From abe43400579d5de0078c2d3a760e6598e183f871 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 17 Nov 2010 23:17:37 +0100 Subject: perf: Sysfs enumeration Simple sysfs emumeration of the PMUs. Use a "event_source" bus, and add PMU devices using their name. Each PMU device has a type attribute which contrains the value needed for perf_event_attr::type to identify this PMU. This is the minimal stub needed to start using this interface, we'll consider extending the sysfs usage later. Cc: Kay Sievers Cc: Greg KH Signed-off-by: Peter Zijlstra LKML-Reference: <20101117222056.316982569@chello.nl> Signed-off-by: Ingo Molnar --- kernel/perf_event.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 94 insertions(+), 1 deletion(-) (limited to 'kernel/perf_event.c') diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 8f09bc877a30..11847bf1e8cc 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include #include @@ -5308,6 +5309,58 @@ out: } static struct idr pmu_idr; +static ssize_t +type_show(struct device *dev, struct device_attribute *attr, char *page) +{ + struct pmu *pmu = dev_get_drvdata(dev); + + return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->type); +} + +static struct device_attribute pmu_dev_attrs[] = { + __ATTR_RO(type), + __ATTR_NULL, +}; + +static int pmu_bus_running; +static struct bus_type pmu_bus = { + .name = "event_source", + .dev_attrs = pmu_dev_attrs, +}; + +static void pmu_dev_release(struct device *dev) +{ + kfree(dev); +} + +static int pmu_dev_alloc(struct pmu *pmu) +{ + int ret = -ENOMEM; + + pmu->dev = kzalloc(sizeof(struct device), GFP_KERNEL); + if (!pmu->dev) + goto out; + + device_initialize(pmu->dev); + ret = dev_set_name(pmu->dev, "%s", pmu->name); + if (ret) + goto free_dev; + + dev_set_drvdata(pmu->dev, pmu); + pmu->dev->bus = &pmu_bus; + pmu->dev->release = pmu_dev_release; + ret = device_add(pmu->dev); + if (ret) + goto free_dev; + +out: + return ret; + +free_dev: + put_device(pmu->dev); + goto out; +} + int perf_pmu_register(struct pmu *pmu, char *name, int type) { int cpu, ret; @@ -5336,6 +5389,12 @@ int perf_pmu_register(struct pmu *pmu, char *name, int type) } pmu->type = type; + if (pmu_bus_running) { + ret = pmu_dev_alloc(pmu); + if (ret) + goto free_idr; + } + skip_type: pmu->pmu_cpu_context = find_pmu_context(pmu->task_ctx_nr); if (pmu->pmu_cpu_context) @@ -5343,7 +5402,7 @@ skip_type: pmu->pmu_cpu_context = alloc_percpu(struct perf_cpu_context); if (!pmu->pmu_cpu_context) - goto free_ird; + goto free_dev; for_each_possible_cpu(cpu) { struct perf_cpu_context *cpuctx; @@ -5387,6 +5446,10 @@ unlock: return ret; +free_dev: + device_del(pmu->dev); + put_device(pmu->dev); + free_idr: if (pmu->type >= PERF_TYPE_MAX) idr_remove(&pmu_idr, pmu->type); @@ -5412,6 +5475,8 @@ void perf_pmu_unregister(struct pmu *pmu) free_percpu(pmu->pmu_disable_count); if (pmu->type >= PERF_TYPE_MAX) idr_remove(&pmu_idr, pmu->type); + device_del(pmu->dev); + put_device(pmu->dev); free_pmu_context(pmu); } @@ -6603,3 +6668,31 @@ void __init perf_event_init(void) ret = init_hw_breakpoint(); WARN(ret, "hw_breakpoint initialization failed with: %d", ret); } + +static int __init perf_event_sysfs_init(void) +{ + struct pmu *pmu; + int ret; + + mutex_lock(&pmus_lock); + + ret = bus_register(&pmu_bus); + if (ret) + goto unlock; + + list_for_each_entry(pmu, &pmus, entry) { + if (!pmu->name || pmu->type < 0) + continue; + + ret = pmu_dev_alloc(pmu); + WARN(ret, "Failed to register pmu: %s, reason %d\n", pmu->name, ret); + } + pmu_bus_running = 1; + ret = 0; + +unlock: + mutex_unlock(&pmus_lock); + + return ret; +} +device_initcall(perf_event_sysfs_init); -- cgit v1.2.3