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

/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
 *
 * lttng-context-perf-counters.c
 *
 * LTTng performance monitoring counters (perf-counters) integration module.
 *
 * Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 */

#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 <linux/mm.h>
#include <lttng-events.h>
#include <wrapper/ringbuffer/frontend_types.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);
	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 = perf_event_create_kernel_counter(attr,
			cpu, NULL, overflow_callback, NULL);
	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 = perf_event_create_kernel_counter(attr,
				cpu, NULL, overflow_callback, NULL);
		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 = 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] = perf_event_create_kernel_counter(attr,
						cpu, NULL, overflow_callback, NULL);
			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.integer.size = sizeof(uint64_t) * CHAR_BIT;
	field->event_field.type.u.integer.alignment = lttng_alignof(uint64_t) * CHAR_BIT;
	field->event_field.type.u.integer.signedness = lttng_is_signed_type(uint64_t);
	field->event_field.type.u.integer.reverse_byte_order = 0;
	field->event_field.type.u.integer.base = 10;
	field->event_field.type.u.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);

	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:
	kvfree(events);
	return ret;
}
Commit	Line	Data
b7cdc182	1	/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
9f36eaed	2	*
886d51a3	3	* lttng-context-perf-counters.c
833ad6a0 MD	4	*
	5	* LTTng performance monitoring counters (perf-counters) integration module.
	6	*
886d51a3	7	* Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
833ad6a0 MD	8	*/
	9
	10	#include <linux/module.h>
	11	#include <linux/slab.h>
	12	#include <linux/perf_event.h>
	13	#include <linux/list.h>
c24a0d71	14	#include <linux/string.h>
5ca7b8a3	15	#include <linux/cpu.h>
c50bdba2	16	#include <linux/mm.h>
241ae9a8 MD	17	#include <lttng-events.h>
241ae9a8 MD	18	#include <wrapper/ringbuffer/frontend_types.h>
241ae9a8	19	#include <lttng-tracer.h>
833ad6a0	20
f1676205 MD	21	static
	22	size_t perf_counter_get_size(size_t offset)
	23	{
	24	size_t size = 0;
	25
a90917c3	26	size += lib_ring_buffer_align(offset, lttng_alignof(uint64_t));
f1676205 MD	27	size += sizeof(uint64_t);
	28	return size;
	29	}
	30
833ad6a0 MD	31	static
	32	void perf_counter_record(struct lttng_ctx_field *field,
	33	struct lib_ring_buffer_ctx *ctx,
a90917c3	34	struct lttng_channel *chan)
833ad6a0 MD	35	{
	36	struct perf_event *event;
	37	uint64_t value;
	38
2001023e	39	event = field->u.perf_counter->e[ctx->cpu];
0478c519	40	if (likely(event)) {
7b745a96 MD	41	if (unlikely(event->state == PERF_EVENT_STATE_ERROR)) {
	42	value = 0;
	43	} else {
	44	event->pmu->read(event);
	45	value = local64_read(&event->count);
	46	}
f91fd73b MD	47	} else {
	48	/*
	49	* Perf chooses not to be clever and not to support enabling a
	50	* perf counter before the cpu is brought up. Therefore, we need
	51	* to support having events coming (e.g. scheduler events)
	52	* before the counter is setup. Write an arbitrary 0 in this
	53	* case.
	54	*/
	55	value = 0;
	56	}
a90917c3	57	lib_ring_buffer_align_ctx(ctx, lttng_alignof(value));
833ad6a0 MD	58	chan->ops->event_write(ctx, &value, sizeof(value));
	59	}
	60
90f5546c MD	61	#if defined(CONFIG_PERF_EVENTS) && (LINUX_VERSION_CODE >= KERNEL_VERSION(3,0,99))
	62	static
	63	void overflow_callback(struct perf_event *event,
	64	struct perf_sample_data *data,
	65	struct pt_regs *regs)
	66	{
	67	}
	68	#else
833ad6a0 MD	69	static
	70	void overflow_callback(struct perf_event *event, int nmi,
	71	struct perf_sample_data *data,
	72	struct pt_regs *regs)
	73	{
	74	}
90f5546c	75	#endif
833ad6a0	76
2dccf128 MD	77	static
	78	void lttng_destroy_perf_counter_field(struct lttng_ctx_field *field)
	79	{
2001023e	80	struct perf_event **events = field->u.perf_counter->e;
2dccf128	81
1e367326 MD	82	#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
	83	{
	84	int ret;
	85
	86	ret = cpuhp_state_remove_instance(lttng_hp_online,
	87	&field->u.perf_counter->cpuhp_online.node);
	88	WARN_ON(ret);
	89	ret = cpuhp_state_remove_instance(lttng_hp_prepare,
	90	&field->u.perf_counter->cpuhp_prepare.node);
	91	WARN_ON(ret);
	92	}
	93	#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
	94	{
	95	int cpu;
	96
	97	get_online_cpus();
	98	for_each_online_cpu(cpu)
	99	perf_event_release_kernel(events[cpu]);
	100	put_online_cpus();
8289661d	101	#ifdef CONFIG_HOTPLUG_CPU
1e367326	102	unregister_cpu_notifier(&field->u.perf_counter->nb);
8289661d	103	#endif
1e367326 MD	104	}
1e367326 MD	105	#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
c24a0d71	106	kfree(field->event_field.name);
2001023e	107	kfree(field->u.perf_counter->attr);
c50bdba2	108	kvfree(events);
2001023e	109	kfree(field->u.perf_counter);
2dccf128 MD	110	}
2dccf128 MD	111
1e367326 MD	112	#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
	113
	114	int lttng_cpuhp_perf_counter_online(unsigned int cpu,
	115	struct lttng_cpuhp_node *node)
	116	{
	117	struct lttng_perf_counter_field *perf_field =
	118	container_of(node, struct lttng_perf_counter_field,
	119	cpuhp_online);
	120	struct perf_event **events = perf_field->e;
	121	struct perf_event_attr *attr = perf_field->attr;
	122	struct perf_event *pevent;
	123
1cacbdc9 MD	124	pevent = perf_event_create_kernel_counter(attr,
1cacbdc9 MD	125	cpu, NULL, overflow_callback, NULL);
1e367326 MD	126	if (!pevent \|\| IS_ERR(pevent))
	127	return -EINVAL;
	128	if (pevent->state == PERF_EVENT_STATE_ERROR) {
	129	perf_event_release_kernel(pevent);
	130	return -EINVAL;
	131	}
	132	barrier(); /* Create perf counter before setting event */
	133	events[cpu] = pevent;
	134	return 0;
	135	}
	136
	137	int lttng_cpuhp_perf_counter_dead(unsigned int cpu,
	138	struct lttng_cpuhp_node *node)
	139	{
	140	struct lttng_perf_counter_field *perf_field =
	141	container_of(node, struct lttng_perf_counter_field,
	142	cpuhp_prepare);
	143	struct perf_event **events = perf_field->e;
	144	struct perf_event *pevent;
	145
	146	pevent = events[cpu];
	147	events[cpu] = NULL;
	148	barrier(); /* NULLify event before perf counter teardown */
	149	perf_event_release_kernel(pevent);
	150	return 0;
	151	}
	152
	153	#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
	154
8289661d MD	155	#ifdef CONFIG_HOTPLUG_CPU
	156
	157	/**
	158	* lttng_perf_counter_hp_callback - CPU hotplug callback
	159	* @nb: notifier block
	160	* @action: hotplug action to take
	161	* @hcpu: CPU number
	162	*
	163	* Returns the success/failure of the operation. (%NOTIFY_OK, %NOTIFY_BAD)
	164	*
	165	* We can setup perf counters when the cpu is online (up prepare seems to be too
	166	* soon).
	167	*/
	168	static
e8f071d5	169	int lttng_perf_counter_cpu_hp_callback(struct notifier_block *nb,
8289661d MD	170	unsigned long action,
	171	void *hcpu)
	172	{
	173	unsigned int cpu = (unsigned long) hcpu;
2001023e MD	174	struct lttng_perf_counter_field *perf_field =
	175	container_of(nb, struct lttng_perf_counter_field, nb);
	176	struct perf_event **events = perf_field->e;
	177	struct perf_event_attr *attr = perf_field->attr;
f91fd73b	178	struct perf_event *pevent;
8289661d	179
2001023e	180	if (!perf_field->hp_enable)
8289661d MD	181	return NOTIFY_OK;
	182
	183	switch (action) {
	184	case CPU_ONLINE:
	185	case CPU_ONLINE_FROZEN:
1cacbdc9 MD	186	pevent = perf_event_create_kernel_counter(attr,
1cacbdc9 MD	187	cpu, NULL, overflow_callback, NULL);
0478c519	188	if (!pevent \|\| IS_ERR(pevent))
8289661d	189	return NOTIFY_BAD;
7b745a96 MD	190	if (pevent->state == PERF_EVENT_STATE_ERROR) {
	191	perf_event_release_kernel(pevent);
	192	return NOTIFY_BAD;
	193	}
f91fd73b MD	194	barrier(); /* Create perf counter before setting event */
f91fd73b MD	195	events[cpu] = pevent;
8289661d MD	196	break;
	197	case CPU_UP_CANCELED:
	198	case CPU_UP_CANCELED_FROZEN:
	199	case CPU_DEAD:
	200	case CPU_DEAD_FROZEN:
f91fd73b MD	201	pevent = events[cpu];
	202	events[cpu] = NULL;
	203	barrier(); /* NULLify event before perf counter teardown */
	204	perf_event_release_kernel(pevent);
8289661d MD	205	break;
	206	}
	207	return NOTIFY_OK;
	208	}
	209
	210	#endif
	211
1e367326 MD	212	#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
1e367326 MD	213
833ad6a0 MD	214	int lttng_add_perf_counter_to_ctx(uint32_t type,
833ad6a0 MD	215	uint64_t config,
c24a0d71	216	const char *name,
2dccf128	217	struct lttng_ctx **ctx)
833ad6a0 MD	218	{
833ad6a0 MD	219	struct lttng_ctx_field *field;
2001023e	220	struct lttng_perf_counter_field *perf_field;
833ad6a0 MD	221	struct perf_event **events;
	222	struct perf_event_attr *attr;
	223	int ret;
c24a0d71	224	char *name_alloc;
833ad6a0	225
c50bdba2	226	events = kvzalloc(num_possible_cpus() * sizeof(*events), GFP_KERNEL);
833ad6a0 MD	227	if (!events)
	228	return -ENOMEM;
	229
2001023e	230	attr = kzalloc(sizeof(struct perf_event_attr), GFP_KERNEL);
833ad6a0 MD	231	if (!attr) {
	232	ret = -ENOMEM;
	233	goto error_attr;
	234	}
	235
	236	attr->type = type;
	237	attr->config = config;
	238	attr->size = sizeof(struct perf_event_attr);
	239	attr->pinned = 1;
	240	attr->disabled = 0;
	241
2001023e MD	242	perf_field = kzalloc(sizeof(struct lttng_perf_counter_field), GFP_KERNEL);
	243	if (!perf_field) {
	244	ret = -ENOMEM;
	245	goto error_alloc_perf_field;
	246	}
	247	perf_field->e = events;
	248	perf_field->attr = attr;
	249
c24a0d71	250	name_alloc = kstrdup(name, GFP_KERNEL);
bef96e48 MD	251	if (!name_alloc) {
bef96e48 MD	252	ret = -ENOMEM;
c24a0d71	253	goto name_alloc_error;
bef96e48	254	}
c24a0d71	255
2dccf128 MD	256	field = lttng_append_context(ctx);
	257	if (!field) {
	258	ret = -ENOMEM;
8289661d	259	goto append_context_error;
833ad6a0	260	}
2001023e	261	if (lttng_find_context(*ctx, name_alloc)) {
44252f0f MD	262	ret = -EEXIST;
	263	goto find_error;
	264	}
8289661d	265
1e367326 MD	266	#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
	267
	268	perf_field->cpuhp_prepare.component = LTTNG_CONTEXT_PERF_COUNTERS;
	269	ret = cpuhp_state_add_instance(lttng_hp_prepare,
	270	&perf_field->cpuhp_prepare.node);
	271	if (ret)
	272	goto cpuhp_prepare_error;
	273
	274	perf_field->cpuhp_online.component = LTTNG_CONTEXT_PERF_COUNTERS;
	275	ret = cpuhp_state_add_instance(lttng_hp_online,
	276	&perf_field->cpuhp_online.node);
	277	if (ret)
	278	goto cpuhp_online_error;
	279
	280	#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
	281	{
	282	int cpu;
	283
8289661d	284	#ifdef CONFIG_HOTPLUG_CPU
1e367326 MD	285	perf_field->nb.notifier_call =
	286	lttng_perf_counter_cpu_hp_callback;
	287	perf_field->nb.priority = 0;
	288	register_cpu_notifier(&perf_field->nb);
8289661d	289	#endif
1e367326 MD	290	get_online_cpus();
1e367326 MD	291	for_each_online_cpu(cpu) {
1cacbdc9 MD	292	events[cpu] = perf_event_create_kernel_counter(attr,
1cacbdc9 MD	293	cpu, NULL, overflow_callback, NULL);
1e367326 MD	294	if (!events[cpu] \|\| IS_ERR(events[cpu])) {
	295	ret = -EINVAL;
	296	goto counter_error;
	297	}
	298	if (events[cpu]->state == PERF_EVENT_STATE_ERROR) {
	299	ret = -EBUSY;
	300	goto counter_busy;
	301	}
7b745a96	302	}
1e367326 MD	303	put_online_cpus();
1e367326 MD	304	perf_field->hp_enable = 1;
8289661d	305	}
1e367326	306	#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
8289661d	307
2dccf128	308	field->destroy = lttng_destroy_perf_counter_field;
833ad6a0	309
c24a0d71	310	field->event_field.name = name_alloc;
8070f5c0	311	field->event_field.type.atype = atype_integer;
ceabb767 MD	312	field->event_field.type.u.integer.size = sizeof(uint64_t) * CHAR_BIT;
	313	field->event_field.type.u.integer.alignment = lttng_alignof(uint64_t) * CHAR_BIT;
	314	field->event_field.type.u.integer.signedness = lttng_is_signed_type(uint64_t);
	315	field->event_field.type.u.integer.reverse_byte_order = 0;
	316	field->event_field.type.u.integer.base = 10;
	317	field->event_field.type.u.integer.encoding = lttng_encode_none;
f1676205 MD	318	field->get_size = perf_counter_get_size;
f1676205 MD	319	field->record = perf_counter_record;
2001023e	320	field->u.perf_counter = perf_field;
a9dd15da	321	lttng_context_update(*ctx);
833ad6a0	322
833ad6a0 MD	323	return 0;
833ad6a0 MD	324
1e367326 MD	325	#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
	326	cpuhp_online_error:
	327	{
	328	int remove_ret;
	329
	330	remove_ret = cpuhp_state_remove_instance(lttng_hp_prepare,
	331	&perf_field->cpuhp_prepare.node);
	332	WARN_ON(remove_ret);
	333	}
	334	cpuhp_prepare_error:
	335	#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
7b745a96	336	counter_busy:
8289661d	337	counter_error:
ce4a2f0c MD	338	{
	339	int cpu;
	340
	341	for_each_online_cpu(cpu) {
	342	if (events[cpu] && !IS_ERR(events[cpu]))
	343	perf_event_release_kernel(events[cpu]);
	344	}
	345	put_online_cpus();
8289661d	346	#ifdef CONFIG_HOTPLUG_CPU
ce4a2f0c	347	unregister_cpu_notifier(&perf_field->nb);
8289661d	348	#endif
ce4a2f0c	349	}
1e367326	350	#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
44252f0f	351	find_error:
8289661d MD	352	lttng_remove_context_field(ctx, field);
	353	append_context_error:
	354	kfree(name_alloc);
	355	name_alloc_error:
2001023e MD	356	kfree(perf_field);
2001023e MD	357	error_alloc_perf_field:
833ad6a0 MD	358	kfree(attr);
833ad6a0 MD	359	error_attr:
c50bdba2	360	kvfree(events);
833ad6a0 MD	361	return ret;
833ad6a0 MD	362	}