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

/*
 * (C) Copyright	2009-2011 -
 * 		Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * LTTng performance monitoring counters (perf-counters) integration module.
 *
 * Dual LGPL v2.1/GPL v2 license.
 */

#include <linux/module.h>
#include <linux/slab.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"

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 += 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 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));
	chan->ops->event_write(ctx, &value, sizeof(value));
}

static
void overflow_callback(struct perf_event *event, int nmi,
		       struct perf_sample_data *data,
		       struct pt_regs *regs)
{
}

static
void lttng_destroy_perf_counter_field(struct lttng_ctx_field *field)
{
	struct perf_event **events = field->u.perf_counter.e;
	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
	kfree(field->event_field.name);
	kfree(field->u.perf_counter.attr);
	kfree(events);
}

#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 __cpuinit lttng_perf_counter_cpu_hp_callback(struct notifier_block *nb,
						 unsigned long action,
						 void *hcpu)
{
	unsigned int cpu = (unsigned long) hcpu;
	struct lttng_ctx_field *field =
		container_of(nb, struct lttng_ctx_field, u.perf_counter.nb);
	struct perf_event **events = field->u.perf_counter.e;
	struct perf_event_attr *attr = field->u.perf_counter.attr;
	

	if (!field->u.perf_counter.hp_enable)
		return NOTIFY_OK;

	switch (action) {
	case CPU_ONLINE:
	case CPU_ONLINE_FROZEN:
		events[cpu] = perf_event_create_kernel_counter(attr,
				cpu, NULL, overflow_callback);
		if (!events[cpu])
			return NOTIFY_BAD;
		break;
	case CPU_UP_CANCELED:
	case CPU_UP_CANCELED_FROZEN:
	case CPU_DEAD:
	case CPU_DEAD_FROZEN:
		perf_event_release_kernel(events[cpu]);
		break;
	}
	return NOTIFY_OK;
}

#endif

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 perf_event **events;
	struct perf_event_attr *attr;
	int ret;
	int cpu;
	char *name_alloc;

	events = kzalloc(num_possible_cpus() * sizeof(*events), GFP_KERNEL);
	if (!events)
		return -ENOMEM;

	attr = kzalloc(sizeof(*field->u.perf_counter.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;

	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;
	}

#ifdef CONFIG_HOTPLUG_CPU
	field->u.perf_counter.nb.notifier_call =
		lttng_perf_counter_cpu_hp_callback;
	field->u.perf_counter.nb.priority = 0;
	register_cpu_notifier(&field->u.perf_counter.nb);
#endif

	get_online_cpus();
	for_each_online_cpu(cpu) {
		events[cpu] = perf_event_create_kernel_counter(attr,
					cpu, NULL, overflow_callback);
		if (!events[cpu]) {
			ret = -EINVAL;
			goto counter_error;
		}
	}
	put_online_cpus();

	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.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;
	field->u.perf_counter.hp_enable = 1;

	wrapper_vmalloc_sync_all();
	return 0;

counter_error:
	for_each_online_cpu(cpu) {
		if (events[cpu])
			perf_event_release_kernel(events[cpu]);
	}
	put_online_cpus();
#ifdef CONFIG_HOTPLUG_CPU
	unregister_cpu_notifier(&field->u.perf_counter.nb);
#endif
	lttng_remove_context_field(ctx, field);
append_context_error:
	kfree(name_alloc);
name_alloc_error:
	kfree(attr);
error_attr:
	kfree(events);
	return ret;
}

MODULE_LICENSE("GPL and additional rights");
MODULE_AUTHOR("Mathieu Desnoyers");
MODULE_DESCRIPTION("Linux Trace Toolkit Perf Support");
Commit	Line	Data
833ad6a0 MD	1	/*
	2	* (C) Copyright 2009-2011 -
	3	* Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	4	*
	5	* LTTng performance monitoring counters (perf-counters) integration module.
	6	*
	7	* Dual LGPL v2.1/GPL v2 license.
	8	*/
	9
	10	#include <linux/module.h>
	11	#include <linux/slab.h>
	12	#include <linux/perf_event.h>
	13	#include <linux/list.h>
c24a0d71 MD	14	#include <linux/string.h>
	15	#include "ltt-events.h"
	16	#include "wrapper/ringbuffer/frontend_types.h"
	17	#include "wrapper/vmalloc.h"
	18	#include "ltt-tracer.h"
833ad6a0	19
f1676205 MD	20	static
	21	size_t perf_counter_get_size(size_t offset)
	22	{
	23	size_t size = 0;
	24
	25	size += lib_ring_buffer_align(offset, ltt_alignof(uint64_t));
	26	size += sizeof(uint64_t);
	27	return size;
	28	}
	29
833ad6a0 MD	30	static
	31	void perf_counter_record(struct lttng_ctx_field *field,
	32	struct lib_ring_buffer_ctx *ctx,
	33	struct ltt_channel *chan)
	34	{
	35	struct perf_event *event;
	36	uint64_t value;
	37
	38	event = field->u.perf_counter.e[ctx->cpu];
	39	event->pmu->read(event);
	40	value = local64_read(&event->count);
9e7e4892	41	lib_ring_buffer_align_ctx(ctx, ltt_alignof(value));
833ad6a0 MD	42	chan->ops->event_write(ctx, &value, sizeof(value));
	43	}
	44
	45	static
	46	void overflow_callback(struct perf_event *event, int nmi,
	47	struct perf_sample_data *data,
	48	struct pt_regs *regs)
	49	{
	50	}
	51
2dccf128 MD	52	static
	53	void lttng_destroy_perf_counter_field(struct lttng_ctx_field *field)
	54	{
	55	struct perf_event **events = field->u.perf_counter.e;
	56	int cpu;
	57
8289661d	58	get_online_cpus();
2dccf128 MD	59	for_each_online_cpu(cpu)
2dccf128 MD	60	perf_event_release_kernel(events[cpu]);
8289661d MD	61	put_online_cpus();
	62	#ifdef CONFIG_HOTPLUG_CPU
	63	unregister_cpu_notifier(&field->u.perf_counter.nb);
	64	#endif
c24a0d71	65	kfree(field->event_field.name);
2dccf128 MD	66	kfree(field->u.perf_counter.attr);
	67	kfree(events);
	68	}
	69
8289661d MD	70	#ifdef CONFIG_HOTPLUG_CPU
	71
	72	/**
	73	* lttng_perf_counter_hp_callback - CPU hotplug callback
	74	* @nb: notifier block
	75	* @action: hotplug action to take
	76	* @hcpu: CPU number
	77	*
	78	* Returns the success/failure of the operation. (%NOTIFY_OK, %NOTIFY_BAD)
	79	*
	80	* We can setup perf counters when the cpu is online (up prepare seems to be too
	81	* soon).
	82	*/
	83	static
	84	int __cpuinit lttng_perf_counter_cpu_hp_callback(struct notifier_block *nb,
	85	unsigned long action,
	86	void *hcpu)
	87	{
	88	unsigned int cpu = (unsigned long) hcpu;
	89	struct lttng_ctx_field *field =
	90	container_of(nb, struct lttng_ctx_field, u.perf_counter.nb);
	91	struct perf_event **events = field->u.perf_counter.e;
	92	struct perf_event_attr *attr = field->u.perf_counter.attr;
	93
	94
	95	if (!field->u.perf_counter.hp_enable)
	96	return NOTIFY_OK;
	97
	98	switch (action) {
	99	case CPU_ONLINE:
	100	case CPU_ONLINE_FROZEN:
	101	events[cpu] = perf_event_create_kernel_counter(attr,
	102	cpu, NULL, overflow_callback);
	103	if (!events[cpu])
	104	return NOTIFY_BAD;
	105	break;
	106	case CPU_UP_CANCELED:
	107	case CPU_UP_CANCELED_FROZEN:
	108	case CPU_DEAD:
	109	case CPU_DEAD_FROZEN:
	110	perf_event_release_kernel(events[cpu]);
	111	break;
	112	}
	113	return NOTIFY_OK;
	114	}
	115
	116	#endif
	117
833ad6a0 MD	118	int lttng_add_perf_counter_to_ctx(uint32_t type,
833ad6a0 MD	119	uint64_t config,
c24a0d71	120	const char *name,
2dccf128	121	struct lttng_ctx **ctx)
833ad6a0 MD	122	{
	123	struct lttng_ctx_field *field;
	124	struct perf_event **events;
	125	struct perf_event_attr *attr;
	126	int ret;
	127	int cpu;
c24a0d71	128	char *name_alloc;
833ad6a0 MD	129
	130	events = kzalloc(num_possible_cpus() * sizeof(*events), GFP_KERNEL);
	131	if (!events)
	132	return -ENOMEM;
	133
	134	attr = kzalloc(sizeof(*field->u.perf_counter.attr), GFP_KERNEL);
	135	if (!attr) {
	136	ret = -ENOMEM;
	137	goto error_attr;
	138	}
	139
	140	attr->type = type;
	141	attr->config = config;
	142	attr->size = sizeof(struct perf_event_attr);
	143	attr->pinned = 1;
	144	attr->disabled = 0;
	145
c24a0d71	146	name_alloc = kstrdup(name, GFP_KERNEL);
bef96e48 MD	147	if (!name_alloc) {
bef96e48 MD	148	ret = -ENOMEM;
c24a0d71	149	goto name_alloc_error;
bef96e48	150	}
c24a0d71	151
2dccf128 MD	152	field = lttng_append_context(ctx);
	153	if (!field) {
	154	ret = -ENOMEM;
8289661d	155	goto append_context_error;
833ad6a0	156	}
8289661d MD	157
	158	#ifdef CONFIG_HOTPLUG_CPU
	159	field->u.perf_counter.nb.notifier_call =
	160	lttng_perf_counter_cpu_hp_callback;
	161	field->u.perf_counter.nb.priority = 0;
	162	register_cpu_notifier(&field->u.perf_counter.nb);
	163	#endif
	164
	165	get_online_cpus();
	166	for_each_online_cpu(cpu) {
	167	events[cpu] = perf_event_create_kernel_counter(attr,
	168	cpu, NULL, overflow_callback);
	169	if (!events[cpu]) {
	170	ret = -EINVAL;
	171	goto counter_error;
	172	}
	173	}
	174	put_online_cpus();
	175
2dccf128	176	field->destroy = lttng_destroy_perf_counter_field;
833ad6a0	177
c24a0d71	178	field->event_field.name = name_alloc;
8070f5c0 MD	179	field->event_field.type.atype = atype_integer;
	180	field->event_field.type.u.basic.integer.size = sizeof(unsigned long) * CHAR_BIT;
	181	field->event_field.type.u.basic.integer.alignment = ltt_alignof(unsigned long) * CHAR_BIT;
	182	field->event_field.type.u.basic.integer.signedness = is_signed_type(unsigned long);
	183	field->event_field.type.u.basic.integer.reverse_byte_order = 0;
	184	field->event_field.type.u.basic.integer.base = 10;
	185	field->event_field.type.u.basic.integer.encoding = lttng_encode_none;
f1676205 MD	186	field->get_size = perf_counter_get_size;
f1676205 MD	187	field->record = perf_counter_record;
833ad6a0 MD	188	field->u.perf_counter.e = events;
833ad6a0 MD	189	field->u.perf_counter.attr = attr;
8289661d	190	field->u.perf_counter.hp_enable = 1;
833ad6a0 MD	191
	192	wrapper_vmalloc_sync_all();
	193	return 0;
	194
8289661d	195	counter_error:
833ad6a0 MD	196	for_each_online_cpu(cpu) {
	197	if (events[cpu])
	198	perf_event_release_kernel(events[cpu]);
	199	}
8289661d MD	200	put_online_cpus();
	201	#ifdef CONFIG_HOTPLUG_CPU
	202	unregister_cpu_notifier(&field->u.perf_counter.nb);
	203	#endif
	204	lttng_remove_context_field(ctx, field);
	205	append_context_error:
	206	kfree(name_alloc);
	207	name_alloc_error:
833ad6a0 MD	208	kfree(attr);
	209	error_attr:
	210	kfree(events);
	211	return ret;
	212	}
	213
833ad6a0 MD	214	MODULE_LICENSE("GPL and additional rights");
	215	MODULE_AUTHOR("Mathieu Desnoyers");
	216	MODULE_DESCRIPTION("Linux Trace Toolkit Perf Support");