projects / lttng-ust.git / blame
| Commit | Line | Data |
|---|---|---|
| c7ea8487 MD |
1 | /* |
| 2 | * lttng-context-cpu-id.c | |
| 3 | * | |
| 4 | * LTTng UST CPU id context. | |
| 5 | * | |
| 6 | * Note: threads can be migrated at any point while executing the | |
| 7 | * tracepoint probe. This means the CPU id field (and filter) is only | |
| 8 | * statistical. For instance, even though a user might select a | |
| 9 | * cpu_id==1 filter, there may be few events recorded into the channel | |
| 10 | * appearing from other CPUs, due to migration. | |
| 11 | * | |
| 12 | * Copyright (C) 2009-2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
| 13 | * | |
| 14 | * This library is free software; you can redistribute it and/or | |
| 15 | * modify it under the terms of the GNU Lesser General Public | |
| 16 | * License as published by the Free Software Foundation; only | |
| 17 | * version 2.1 of the License. | |
| 18 | * | |
| 19 | * This library is distributed in the hope that it will be useful, | |
| 20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 22 | * Lesser General Public License for more details. | |
| 23 | * | |
| 24 | * You should have received a copy of the GNU Lesser General Public | |
| 25 | * License along with this library; if not, write to the Free Software | |
| 26 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
| 27 | */ | |
| 28 | ||
| 29 | #define _GNU_SOURCE | |
| 30 | #include <sys/types.h> | |
| 31 | #include <unistd.h> | |
| 32 | #include <lttng/ust-events.h> | |
| 33 | #include <lttng/ust-tracer.h> | |
| 34 | #include <lttng/ringbuffer-config.h> | |
| 35 | #include "../libringbuffer/getcpu.h" | |
| 36 | ||
| 37 | static | |
| 53569322 | 38 | size_t cpu_id_get_size(struct lttng_ctx_field *field, size_t offset) |
| c7ea8487 MD |
39 | { |
| 40 | size_t size = 0; | |
| 41 | ||
| 42 | size += lib_ring_buffer_align(offset, lttng_alignof(int)); | |
| 43 | size += sizeof(int); | |
| 44 | return size; | |
| 45 | } | |
| 46 | ||
| 47 | static | |
| 48 | void cpu_id_record(struct lttng_ctx_field *field, | |
| 49 | struct lttng_ust_lib_ring_buffer_ctx *ctx, | |
| 50 | struct lttng_channel *chan) | |
| 51 | { | |
| 52 | int cpu; | |
| 53 | ||
| 54 | cpu = lttng_ust_get_cpu(); | |
| 55 | lib_ring_buffer_align_ctx(ctx, lttng_alignof(cpu)); | |
| 56 | chan->ops->event_write(ctx, &cpu, sizeof(cpu)); | |
| 57 | } | |
| 58 | ||
| 59 | static | |
| 60 | void cpu_id_get_value(struct lttng_ctx_field *field, | |
| 53569322 | 61 | struct lttng_ctx_value *value) |
| c7ea8487 MD |
62 | { |
| 63 | int cpu; | |
| 64 | ||
| 65 | cpu = lttng_ust_get_cpu(); | |
| 53569322 | 66 | value->u.s64 = cpu; |
| c7ea8487 MD |
67 | } |
| 68 | ||
| 69 | int lttng_add_cpu_id_to_ctx(struct lttng_ctx **ctx) | |
| 70 | { | |
| 71 | struct lttng_ctx_field *field; | |
| 72 | ||
| 73 | field = lttng_append_context(ctx); | |
| 74 | if (!field) | |
| 75 | return -ENOMEM; | |
| 76 | if (lttng_find_context(*ctx, "cpu_id")) { | |
| 77 | lttng_remove_context_field(ctx, field); | |
| 78 | return -EEXIST; | |
| 79 | } | |
| 80 | field->event_field.name = "cpu_id"; | |
| 81 | field->event_field.type.atype = atype_integer; | |
| 82 | field->event_field.type.u.basic.integer.size = sizeof(int) * CHAR_BIT; | |
| 83 | field->event_field.type.u.basic.integer.alignment = lttng_alignof(int) * CHAR_BIT; | |
| 84 | field->event_field.type.u.basic.integer.signedness = lttng_is_signed_type(int); | |
| 85 | field->event_field.type.u.basic.integer.reverse_byte_order = 0; | |
| 86 | field->event_field.type.u.basic.integer.base = 10; | |
| 87 | field->event_field.type.u.basic.integer.encoding = lttng_encode_none; | |
| 88 | field->get_size = cpu_id_get_size; | |
| 89 | field->record = cpu_id_record; | |
| 90 | field->get_value = cpu_id_get_value; | |
| 91 | lttng_context_update(*ctx); | |
| 92 | return 0; | |
| 93 | } |