power.c > +++ b/drivers/hwmon/fam15h_power.c > @@ -25,6 +25,8 @@ > #include > #include > #include > +#include > +#include > #include > #include > > @@ -44,7 +46,9 @@ MODULE_LICENSE("GPL"); > > #define FAM15H_MIN_NUM_ATTRS 2 > #define FAM15H_NUM_GROUPS 2 > +#define MAX_CUS 8 > > +#define MSR_F15H_CU_PWR_ACCUMULATOR 0xc001007a > #define MSR_F15H_CU_MAX_PWR_ACCUMULATOR 0xc001007b > > #define PCI_DEVICE_ID_AMD_15H_M70H_NB_F4 0x15b4 > @@ -59,6 +63,8 @@ struct fam15h_power_data { > struct attribute_group group; > /* maximum accumulated power of a compute unit */ > u64 max_cu_acc_power; > + /* accumulated power of the compute units */ > + u64 cu_acc_power[MAX_CUS]; > }; > > static ssize_t show_power(struct device *dev, > @@ -125,6 +131,70 @@ static ssize_t show_power_crit(struct device *dev, > } > static DEVICE_ATTR(power1_crit, S_IRUGO, show_power_crit, NULL); > > +static void do_read_registers_on_cu(void *_data) > +{ > + struct fam15h_power_data *data = _data; > + int cpu, cu; > + > + cpu = smp_processor_id(); > + Is this function now defined in non-SMP code ? If so, can you point me to the patch or branch introducing it ? It doesn't seem to be in mainline or in -next unless I am missing it. > + /* > + * With the new x86 topology modelling, cpu core id actually > + * is compute unit id. > + */ > + cu = cpu_data(cpu).cpu_core_id; > + > + rdmsrl_safe(MSR_F15H_CU_PWR_ACCUMULATOR, &data->cu_acc_power[cu]); > +} > + > +/* > + * This function is only able to be called when CPUID > + * Fn8000_0007:EDX[12] is set. > + */ > +static int read_registers(struct fam15h_power_data *data) > +{ > + int this_cpu, ret, cpu; > + int core, this_core; > + cpumask_var_t mask; > + > + ret = zalloc_cpumask_var(&mask, GFP_KERNEL); > + if (!ret) > + return -ENOMEM; > + > + get_online_cpus(); > + this_cpu = smp_processor_id(); > + > + /* > + * Choose the first online core of each compute unit, and then > + * read their MSR value of power and ptsc in a single IPI, > + * because the MSR value of CPU core represent the compute > + * unit's. > + */ > + core = -1; > + > + for_each_online_cpu(cpu) { > + this_core = topology_core_id(cpu); > + > + if (this_core == core) > + continue; > + > + core = this_core; > + Sorry if I missed some context - is it guaranteed that all cores in the same compute unit are returned next to each other from for_each_online_cpu() ? Thanks, Guenter > + /* get any CPU on this compute unit */ > + cpumask_set_cpu(cpumask_any(topology_sibling_cpumask(cpu)), mask); > + } > + > + if (cpumask_test_cpu(this_cpu, mask)) > + do_read_registers_on_cu(data); > + > + smp_call_function_many(mask, do_read_registers_on_cu, data, true); > + put_online_cpus(); > + > + free_cpumask_var(mask); > + > + return 0; > +} > + > static int fam15h_power_init_attrs(struct pci_dev *pdev, > struct fam15h_power_data *data) > { > @@ -263,7 +333,7 @@ static int fam15h_power_init_data(struct pci_dev *f4, > > data->max_cu_acc_power = tmp; > > - return 0; > + return read_registers(data); > } > > static int fam15h_power_probe(struct pci_dev *pdev, > -- > 1.9.1 >