Fix: update writeback instrumentation for kernel 4.14
[lttng-modules.git] / lttng-context-nice.c
CommitLineData
53f1f0ca 1/*
886d51a3 2 * lttng-context-nice.c
53f1f0ca
MD
3 *
4 * LTTng nice context.
5 *
886d51a3
MD
6 * Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
7 *
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; only
11 * version 2.1 of the License.
12 *
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with this library; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
53f1f0ca
MD
21 */
22
23#include <linux/module.h>
24#include <linux/slab.h>
25#include <linux/sched.h>
241ae9a8
MD
26#include <lttng-events.h>
27#include <wrapper/ringbuffer/frontend_types.h>
28#include <wrapper/vmalloc.h>
29#include <lttng-tracer.h>
53f1f0ca
MD
30
31static
32size_t nice_get_size(size_t offset)
33{
34 size_t size = 0;
35
a90917c3 36 size += lib_ring_buffer_align(offset, lttng_alignof(int));
53f1f0ca
MD
37 size += sizeof(int);
38 return size;
39}
40
41static
42void nice_record(struct lttng_ctx_field *field,
43 struct lib_ring_buffer_ctx *ctx,
a90917c3 44 struct lttng_channel *chan)
53f1f0ca
MD
45{
46 int nice;
47
48 nice = task_nice(current);
a90917c3 49 lib_ring_buffer_align_ctx(ctx, lttng_alignof(nice));
53f1f0ca
MD
50 chan->ops->event_write(ctx, &nice, sizeof(nice));
51}
52
f127e61e
MD
53static
54void nice_get_value(struct lttng_ctx_field *field,
79150a49 55 struct lttng_probe_ctx *lttng_probe_ctx,
f127e61e
MD
56 union lttng_ctx_value *value)
57{
58 value->s64 = task_nice(current);
59}
60
53f1f0ca
MD
61int lttng_add_nice_to_ctx(struct lttng_ctx **ctx)
62{
63 struct lttng_ctx_field *field;
53f1f0ca
MD
64
65 field = lttng_append_context(ctx);
66 if (!field)
09fec6b4 67 return -ENOMEM;
44252f0f
MD
68 if (lttng_find_context(*ctx, "nice")) {
69 lttng_remove_context_field(ctx, field);
70 return -EEXIST;
71 }
53f1f0ca
MD
72 field->event_field.name = "nice";
73 field->event_field.type.atype = atype_integer;
74 field->event_field.type.u.basic.integer.size = sizeof(int) * CHAR_BIT;
a90917c3 75 field->event_field.type.u.basic.integer.alignment = lttng_alignof(int) * CHAR_BIT;
06254b0f 76 field->event_field.type.u.basic.integer.signedness = lttng_is_signed_type(int);
53f1f0ca
MD
77 field->event_field.type.u.basic.integer.reverse_byte_order = 0;
78 field->event_field.type.u.basic.integer.base = 10;
79 field->event_field.type.u.basic.integer.encoding = lttng_encode_none;
80 field->get_size = nice_get_size;
81 field->record = nice_record;
f127e61e 82 field->get_value = nice_get_value;
a9dd15da 83 lttng_context_update(*ctx);
53f1f0ca
MD
84 wrapper_vmalloc_sync_all();
85 return 0;
86}
87EXPORT_SYMBOL_GPL(lttng_add_nice_to_ctx);
This page took 0.032984 seconds and 4 git commands to generate.