/*
- * (C) Copyright 2009-2011 -
- * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * lttng-context-perf-counters.c
*
* LTTng performance monitoring counters (perf-counters) integration module.
*
- * Dual LGPL v2.1/GPL v2 license.
+ * 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/perf_event.h>
#include <linux/list.h>
#include <linux/string.h>
-#include "ltt-events.h"
-#include "wrapper/ringbuffer/frontend_types.h"
-#include "wrapper/vmalloc.h"
-#include "ltt-tracer.h"
-
-/*
- * TODO: Add CPU hotplug support.
- */
-
-static DEFINE_MUTEX(perf_counter_mutex);
-static LIST_HEAD(perf_counter_contexts);
+#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, ltt_alignof(uint64_t));
+ 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 ltt_channel *chan)
+ struct lttng_channel *chan)
{
struct perf_event *event;
uint64_t value;
- event = field->u.perf_counter.e[ctx->cpu];
- event->pmu->read(event);
- value = local64_read(&event->count);
- lib_ring_buffer_align_ctx(ctx, ltt_alignof(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;
- int cpu;
-
- mutex_lock(&perf_counter_mutex);
- list_del(&field->u.perf_counter.head);
- for_each_online_cpu(cpu)
- perf_event_release_kernel(events[cpu]);
- mutex_unlock(&perf_counter_mutex);
+ 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);
- kfree(events);
+ 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;
- int cpu;
char *name_alloc;
- events = kzalloc(num_possible_cpus() * sizeof(*events), GFP_KERNEL);
+ events = lttng_kvzalloc(num_possible_cpus() * sizeof(*events), GFP_KERNEL);
if (!events)
return -ENOMEM;
- attr = kzalloc(sizeof(*field->u.perf_counter.attr), GFP_KERNEL);
+ attr = kzalloc(sizeof(struct perf_event_attr), GFP_KERNEL);
if (!attr) {
ret = -ENOMEM;
goto error_attr;
attr->pinned = 1;
attr->disabled = 0;
- mutex_lock(&perf_counter_mutex);
-
- for_each_online_cpu(cpu) {
- events[cpu] = perf_event_create_kernel_counter(attr,
- cpu, NULL, overflow_callback);
- if (!events[cpu]) {
- ret = -EINVAL;
- goto error;
- }
+ 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 (!field->event_field.name)
+ if (!name_alloc) {
+ ret = -ENOMEM;
goto name_alloc_error;
+ }
field = lttng_append_context(ctx);
if (!field) {
ret = -ENOMEM;
- goto error;
+ 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(unsigned long) * CHAR_BIT;
- field->event_field.type.u.basic.integer.alignment = ltt_alignof(unsigned long) * CHAR_BIT;
- field->event_field.type.u.basic.integer.signedness = is_signed_type(unsigned long);
+ 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.e = events;
- field->u.perf_counter.attr = attr;
-
- list_add(&field->u.perf_counter.head, &perf_counter_contexts);
- mutex_unlock(&perf_counter_mutex);
+ field->u.perf_counter = perf_field;
+ lttng_context_update(*ctx);
wrapper_vmalloc_sync_all();
return 0;
-error:
+#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:
- for_each_online_cpu(cpu) {
- if (events[cpu])
- perf_event_release_kernel(events[cpu]);
- }
- mutex_unlock(&perf_counter_mutex);
+ kfree(perf_field);
+error_alloc_perf_field:
kfree(attr);
error_attr:
- kfree(events);
+ lttng_kvfree(events);
return ret;
}
-
-MODULE_LICENSE("GPL and additional rights");
-MODULE_AUTHOR("Mathieu Desnoyers");
-MODULE_DESCRIPTION("Linux Trace Toolkit Perf Support");
projects / lttng-modules.git / blobdiff