[lttng-modules.git] / lttng-context-perf-counters.c

/*
 * 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);
	kfree(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 = kzalloc(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:
	kfree(events);
	return ret;
}
Commit	Line	Data
833ad6a0	1	/*
886d51a3	2	* lttng-context-perf-counters.c
833ad6a0 MD	3	*
	4	* LTTng performance monitoring counters (perf-counters) integration module.
	5	*
886d51a3 MD	6	* Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	7	*
	8	* This library is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU Lesser General Public
	10	* License as published by the Free Software Foundation; only
	11	* version 2.1 of the License.
	12	*
	13	* This library is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	16	* Lesser General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU Lesser General Public
	19	* License along with this library; if not, write to the Free Software
	20	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
833ad6a0 MD	21	*/
	22
	23	#include <linux/module.h>
	24	#include <linux/slab.h>
	25	#include <linux/perf_event.h>
	26	#include <linux/list.h>
c24a0d71	27	#include <linux/string.h>
5ca7b8a3	28	#include <linux/cpu.h>
241ae9a8 MD	29	#include <lttng-events.h>
	30	#include <wrapper/ringbuffer/frontend_types.h>
	31	#include <wrapper/vmalloc.h>
	32	#include <wrapper/perf.h>
	33	#include <lttng-tracer.h>
833ad6a0	34
f1676205 MD	35	static
	36	size_t perf_counter_get_size(size_t offset)
	37	{
	38	size_t size = 0;
	39
a90917c3	40	size += lib_ring_buffer_align(offset, lttng_alignof(uint64_t));
f1676205 MD	41	size += sizeof(uint64_t);
	42	return size;
	43	}
	44
833ad6a0 MD	45	static
	46	void perf_counter_record(struct lttng_ctx_field *field,
	47	struct lib_ring_buffer_ctx *ctx,
a90917c3	48	struct lttng_channel *chan)
833ad6a0 MD	49	{
	50	struct perf_event *event;
	51	uint64_t value;
	52
2001023e	53	event = field->u.perf_counter->e[ctx->cpu];
0478c519	54	if (likely(event)) {
7b745a96 MD	55	if (unlikely(event->state == PERF_EVENT_STATE_ERROR)) {
	56	value = 0;
	57	} else {
	58	event->pmu->read(event);
	59	value = local64_read(&event->count);
	60	}
f91fd73b MD	61	} else {
	62	/*
	63	* Perf chooses not to be clever and not to support enabling a
	64	* perf counter before the cpu is brought up. Therefore, we need
	65	* to support having events coming (e.g. scheduler events)
	66	* before the counter is setup. Write an arbitrary 0 in this
	67	* case.
	68	*/
	69	value = 0;
	70	}
a90917c3	71	lib_ring_buffer_align_ctx(ctx, lttng_alignof(value));
833ad6a0 MD	72	chan->ops->event_write(ctx, &value, sizeof(value));
	73	}
	74
90f5546c MD	75	#if defined(CONFIG_PERF_EVENTS) && (LINUX_VERSION_CODE >= KERNEL_VERSION(3,0,99))
	76	static
	77	void overflow_callback(struct perf_event *event,
	78	struct perf_sample_data *data,
	79	struct pt_regs *regs)
	80	{
	81	}
	82	#else
833ad6a0 MD	83	static
	84	void overflow_callback(struct perf_event *event, int nmi,
	85	struct perf_sample_data *data,
	86	struct pt_regs *regs)
	87	{
	88	}
90f5546c	89	#endif
833ad6a0	90
2dccf128 MD	91	static
	92	void lttng_destroy_perf_counter_field(struct lttng_ctx_field *field)
	93	{
2001023e	94	struct perf_event **events = field->u.perf_counter->e;
2dccf128	95
8a30119b MD	96	#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
	97	{
	98	int ret;
	99
	100	ret = cpuhp_state_remove_instance(lttng_hp_online,
	101	&field->u.perf_counter->cpuhp_online.node);
	102	WARN_ON(ret);
	103	ret = cpuhp_state_remove_instance(lttng_hp_prepare,
	104	&field->u.perf_counter->cpuhp_prepare.node);
	105	WARN_ON(ret);
	106	}
	107	#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
	108	{
	109	int cpu;
	110
	111	get_online_cpus();
	112	for_each_online_cpu(cpu)
	113	perf_event_release_kernel(events[cpu]);
	114	put_online_cpus();
8289661d	115	#ifdef CONFIG_HOTPLUG_CPU
8a30119b	116	unregister_cpu_notifier(&field->u.perf_counter->nb);
8289661d	117	#endif
8a30119b MD	118	}
8a30119b MD	119	#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
c24a0d71	120	kfree(field->event_field.name);
2001023e	121	kfree(field->u.perf_counter->attr);
2dccf128	122	kfree(events);
2001023e	123	kfree(field->u.perf_counter);
2dccf128 MD	124	}
2dccf128 MD	125
8a30119b MD	126	#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
	127
	128	int lttng_cpuhp_perf_counter_online(unsigned int cpu,
	129	struct lttng_cpuhp_node *node)
	130	{
	131	struct lttng_perf_counter_field *perf_field =
	132	container_of(node, struct lttng_perf_counter_field,
	133	cpuhp_online);
	134	struct perf_event **events = perf_field->e;
	135	struct perf_event_attr *attr = perf_field->attr;
	136	struct perf_event *pevent;
	137
	138	pevent = wrapper_perf_event_create_kernel_counter(attr,
	139	cpu, NULL, overflow_callback);
	140	if (!pevent \|\| IS_ERR(pevent))
	141	return -EINVAL;
	142	if (pevent->state == PERF_EVENT_STATE_ERROR) {
	143	perf_event_release_kernel(pevent);
	144	return -EINVAL;
	145	}
	146	barrier(); /* Create perf counter before setting event */
	147	events[cpu] = pevent;
	148	return 0;
	149	}
	150
	151	int lttng_cpuhp_perf_counter_dead(unsigned int cpu,
	152	struct lttng_cpuhp_node *node)
	153	{
	154	struct lttng_perf_counter_field *perf_field =
	155	container_of(node, struct lttng_perf_counter_field,
	156	cpuhp_prepare);
	157	struct perf_event **events = perf_field->e;
	158	struct perf_event *pevent;
	159
	160	pevent = events[cpu];
	161	events[cpu] = NULL;
	162	barrier(); /* NULLify event before perf counter teardown */
	163	perf_event_release_kernel(pevent);
	164	return 0;
	165	}
	166
	167	#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
	168
8289661d MD	169	#ifdef CONFIG_HOTPLUG_CPU
	170
	171	/**
	172	* lttng_perf_counter_hp_callback - CPU hotplug callback
	173	* @nb: notifier block
	174	* @action: hotplug action to take
	175	* @hcpu: CPU number
	176	*
	177	* Returns the success/failure of the operation. (%NOTIFY_OK, %NOTIFY_BAD)
	178	*
	179	* We can setup perf counters when the cpu is online (up prepare seems to be too
	180	* soon).
	181	*/
	182	static
e8f071d5	183	int lttng_perf_counter_cpu_hp_callback(struct notifier_block *nb,
8289661d MD	184	unsigned long action,
	185	void *hcpu)
	186	{
	187	unsigned int cpu = (unsigned long) hcpu;
2001023e MD	188	struct lttng_perf_counter_field *perf_field =
	189	container_of(nb, struct lttng_perf_counter_field, nb);
	190	struct perf_event **events = perf_field->e;
	191	struct perf_event_attr *attr = perf_field->attr;
f91fd73b	192	struct perf_event *pevent;
8289661d	193
2001023e	194	if (!perf_field->hp_enable)
8289661d MD	195	return NOTIFY_OK;
	196
	197	switch (action) {
	198	case CPU_ONLINE:
	199	case CPU_ONLINE_FROZEN:
90f5546c	200	pevent = wrapper_perf_event_create_kernel_counter(attr,
8289661d	201	cpu, NULL, overflow_callback);
0478c519	202	if (!pevent \|\| IS_ERR(pevent))
8289661d	203	return NOTIFY_BAD;
7b745a96 MD	204	if (pevent->state == PERF_EVENT_STATE_ERROR) {
	205	perf_event_release_kernel(pevent);
	206	return NOTIFY_BAD;
	207	}
f91fd73b MD	208	barrier(); /* Create perf counter before setting event */
f91fd73b MD	209	events[cpu] = pevent;
8289661d MD	210	break;
	211	case CPU_UP_CANCELED:
	212	case CPU_UP_CANCELED_FROZEN:
	213	case CPU_DEAD:
	214	case CPU_DEAD_FROZEN:
f91fd73b MD	215	pevent = events[cpu];
	216	events[cpu] = NULL;
	217	barrier(); /* NULLify event before perf counter teardown */
	218	perf_event_release_kernel(pevent);
8289661d MD	219	break;
	220	}
	221	return NOTIFY_OK;
	222	}
	223
	224	#endif
	225
8a30119b MD	226	#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
8a30119b MD	227
833ad6a0 MD	228	int lttng_add_perf_counter_to_ctx(uint32_t type,
833ad6a0 MD	229	uint64_t config,
c24a0d71	230	const char *name,
2dccf128	231	struct lttng_ctx **ctx)
833ad6a0 MD	232	{
833ad6a0 MD	233	struct lttng_ctx_field *field;
2001023e	234	struct lttng_perf_counter_field *perf_field;
833ad6a0 MD	235	struct perf_event **events;
	236	struct perf_event_attr *attr;
	237	int ret;
c24a0d71	238	char *name_alloc;
833ad6a0 MD	239
	240	events = kzalloc(num_possible_cpus() * sizeof(*events), GFP_KERNEL);
	241	if (!events)
	242	return -ENOMEM;
	243
2001023e	244	attr = kzalloc(sizeof(struct perf_event_attr), GFP_KERNEL);
833ad6a0 MD	245	if (!attr) {
	246	ret = -ENOMEM;
	247	goto error_attr;
	248	}
	249
	250	attr->type = type;
	251	attr->config = config;
	252	attr->size = sizeof(struct perf_event_attr);
	253	attr->pinned = 1;
	254	attr->disabled = 0;
	255
2001023e MD	256	perf_field = kzalloc(sizeof(struct lttng_perf_counter_field), GFP_KERNEL);
	257	if (!perf_field) {
	258	ret = -ENOMEM;
	259	goto error_alloc_perf_field;
	260	}
	261	perf_field->e = events;
	262	perf_field->attr = attr;
	263
c24a0d71	264	name_alloc = kstrdup(name, GFP_KERNEL);
bef96e48 MD	265	if (!name_alloc) {
bef96e48 MD	266	ret = -ENOMEM;
c24a0d71	267	goto name_alloc_error;
bef96e48	268	}
c24a0d71	269
2dccf128 MD	270	field = lttng_append_context(ctx);
	271	if (!field) {
	272	ret = -ENOMEM;
8289661d	273	goto append_context_error;
833ad6a0	274	}
2001023e	275	if (lttng_find_context(*ctx, name_alloc)) {
44252f0f MD	276	ret = -EEXIST;
	277	goto find_error;
	278	}
8289661d	279
8a30119b MD	280	#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
	281
	282	perf_field->cpuhp_prepare.component = LTTNG_CONTEXT_PERF_COUNTERS;
	283	ret = cpuhp_state_add_instance(lttng_hp_prepare,
	284	&perf_field->cpuhp_prepare.node);
	285	if (ret)
	286	goto cpuhp_prepare_error;
	287
	288	perf_field->cpuhp_online.component = LTTNG_CONTEXT_PERF_COUNTERS;
	289	ret = cpuhp_state_add_instance(lttng_hp_online,
	290	&perf_field->cpuhp_online.node);
	291	if (ret)
	292	goto cpuhp_online_error;
	293
	294	#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
	295	{
	296	int cpu;
	297
8289661d	298	#ifdef CONFIG_HOTPLUG_CPU
8a30119b MD	299	perf_field->nb.notifier_call =
	300	lttng_perf_counter_cpu_hp_callback;
	301	perf_field->nb.priority = 0;
	302	register_cpu_notifier(&perf_field->nb);
8289661d	303	#endif
8a30119b MD	304	get_online_cpus();
	305	for_each_online_cpu(cpu) {
	306	events[cpu] = wrapper_perf_event_create_kernel_counter(attr,
	307	cpu, NULL, overflow_callback);
	308	if (!events[cpu] \|\| IS_ERR(events[cpu])) {
	309	ret = -EINVAL;
	310	goto counter_error;
	311	}
	312	if (events[cpu]->state == PERF_EVENT_STATE_ERROR) {
	313	ret = -EBUSY;
	314	goto counter_busy;
	315	}
7b745a96	316	}
8a30119b MD	317	put_online_cpus();
8a30119b MD	318	perf_field->hp_enable = 1;
8289661d	319	}
8a30119b	320	#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
8289661d	321
2dccf128	322	field->destroy = lttng_destroy_perf_counter_field;
833ad6a0	323
c24a0d71	324	field->event_field.name = name_alloc;
8070f5c0	325	field->event_field.type.atype = atype_integer;
9d7d747f	326	field->event_field.type.u.basic.integer.size = sizeof(uint64_t) * CHAR_BIT;
a90917c3	327	field->event_field.type.u.basic.integer.alignment = lttng_alignof(uint64_t) * CHAR_BIT;
06254b0f	328	field->event_field.type.u.basic.integer.signedness = lttng_is_signed_type(uint64_t);
8070f5c0 MD	329	field->event_field.type.u.basic.integer.reverse_byte_order = 0;
	330	field->event_field.type.u.basic.integer.base = 10;
	331	field->event_field.type.u.basic.integer.encoding = lttng_encode_none;
f1676205 MD	332	field->get_size = perf_counter_get_size;
f1676205 MD	333	field->record = perf_counter_record;
2001023e	334	field->u.perf_counter = perf_field;
a9dd15da	335	lttng_context_update(*ctx);
833ad6a0 MD	336
	337	wrapper_vmalloc_sync_all();
	338	return 0;
	339
8a30119b MD	340	#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
	341	cpuhp_online_error:
	342	{
	343	int remove_ret;
	344
	345	remove_ret = cpuhp_state_remove_instance(lttng_hp_prepare,
	346	&perf_field->cpuhp_prepare.node);
	347	WARN_ON(remove_ret);
	348	}
	349	cpuhp_prepare_error:
	350	#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
7b745a96	351	counter_busy:
8289661d	352	counter_error:
f23d3165 MD	353	{
	354	int cpu;
	355
	356	for_each_online_cpu(cpu) {
	357	if (events[cpu] && !IS_ERR(events[cpu]))
	358	perf_event_release_kernel(events[cpu]);
	359	}
	360	put_online_cpus();
8289661d	361	#ifdef CONFIG_HOTPLUG_CPU
f23d3165	362	unregister_cpu_notifier(&perf_field->nb);
8289661d	363	#endif
f23d3165	364	}
8a30119b	365	#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
44252f0f	366	find_error:
8289661d MD	367	lttng_remove_context_field(ctx, field);
	368	append_context_error:
	369	kfree(name_alloc);
	370	name_alloc_error:
2001023e MD	371	kfree(perf_field);
2001023e MD	372	error_alloc_perf_field:
833ad6a0 MD	373	kfree(attr);
	374	error_attr:
	375	kfree(events);
	376	return ret;
	377	}