| 1 | /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only) |
| 2 | * |
| 3 | * lttng-counter-client-percpu-64-modular.c |
| 4 | * |
| 5 | * LTTng lib counter client. Per-cpu 64-bit counters in overflow |
| 6 | * arithmetic. |
| 7 | * |
| 8 | * Copyright (C) 2020 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 9 | */ |
| 10 | |
| 11 | #include <linux/module.h> |
| 12 | #include <lttng/tracer.h> |
| 13 | #include <lttng/events.h> |
| 14 | #include <lttng/events-internal.h> |
| 15 | #include <counter/counter.h> |
| 16 | #include <counter/counter-api.h> |
| 17 | |
| 18 | static const struct lib_counter_config client_config = { |
| 19 | .alloc = COUNTER_ALLOC_PER_CPU, |
| 20 | .sync = COUNTER_SYNC_PER_CPU, |
| 21 | .arithmetic = COUNTER_ARITHMETIC_MODULAR, |
| 22 | .counter_size = COUNTER_SIZE_64_BIT, |
| 23 | }; |
| 24 | |
| 25 | static struct lttng_kernel_channel_counter *counter_create(size_t nr_dimensions, |
| 26 | const struct lttng_kernel_counter_dimension *dimensions, |
| 27 | int64_t global_sum_step) |
| 28 | { |
| 29 | size_t max_nr_elem[LTTNG_KERNEL_COUNTER_MAX_DIMENSIONS], i; |
| 30 | struct lttng_kernel_channel_counter *lttng_chan_counter; |
| 31 | struct lib_counter *counter; |
| 32 | |
| 33 | if (nr_dimensions > LTTNG_KERNEL_COUNTER_MAX_DIMENSIONS) |
| 34 | return NULL; |
| 35 | for (i = 0; i < nr_dimensions; i++) { |
| 36 | if ((dimensions[i].flags & LTTNG_KERNEL_COUNTER_DIMENSION_FLAG_UNDERFLOW) |
| 37 | || (dimensions[i].flags & LTTNG_KERNEL_COUNTER_DIMENSION_FLAG_OVERFLOW)) |
| 38 | return NULL; |
| 39 | max_nr_elem[i] = dimensions[i].size; |
| 40 | } |
| 41 | lttng_chan_counter = lttng_kernel_alloc_channel_counter(); |
| 42 | if (!lttng_chan_counter) |
| 43 | return NULL; |
| 44 | counter = lttng_counter_create(&client_config, nr_dimensions, max_nr_elem, |
| 45 | global_sum_step); |
| 46 | if (!counter) |
| 47 | goto error; |
| 48 | lttng_chan_counter->priv->counter = counter; |
| 49 | return lttng_chan_counter; |
| 50 | |
| 51 | error: |
| 52 | lttng_kernel_free_channel_common(<tng_chan_counter->parent); |
| 53 | return NULL; |
| 54 | } |
| 55 | |
| 56 | static void counter_destroy(struct lttng_kernel_channel_counter *counter) |
| 57 | { |
| 58 | lttng_counter_destroy(counter->priv->counter); |
| 59 | lttng_kernel_free_channel_common(&counter->parent); |
| 60 | } |
| 61 | |
| 62 | static int counter_add(struct lttng_kernel_channel_counter *counter, |
| 63 | const size_t *dimension_indexes, int64_t v) |
| 64 | { |
| 65 | return lttng_counter_add(&client_config, counter->priv->counter, dimension_indexes, v); |
| 66 | } |
| 67 | |
| 68 | static int counter_hit(struct lttng_kernel_event_counter *event_counter, |
| 69 | const char *stack_data __attribute__((unused)), |
| 70 | struct lttng_kernel_probe_ctx *probe_ctx __attribute__((unused)), |
| 71 | struct lttng_kernel_event_counter_ctx *event_counter_ctx __attribute__((unused))) |
| 72 | { |
| 73 | struct lttng_kernel_channel_counter *counter = event_counter->chan; |
| 74 | |
| 75 | switch (event_counter->priv->action) { |
| 76 | case LTTNG_EVENT_COUNTER_ACTION_INCREMENT: |
| 77 | { |
| 78 | size_t index = event_counter->priv->parent.id; |
| 79 | return counter_add(counter, &index, 1); |
| 80 | } |
| 81 | default: |
| 82 | return -ENOSYS; |
| 83 | } |
| 84 | } |
| 85 | |
| 86 | static int counter_read(struct lttng_kernel_channel_counter *counter, const size_t *dimension_indexes, int cpu, |
| 87 | int64_t *value, bool *overflow, bool *underflow) |
| 88 | { |
| 89 | return lttng_counter_read(&client_config, counter->priv->counter, dimension_indexes, cpu, value, |
| 90 | overflow, underflow); |
| 91 | } |
| 92 | |
| 93 | static int counter_aggregate(struct lttng_kernel_channel_counter *counter, const size_t *dimension_indexes, |
| 94 | int64_t *value, bool *overflow, bool *underflow) |
| 95 | { |
| 96 | return lttng_counter_aggregate(&client_config, counter->priv->counter, dimension_indexes, value, |
| 97 | overflow, underflow); |
| 98 | } |
| 99 | |
| 100 | static int counter_clear(struct lttng_kernel_channel_counter *counter, const size_t *dimension_indexes) |
| 101 | { |
| 102 | return lttng_counter_clear(&client_config, counter->priv->counter, dimension_indexes); |
| 103 | } |
| 104 | |
| 105 | static int counter_get_nr_dimensions(struct lttng_kernel_channel_counter *counter, size_t *nr_dimensions) |
| 106 | { |
| 107 | return lttng_counter_get_nr_dimensions(&client_config, counter->priv->counter, nr_dimensions); |
| 108 | } |
| 109 | |
| 110 | static int counter_get_max_nr_elem(struct lttng_kernel_channel_counter *counter, size_t *max_nr_elem) |
| 111 | { |
| 112 | return lttng_counter_get_max_nr_elem(&client_config, counter->priv->counter, max_nr_elem); |
| 113 | } |
| 114 | |
| 115 | static struct lttng_counter_transport lttng_counter_transport = { |
| 116 | .name = "counter-per-cpu-64-modular", |
| 117 | .owner = THIS_MODULE, |
| 118 | .ops = { |
| 119 | .priv = __LTTNG_COMPOUND_LITERAL(struct lttng_kernel_channel_counter_ops_private, { |
| 120 | .pub = <tng_counter_transport.ops, |
| 121 | .counter_create = counter_create, |
| 122 | .counter_destroy = counter_destroy, |
| 123 | .counter_add = counter_add, |
| 124 | .counter_read = counter_read, |
| 125 | .counter_aggregate = counter_aggregate, |
| 126 | .counter_clear = counter_clear, |
| 127 | .counter_get_nr_dimensions = counter_get_nr_dimensions, |
| 128 | .counter_get_max_nr_elem = counter_get_max_nr_elem, |
| 129 | }), |
| 130 | .counter_hit = counter_hit, |
| 131 | }, |
| 132 | }; |
| 133 | |
| 134 | static int __init lttng_counter_client_init(void) |
| 135 | { |
| 136 | /* |
| 137 | * This vmalloc sync all also takes care of the lib counter |
| 138 | * vmalloc'd module pages when it is built as a module into LTTng. |
| 139 | */ |
| 140 | wrapper_vmalloc_sync_mappings(); |
| 141 | lttng_counter_transport_register(<tng_counter_transport); |
| 142 | return 0; |
| 143 | } |
| 144 | |
| 145 | module_init(lttng_counter_client_init); |
| 146 | |
| 147 | static void __exit lttng_counter_client_exit(void) |
| 148 | { |
| 149 | lttng_counter_transport_unregister(<tng_counter_transport); |
| 150 | } |
| 151 | |
| 152 | module_exit(lttng_counter_client_exit); |
| 153 | |
| 154 | MODULE_LICENSE("GPL and additional rights"); |
| 155 | MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>"); |
| 156 | MODULE_DESCRIPTION("LTTng counter per-cpu 32-bit overflow client"); |
| 157 | MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "." |
| 158 | __stringify(LTTNG_MODULES_MINOR_VERSION) "." |
| 159 | __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION) |
| 160 | LTTNG_MODULES_EXTRAVERSION); |