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

/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
 *
 * 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 <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;
}
Commit	Line	Data
9f36eaed MJ	1	/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
9f36eaed MJ	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>
241ae9a8 MD	16	#include <lttng-events.h>
	17	#include <wrapper/ringbuffer/frontend_types.h>
	18	#include <wrapper/vmalloc.h>
	19	#include <wrapper/perf.h>
	20	#include <lttng-tracer.h>
833ad6a0	21
f1676205 MD	22	static
	23	size_t perf_counter_get_size(size_t offset)
	24	{
	25	size_t size = 0;
	26
a90917c3	27	size += lib_ring_buffer_align(offset, lttng_alignof(uint64_t));
f1676205 MD	28	size += sizeof(uint64_t);
	29	return size;
	30	}
	31
833ad6a0 MD	32	static
	33	void perf_counter_record(struct lttng_ctx_field *field,
	34	struct lib_ring_buffer_ctx *ctx,
a90917c3	35	struct lttng_channel *chan)
833ad6a0 MD	36	{
	37	struct perf_event *event;
	38	uint64_t value;
	39
2001023e	40	event = field->u.perf_counter->e[ctx->cpu];
0478c519	41	if (likely(event)) {
7b745a96 MD	42	if (unlikely(event->state == PERF_EVENT_STATE_ERROR)) {
	43	value = 0;
	44	} else {
	45	event->pmu->read(event);
	46	value = local64_read(&event->count);
	47	}
f91fd73b MD	48	} else {
	49	/*
	50	* Perf chooses not to be clever and not to support enabling a
	51	* perf counter before the cpu is brought up. Therefore, we need
	52	* to support having events coming (e.g. scheduler events)
	53	* before the counter is setup. Write an arbitrary 0 in this
	54	* case.
	55	*/
	56	value = 0;
	57	}
a90917c3	58	lib_ring_buffer_align_ctx(ctx, lttng_alignof(value));
833ad6a0 MD	59	chan->ops->event_write(ctx, &value, sizeof(value));
	60	}
	61
90f5546c MD	62	#if defined(CONFIG_PERF_EVENTS) && (LINUX_VERSION_CODE >= KERNEL_VERSION(3,0,99))
	63	static
	64	void overflow_callback(struct perf_event *event,
	65	struct perf_sample_data *data,
	66	struct pt_regs *regs)
	67	{
	68	}
	69	#else
833ad6a0 MD	70	static
	71	void overflow_callback(struct perf_event *event, int nmi,
	72	struct perf_sample_data *data,
	73	struct pt_regs *regs)
	74	{
	75	}
90f5546c	76	#endif
833ad6a0	77
2dccf128 MD	78	static
	79	void lttng_destroy_perf_counter_field(struct lttng_ctx_field *field)
	80	{
2001023e	81	struct perf_event **events = field->u.perf_counter->e;
2dccf128	82
1e367326 MD	83	#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
	84	{
	85	int ret;
	86
	87	ret = cpuhp_state_remove_instance(lttng_hp_online,
	88	&field->u.perf_counter->cpuhp_online.node);
	89	WARN_ON(ret);
	90	ret = cpuhp_state_remove_instance(lttng_hp_prepare,
	91	&field->u.perf_counter->cpuhp_prepare.node);
	92	WARN_ON(ret);
	93	}
	94	#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
	95	{
	96	int cpu;
	97
	98	get_online_cpus();
	99	for_each_online_cpu(cpu)
	100	perf_event_release_kernel(events[cpu]);
	101	put_online_cpus();
8289661d	102	#ifdef CONFIG_HOTPLUG_CPU
1e367326	103	unregister_cpu_notifier(&field->u.perf_counter->nb);
8289661d	104	#endif
1e367326 MD	105	}
1e367326 MD	106	#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
c24a0d71	107	kfree(field->event_field.name);
2001023e	108	kfree(field->u.perf_counter->attr);
48f5e0b5	109	lttng_kvfree(events);
2001023e	110	kfree(field->u.perf_counter);
2dccf128 MD	111	}
2dccf128 MD	112
1e367326 MD	113	#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
	114
	115	int lttng_cpuhp_perf_counter_online(unsigned int cpu,
	116	struct lttng_cpuhp_node *node)
	117	{
	118	struct lttng_perf_counter_field *perf_field =
	119	container_of(node, struct lttng_perf_counter_field,
	120	cpuhp_online);
	121	struct perf_event **events = perf_field->e;
	122	struct perf_event_attr *attr = perf_field->attr;
	123	struct perf_event *pevent;
	124
	125	pevent = wrapper_perf_event_create_kernel_counter(attr,
	126	cpu, NULL, overflow_callback);
	127	if (!pevent \|\| IS_ERR(pevent))
	128	return -EINVAL;
	129	if (pevent->state == PERF_EVENT_STATE_ERROR) {
	130	perf_event_release_kernel(pevent);
	131	return -EINVAL;
	132	}
	133	barrier(); /* Create perf counter before setting event */
	134	events[cpu] = pevent;
	135	return 0;
	136	}
	137
	138	int lttng_cpuhp_perf_counter_dead(unsigned int cpu,
	139	struct lttng_cpuhp_node *node)
	140	{
	141	struct lttng_perf_counter_field *perf_field =
	142	container_of(node, struct lttng_perf_counter_field,
	143	cpuhp_prepare);
	144	struct perf_event **events = perf_field->e;
	145	struct perf_event *pevent;
	146
	147	pevent = events[cpu];
	148	events[cpu] = NULL;
	149	barrier(); /* NULLify event before perf counter teardown */
	150	perf_event_release_kernel(pevent);
	151	return 0;
	152	}
	153
	154	#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
	155
8289661d MD	156	#ifdef CONFIG_HOTPLUG_CPU
	157
	158	/**
	159	* lttng_perf_counter_hp_callback - CPU hotplug callback
	160	* @nb: notifier block
	161	* @action: hotplug action to take
	162	* @hcpu: CPU number
	163	*
	164	* Returns the success/failure of the operation. (%NOTIFY_OK, %NOTIFY_BAD)
	165	*
	166	* We can setup perf counters when the cpu is online (up prepare seems to be too
	167	* soon).
	168	*/
	169	static
e8f071d5	170	int lttng_perf_counter_cpu_hp_callback(struct notifier_block *nb,
8289661d MD	171	unsigned long action,
	172	void *hcpu)
	173	{
	174	unsigned int cpu = (unsigned long) hcpu;
2001023e MD	175	struct lttng_perf_counter_field *perf_field =
	176	container_of(nb, struct lttng_perf_counter_field, nb);
	177	struct perf_event **events = perf_field->e;
	178	struct perf_event_attr *attr = perf_field->attr;
f91fd73b	179	struct perf_event *pevent;
8289661d	180
2001023e	181	if (!perf_field->hp_enable)
8289661d MD	182	return NOTIFY_OK;
	183
	184	switch (action) {
	185	case CPU_ONLINE:
	186	case CPU_ONLINE_FROZEN:
90f5546c	187	pevent = wrapper_perf_event_create_kernel_counter(attr,
8289661d	188	cpu, NULL, overflow_callback);
0478c519	189	if (!pevent \|\| IS_ERR(pevent))
8289661d	190	return NOTIFY_BAD;
7b745a96 MD	191	if (pevent->state == PERF_EVENT_STATE_ERROR) {
	192	perf_event_release_kernel(pevent);
	193	return NOTIFY_BAD;
	194	}
f91fd73b MD	195	barrier(); /* Create perf counter before setting event */
f91fd73b MD	196	events[cpu] = pevent;
8289661d MD	197	break;
	198	case CPU_UP_CANCELED:
	199	case CPU_UP_CANCELED_FROZEN:
	200	case CPU_DEAD:
	201	case CPU_DEAD_FROZEN:
f91fd73b MD	202	pevent = events[cpu];
	203	events[cpu] = NULL;
	204	barrier(); /* NULLify event before perf counter teardown */
	205	perf_event_release_kernel(pevent);
8289661d MD	206	break;
	207	}
	208	return NOTIFY_OK;
	209	}
	210
	211	#endif
	212
1e367326 MD	213	#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
1e367326 MD	214
833ad6a0 MD	215	int lttng_add_perf_counter_to_ctx(uint32_t type,
833ad6a0 MD	216	uint64_t config,
c24a0d71	217	const char *name,
2dccf128	218	struct lttng_ctx **ctx)
833ad6a0 MD	219	{
833ad6a0 MD	220	struct lttng_ctx_field *field;
2001023e	221	struct lttng_perf_counter_field *perf_field;
833ad6a0 MD	222	struct perf_event **events;
	223	struct perf_event_attr *attr;
	224	int ret;
c24a0d71	225	char *name_alloc;
833ad6a0	226
48f5e0b5	227	events = lttng_kvzalloc(num_possible_cpus() * sizeof(*events), GFP_KERNEL);
833ad6a0 MD	228	if (!events)
	229	return -ENOMEM;
	230
2001023e	231	attr = kzalloc(sizeof(struct perf_event_attr), GFP_KERNEL);
833ad6a0 MD	232	if (!attr) {
	233	ret = -ENOMEM;
	234	goto error_attr;
	235	}
	236
	237	attr->type = type;
	238	attr->config = config;
	239	attr->size = sizeof(struct perf_event_attr);
	240	attr->pinned = 1;
	241	attr->disabled = 0;
	242
2001023e MD	243	perf_field = kzalloc(sizeof(struct lttng_perf_counter_field), GFP_KERNEL);
	244	if (!perf_field) {
	245	ret = -ENOMEM;
	246	goto error_alloc_perf_field;
	247	}
	248	perf_field->e = events;
	249	perf_field->attr = attr;
	250
c24a0d71	251	name_alloc = kstrdup(name, GFP_KERNEL);
bef96e48 MD	252	if (!name_alloc) {
bef96e48 MD	253	ret = -ENOMEM;
c24a0d71	254	goto name_alloc_error;
bef96e48	255	}
c24a0d71	256
2dccf128 MD	257	field = lttng_append_context(ctx);
	258	if (!field) {
	259	ret = -ENOMEM;
8289661d	260	goto append_context_error;
833ad6a0	261	}
2001023e	262	if (lttng_find_context(*ctx, name_alloc)) {
44252f0f MD	263	ret = -EEXIST;
	264	goto find_error;
	265	}
8289661d	266
1e367326 MD	267	#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
	268
	269	perf_field->cpuhp_prepare.component = LTTNG_CONTEXT_PERF_COUNTERS;
	270	ret = cpuhp_state_add_instance(lttng_hp_prepare,
	271	&perf_field->cpuhp_prepare.node);
	272	if (ret)
	273	goto cpuhp_prepare_error;
	274
	275	perf_field->cpuhp_online.component = LTTNG_CONTEXT_PERF_COUNTERS;
	276	ret = cpuhp_state_add_instance(lttng_hp_online,
	277	&perf_field->cpuhp_online.node);
	278	if (ret)
	279	goto cpuhp_online_error;
	280
	281	#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
	282	{
	283	int cpu;
	284
8289661d	285	#ifdef CONFIG_HOTPLUG_CPU
1e367326 MD	286	perf_field->nb.notifier_call =
	287	lttng_perf_counter_cpu_hp_callback;
	288	perf_field->nb.priority = 0;
	289	register_cpu_notifier(&perf_field->nb);
8289661d	290	#endif
1e367326 MD	291	get_online_cpus();
	292	for_each_online_cpu(cpu) {
	293	events[cpu] = wrapper_perf_event_create_kernel_counter(attr,
	294	cpu, NULL, overflow_callback);
	295	if (!events[cpu] \|\| IS_ERR(events[cpu])) {
	296	ret = -EINVAL;
	297	goto counter_error;
	298	}
	299	if (events[cpu]->state == PERF_EVENT_STATE_ERROR) {
	300	ret = -EBUSY;
	301	goto counter_busy;
	302	}
7b745a96	303	}
1e367326 MD	304	put_online_cpus();
1e367326 MD	305	perf_field->hp_enable = 1;
8289661d	306	}
1e367326	307	#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
8289661d	308
2dccf128	309	field->destroy = lttng_destroy_perf_counter_field;
833ad6a0	310
c24a0d71	311	field->event_field.name = name_alloc;
8070f5c0	312	field->event_field.type.atype = atype_integer;
9d7d747f	313	field->event_field.type.u.basic.integer.size = sizeof(uint64_t) * CHAR_BIT;
a90917c3	314	field->event_field.type.u.basic.integer.alignment = lttng_alignof(uint64_t) * CHAR_BIT;
06254b0f	315	field->event_field.type.u.basic.integer.signedness = lttng_is_signed_type(uint64_t);
8070f5c0 MD	316	field->event_field.type.u.basic.integer.reverse_byte_order = 0;
	317	field->event_field.type.u.basic.integer.base = 10;
	318	field->event_field.type.u.basic.integer.encoding = lttng_encode_none;
f1676205 MD	319	field->get_size = perf_counter_get_size;
f1676205 MD	320	field->record = perf_counter_record;
2001023e	321	field->u.perf_counter = perf_field;
a9dd15da	322	lttng_context_update(*ctx);
833ad6a0 MD	323
	324	wrapper_vmalloc_sync_all();
	325	return 0;
	326
1e367326 MD	327	#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0))
	328	cpuhp_online_error:
	329	{
	330	int remove_ret;
	331
	332	remove_ret = cpuhp_state_remove_instance(lttng_hp_prepare,
	333	&perf_field->cpuhp_prepare.node);
	334	WARN_ON(remove_ret);
	335	}
	336	cpuhp_prepare_error:
	337	#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
7b745a96	338	counter_busy:
8289661d	339	counter_error:
ce4a2f0c MD	340	{
	341	int cpu;
	342
	343	for_each_online_cpu(cpu) {
	344	if (events[cpu] && !IS_ERR(events[cpu]))
	345	perf_event_release_kernel(events[cpu]);
	346	}
	347	put_online_cpus();
8289661d	348	#ifdef CONFIG_HOTPLUG_CPU
ce4a2f0c	349	unregister_cpu_notifier(&perf_field->nb);
8289661d	350	#endif
ce4a2f0c	351	}
1e367326	352	#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */
44252f0f	353	find_error:
8289661d MD	354	lttng_remove_context_field(ctx, field);
	355	append_context_error:
	356	kfree(name_alloc);
	357	name_alloc_error:
2001023e MD	358	kfree(perf_field);
2001023e MD	359	error_alloc_perf_field:
833ad6a0 MD	360	kfree(attr);
833ad6a0 MD	361	error_attr:
48f5e0b5	362	lttng_kvfree(events);
833ad6a0 MD	363	return ret;
833ad6a0 MD	364	}