Messages in this thread Patch in this message | | | Date | Fri, 1 Mar 2019 12:42:50 +0100 | From | Jiri Olsa <> | Subject | [RFC] perf/x86/rapl: Getting zero on energy-cores event |
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hi, I'm getting zero counts for energy-cores event on broadwell-x server (model 0x4f)
I checked intel_rapl powercap driver and it won't export the counter if it rdmsr returns zero on it
the SDM also says the rdmsr returns zero for some models
I made changes on perf rapl pmu below to remove sysfs events if their rdmsr returns zero just to ilustrate the case
I think there's probably better fix, but I'm not sure if there's a reason for zero counters to be exposed..?
thoughts? thanks, jirka
--- diff --git a/arch/x86/events/intel/rapl.c b/arch/x86/events/intel/rapl.c index 94dc564146ca..effb9a9d2368 100644 --- a/arch/x86/events/intel/rapl.c +++ b/arch/x86/events/intel/rapl.c @@ -54,6 +54,7 @@ #include <linux/module.h> #include <linux/slab.h> #include <linux/perf_event.h> +#include <linux/nospec.h> #include <asm/cpu_device_id.h> #include <asm/intel-family.h> #include "../perf_event.h" @@ -346,10 +347,18 @@ static void rapl_pmu_event_del(struct perf_event *event, int flags) rapl_pmu_event_stop(event, PERF_EF_UPDATE); } +static unsigned int event_msr[NR_RAPL_DOMAINS] = { + MSR_PP0_ENERGY_STATUS, + MSR_PKG_ENERGY_STATUS, + MSR_DRAM_ENERGY_STATUS, + MSR_PP1_ENERGY_STATUS, + MSR_PLATFORM_ENERGY_STATUS, +}; + static int rapl_pmu_event_init(struct perf_event *event) { u64 cfg = event->attr.config & RAPL_EVENT_MASK; - int bit, msr, ret = 0; + int bit, ret = 0; struct rapl_pmu *pmu; /* only look at RAPL events */ @@ -365,33 +374,12 @@ static int rapl_pmu_event_init(struct perf_event *event) event->event_caps |= PERF_EV_CAP_READ_ACTIVE_PKG; - /* - * check event is known (determines counter) - */ - switch (cfg) { - case INTEL_RAPL_PP0: - bit = RAPL_IDX_PP0_NRG_STAT; - msr = MSR_PP0_ENERGY_STATUS; - break; - case INTEL_RAPL_PKG: - bit = RAPL_IDX_PKG_NRG_STAT; - msr = MSR_PKG_ENERGY_STATUS; - break; - case INTEL_RAPL_RAM: - bit = RAPL_IDX_RAM_NRG_STAT; - msr = MSR_DRAM_ENERGY_STATUS; - break; - case INTEL_RAPL_PP1: - bit = RAPL_IDX_PP1_NRG_STAT; - msr = MSR_PP1_ENERGY_STATUS; - break; - case INTEL_RAPL_PSYS: - bit = RAPL_IDX_PSYS_NRG_STAT; - msr = MSR_PLATFORM_ENERGY_STATUS; - break; - default: + if (!cfg || cfg >= NR_RAPL_DOMAINS) return -EINVAL; - } + + cfg = array_index_nospec(cfg, NR_RAPL_DOMAINS); + bit = cfg - 1; + /* check event supported */ if (!(rapl_cntr_mask & (1 << bit))) return -EINVAL; @@ -406,7 +394,7 @@ static int rapl_pmu_event_init(struct perf_event *event) return -EINVAL; event->cpu = pmu->cpu; event->pmu_private = pmu; - event->hw.event_base = msr; + event->hw.event_base = event_msr[bit]; event->hw.config = cfg; event->hw.idx = bit; @@ -435,11 +423,27 @@ static struct attribute_group rapl_pmu_attr_group = { .attrs = rapl_pmu_attrs, }; -RAPL_EVENT_ATTR_STR(energy-cores, rapl_cores, "event=0x01"); -RAPL_EVENT_ATTR_STR(energy-pkg , rapl_pkg, "event=0x02"); -RAPL_EVENT_ATTR_STR(energy-ram , rapl_ram, "event=0x03"); -RAPL_EVENT_ATTR_STR(energy-gpu , rapl_gpu, "event=0x04"); -RAPL_EVENT_ATTR_STR(energy-psys, rapl_psys, "event=0x05"); +static ssize_t +rapl_event_sysfs_show(struct device *dev, struct device_attribute *attr, + char *page) +{ + struct perf_pmu_events_attr *pmu_attr = + container_of(attr, struct perf_pmu_events_attr, attr); + + return sprintf(page, "event=%llu\n", pmu_attr->id); +} + +#define RAPL_EVENT_ATTR(_name, v, _id) \ +static struct perf_pmu_events_attr event_attr_##v = { \ + .attr = __ATTR(_name, 0444, rapl_event_sysfs_show, NULL), \ + .id = RAPL_IDX_##_id##_NRG_STAT, \ +}; + +RAPL_EVENT_ATTR(energy-cores, rapl_cores, PP0); +RAPL_EVENT_ATTR(energy-pkg , rapl_pkg, PKG); +RAPL_EVENT_ATTR(energy-ram , rapl_ram, RAM); +RAPL_EVENT_ATTR(energy-gpu , rapl_gpu, PP1); +RAPL_EVENT_ATTR(energy-psys , rapl_psys, PSYS); RAPL_EVENT_ATTR_STR(energy-cores.unit, rapl_cores_unit, "Joules"); RAPL_EVENT_ATTR_STR(energy-pkg.unit , rapl_pkg_unit, "Joules"); @@ -780,6 +784,59 @@ static const struct x86_cpu_id rapl_cpu_match[] __initconst = { MODULE_DEVICE_TABLE(x86cpu, rapl_cpu_match); +static void __init remove_name(struct attribute **attrs, const char *name) +{ + struct device_attribute *attr; + int i, j; + + for (i = 0; attrs[i]; i++) { + attr = (struct device_attribute *) attrs[i]; + + if (strncmp(name, attr->attr.name, strlen(name))) + continue; + + for (j = i; attrs[j]; j++) + attrs[j] = attrs[j + 1]; + + /* Check the shifted attr. */ + i--; + } +} + +static void __init check_events(struct attribute **attrs) +{ + struct perf_pmu_events_attr *pmu_attr; + struct device_attribute *attr; + int i, j; + + for (i = 0; attrs[i]; i++) { + u64 val = 0; + u64 bit; + + attr = (struct device_attribute *) attrs[i]; + pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr); + + if (pmu_attr->event_str) + continue; + + bit = pmu_attr->id; + + if (WARN_ON_ONCE(bit >= NR_RAPL_DOMAINS)) + continue; + + if (!rdmsrl_safe(event_msr[bit], &val) && val) + continue; + + remove_name(&attrs[i + 1], attr->attr.name); + + for (j = i; attrs[j]; j++) + attrs[j] = attrs[j + 1]; + + /* Check the shifted attr. */ + i--; + } +} + static int __init rapl_pmu_init(void) { const struct x86_cpu_id *id; @@ -796,6 +853,8 @@ static int __init rapl_pmu_init(void) rapl_cntr_mask = rapl_init->cntr_mask; rapl_pmu_events_group.attrs = rapl_init->attrs; + check_events(rapl_pmu_events_group.attrs); + ret = rapl_check_hw_unit(apply_quirk); if (ret) return ret;
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