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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) |
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, |
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) { |
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; |
187 | field->record = perf_counter_record; | |
833ad6a0 MD |
188 | field->u.perf_counter.e = events; |
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"); |