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 | |
3fbec7dc | 30 | #define _LGPL_SOURCE |
b4051ad8 | 31 | #include <stddef.h> |
c7ea8487 MD |
32 | #include <sys/types.h> |
33 | #include <unistd.h> | |
34 | #include <lttng/ust-events.h> | |
35 | #include <lttng/ust-tracer.h> | |
36 | #include <lttng/ringbuffer-config.h> | |
37 | #include "../libringbuffer/getcpu.h" | |
38 | ||
39 | static | |
53569322 | 40 | size_t cpu_id_get_size(struct lttng_ctx_field *field, size_t offset) |
c7ea8487 MD |
41 | { |
42 | size_t size = 0; | |
43 | ||
44 | size += lib_ring_buffer_align(offset, lttng_alignof(int)); | |
45 | size += sizeof(int); | |
46 | return size; | |
47 | } | |
48 | ||
49 | static | |
50 | void cpu_id_record(struct lttng_ctx_field *field, | |
51 | struct lttng_ust_lib_ring_buffer_ctx *ctx, | |
52 | struct lttng_channel *chan) | |
53 | { | |
54 | int cpu; | |
55 | ||
56 | cpu = lttng_ust_get_cpu(); | |
57 | lib_ring_buffer_align_ctx(ctx, lttng_alignof(cpu)); | |
58 | chan->ops->event_write(ctx, &cpu, sizeof(cpu)); | |
59 | } | |
60 | ||
61 | static | |
62 | void cpu_id_get_value(struct lttng_ctx_field *field, | |
53569322 | 63 | struct lttng_ctx_value *value) |
c7ea8487 | 64 | { |
6e9ac4ae | 65 | value->u.s64 = lttng_ust_get_cpu(); |
c7ea8487 MD |
66 | } |
67 | ||
68 | int lttng_add_cpu_id_to_ctx(struct lttng_ctx **ctx) | |
69 | { | |
70 | struct lttng_ctx_field *field; | |
71 | ||
72 | field = lttng_append_context(ctx); | |
73 | if (!field) | |
74 | return -ENOMEM; | |
75 | if (lttng_find_context(*ctx, "cpu_id")) { | |
76 | lttng_remove_context_field(ctx, field); | |
77 | return -EEXIST; | |
78 | } | |
79 | field->event_field.name = "cpu_id"; | |
80 | field->event_field.type.atype = atype_integer; | |
81 | field->event_field.type.u.basic.integer.size = sizeof(int) * CHAR_BIT; | |
82 | field->event_field.type.u.basic.integer.alignment = lttng_alignof(int) * CHAR_BIT; | |
83 | field->event_field.type.u.basic.integer.signedness = lttng_is_signed_type(int); | |
84 | field->event_field.type.u.basic.integer.reverse_byte_order = 0; | |
85 | field->event_field.type.u.basic.integer.base = 10; | |
86 | field->event_field.type.u.basic.integer.encoding = lttng_encode_none; | |
87 | field->get_size = cpu_id_get_size; | |
88 | field->record = cpu_id_record; | |
89 | field->get_value = cpu_id_get_value; | |
90 | lttng_context_update(*ctx); | |
91 | return 0; | |
92 | } |