+++ /dev/null
-/*
- * lttng-context-perf-counters.c
- *
- * LTTng performance monitoring counters (perf-counters) integration module.
- *
- * Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; only
- * version 2.1 of the License.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#include <linux/module.h>
-#include <linux/slab.h>
-#include <linux/perf_event.h>
-#include <linux/list.h>
-#include <linux/string.h>
-#include <linux/cpu.h>
-#include <lttng-events.h>
-#include <wrapper/ringbuffer/frontend_types.h>
-#include <wrapper/vmalloc.h>
-#include <wrapper/perf.h>
-#include <lttng-tracer.h>
-
-static
-size_t perf_counter_get_size(size_t offset)
-{
- size_t size = 0;
-
- size += lib_ring_buffer_align(offset, lttng_alignof(uint64_t));
- size += sizeof(uint64_t);
- return size;
-}
-
-static
-void perf_counter_record(struct lttng_ctx_field *field,
- struct lib_ring_buffer_ctx *ctx,
- struct lttng_channel *chan)
-{
- struct perf_event *event;
- uint64_t value;
-
- event = field->u.perf_counter->e[ctx->cpu];
- if (likely(event)) {
- if (unlikely(event->state == PERF_EVENT_STATE_ERROR)) {
- value = 0;
- } else {
- event->pmu->read(event);
- value = local64_read(&event->count);
- }
- } else {
- /*
- * Perf chooses not to be clever and not to support enabling a
- * perf counter before the cpu is brought up. Therefore, we need
- * to support having events coming (e.g. scheduler events)
- * before the counter is setup. Write an arbitrary 0 in this
- * case.
- */
- value = 0;
- }
- lib_ring_buffer_align_ctx(ctx, lttng_alignof(value));
- chan->ops->event_write(ctx, &value, sizeof(value));
-}
-
-#if defined(CONFIG_PERF_EVENTS) && (LINUX_VERSION_CODE >= KERNEL_VERSION(3,0,99))
-static
-void overflow_callback(struct perf_event *event,
- struct perf_sample_data *data,
- struct pt_regs *regs)
-{
-}
-#else
-static
-void overflow_callback(struct perf_event *event, int nmi,
- struct perf_sample_data *data,
- struct pt_regs *regs)
-{
-}
-#endif
-
-static
-void lttng_destroy_perf_counter_field(struct lttng_ctx_field *field)
-{
- struct perf_event **events = field->u.perf_counter->e;
-
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
- {
- int ret;
-
- ret = cpuhp_state_remove_instance(lttng_hp_online,
- &field->u.perf_counter->cpuhp_online.node);
- WARN_ON(ret);
- ret = cpuhp_state_remove_instance(lttng_hp_prepare,
- &field->u.perf_counter->cpuhp_prepare.node);
- WARN_ON(ret);
- }
-#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
- {
- int cpu;
-
- get_online_cpus();
- for_each_online_cpu(cpu)
- perf_event_release_kernel(events[cpu]);
- put_online_cpus();
-#ifdef CONFIG_HOTPLUG_CPU
- unregister_cpu_notifier(&field->u.perf_counter->nb);
-#endif
- }
-#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
- kfree(field->event_field.name);
- kfree(field->u.perf_counter->attr);
- lttng_kvfree(events);
- kfree(field->u.perf_counter);
-}
-
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
-
-int lttng_cpuhp_perf_counter_online(unsigned int cpu,
- struct lttng_cpuhp_node *node)
-{
- struct lttng_perf_counter_field *perf_field =
- container_of(node, struct lttng_perf_counter_field,
- cpuhp_online);
- struct perf_event **events = perf_field->e;
- struct perf_event_attr *attr = perf_field->attr;
- struct perf_event *pevent;
-
- pevent = wrapper_perf_event_create_kernel_counter(attr,
- cpu, NULL, overflow_callback);
- if (!pevent || IS_ERR(pevent))
- return -EINVAL;
- if (pevent->state == PERF_EVENT_STATE_ERROR) {
- perf_event_release_kernel(pevent);
- return -EINVAL;
- }
- barrier(); /* Create perf counter before setting event */
- events[cpu] = pevent;
- return 0;
-}
-
-int lttng_cpuhp_perf_counter_dead(unsigned int cpu,
- struct lttng_cpuhp_node *node)
-{
- struct lttng_perf_counter_field *perf_field =
- container_of(node, struct lttng_perf_counter_field,
- cpuhp_prepare);
- struct perf_event **events = perf_field->e;
- struct perf_event *pevent;
-
- pevent = events[cpu];
- events[cpu] = NULL;
- barrier(); /* NULLify event before perf counter teardown */
- perf_event_release_kernel(pevent);
- return 0;
-}
-
-#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
-
-#ifdef CONFIG_HOTPLUG_CPU
-
-/**
- * lttng_perf_counter_hp_callback - CPU hotplug callback
- * @nb: notifier block
- * @action: hotplug action to take
- * @hcpu: CPU number
- *
- * Returns the success/failure of the operation. (%NOTIFY_OK, %NOTIFY_BAD)
- *
- * We can setup perf counters when the cpu is online (up prepare seems to be too
- * soon).
- */
-static
-int lttng_perf_counter_cpu_hp_callback(struct notifier_block *nb,
- unsigned long action,
- void *hcpu)
-{
- unsigned int cpu = (unsigned long) hcpu;
- struct lttng_perf_counter_field *perf_field =
- container_of(nb, struct lttng_perf_counter_field, nb);
- struct perf_event **events = perf_field->e;
- struct perf_event_attr *attr = perf_field->attr;
- struct perf_event *pevent;
-
- if (!perf_field->hp_enable)
- return NOTIFY_OK;
-
- switch (action) {
- case CPU_ONLINE:
- case CPU_ONLINE_FROZEN:
- pevent = wrapper_perf_event_create_kernel_counter(attr,
- cpu, NULL, overflow_callback);
- if (!pevent || IS_ERR(pevent))
- return NOTIFY_BAD;
- if (pevent->state == PERF_EVENT_STATE_ERROR) {
- perf_event_release_kernel(pevent);
- return NOTIFY_BAD;
- }
- barrier(); /* Create perf counter before setting event */
- events[cpu] = pevent;
- break;
- case CPU_UP_CANCELED:
- case CPU_UP_CANCELED_FROZEN:
- case CPU_DEAD:
- case CPU_DEAD_FROZEN:
- pevent = events[cpu];
- events[cpu] = NULL;
- barrier(); /* NULLify event before perf counter teardown */
- perf_event_release_kernel(pevent);
- break;
- }
- return NOTIFY_OK;
-}
-
-#endif
-
-#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
-
-int lttng_add_perf_counter_to_ctx(uint32_t type,
- uint64_t config,
- const char *name,
- struct lttng_ctx **ctx)
-{
- struct lttng_ctx_field *field;
- struct lttng_perf_counter_field *perf_field;
- struct perf_event **events;
- struct perf_event_attr *attr;
- int ret;
- char *name_alloc;
-
- events = lttng_kvzalloc(num_possible_cpus() * sizeof(*events), GFP_KERNEL);
- if (!events)
- return -ENOMEM;
-
- attr = kzalloc(sizeof(struct perf_event_attr), GFP_KERNEL);
- if (!attr) {
- ret = -ENOMEM;
- goto error_attr;
- }
-
- attr->type = type;
- attr->config = config;
- attr->size = sizeof(struct perf_event_attr);
- attr->pinned = 1;
- attr->disabled = 0;
-
- perf_field = kzalloc(sizeof(struct lttng_perf_counter_field), GFP_KERNEL);
- if (!perf_field) {
- ret = -ENOMEM;
- goto error_alloc_perf_field;
- }
- perf_field->e = events;
- perf_field->attr = attr;
-
- name_alloc = kstrdup(name, GFP_KERNEL);
- if (!name_alloc) {
- ret = -ENOMEM;
- goto name_alloc_error;
- }
-
- field = lttng_append_context(ctx);
- if (!field) {
- ret = -ENOMEM;
- goto append_context_error;
- }
- if (lttng_find_context(*ctx, name_alloc)) {
- ret = -EEXIST;
- goto find_error;
- }
-
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
-
- perf_field->cpuhp_prepare.component = LTTNG_CONTEXT_PERF_COUNTERS;
- ret = cpuhp_state_add_instance(lttng_hp_prepare,
- &perf_field->cpuhp_prepare.node);
- if (ret)
- goto cpuhp_prepare_error;
-
- perf_field->cpuhp_online.component = LTTNG_CONTEXT_PERF_COUNTERS;
- ret = cpuhp_state_add_instance(lttng_hp_online,
- &perf_field->cpuhp_online.node);
- if (ret)
- goto cpuhp_online_error;
-
-#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
- {
- int cpu;
-
-#ifdef CONFIG_HOTPLUG_CPU
- perf_field->nb.notifier_call =
- lttng_perf_counter_cpu_hp_callback;
- perf_field->nb.priority = 0;
- register_cpu_notifier(&perf_field->nb);
-#endif
- get_online_cpus();
- for_each_online_cpu(cpu) {
- events[cpu] = wrapper_perf_event_create_kernel_counter(attr,
- cpu, NULL, overflow_callback);
- if (!events[cpu] || IS_ERR(events[cpu])) {
- ret = -EINVAL;
- goto counter_error;
- }
- if (events[cpu]->state == PERF_EVENT_STATE_ERROR) {
- ret = -EBUSY;
- goto counter_busy;
- }
- }
- put_online_cpus();
- perf_field->hp_enable = 1;
- }
-#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
-
- field->destroy = lttng_destroy_perf_counter_field;
-
- field->event_field.name = name_alloc;
- field->event_field.type.atype = atype_integer;
- field->event_field.type.u.basic.integer.size = sizeof(uint64_t) * CHAR_BIT;
- field->event_field.type.u.basic.integer.alignment = lttng_alignof(uint64_t) * CHAR_BIT;
- field->event_field.type.u.basic.integer.signedness = lttng_is_signed_type(uint64_t);
- field->event_field.type.u.basic.integer.reverse_byte_order = 0;
- field->event_field.type.u.basic.integer.base = 10;
- field->event_field.type.u.basic.integer.encoding = lttng_encode_none;
- field->get_size = perf_counter_get_size;
- field->record = perf_counter_record;
- field->u.perf_counter = perf_field;
- lttng_context_update(*ctx);
-
- wrapper_vmalloc_sync_all();
- return 0;
-
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
-cpuhp_online_error:
- {
- int remove_ret;
-
- remove_ret = cpuhp_state_remove_instance(lttng_hp_prepare,
- &perf_field->cpuhp_prepare.node);
- WARN_ON(remove_ret);
- }
-cpuhp_prepare_error:
-#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
-counter_busy:
-counter_error:
- {
- int cpu;
-
- for_each_online_cpu(cpu) {
- if (events[cpu] && !IS_ERR(events[cpu]))
- perf_event_release_kernel(events[cpu]);
- }
- put_online_cpus();
-#ifdef CONFIG_HOTPLUG_CPU
- unregister_cpu_notifier(&perf_field->nb);
-#endif
- }
-#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
-find_error:
- lttng_remove_context_field(ctx, field);
-append_context_error:
- kfree(name_alloc);
-name_alloc_error:
- kfree(perf_field);
-error_alloc_perf_field:
- kfree(attr);
-error_attr:
- lttng_kvfree(events);
- return ret;
-}
projects / lttng-modules.git / blobdiff