projects / lttng-modules.git / blame
| Commit | Line | Data |
|---|---|---|
| a8ad3613 MD |
1 | /* |
| 2 | * (C) Copyright 2009-2011 - | |
| 3 | * Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
| 4 | * | |
| 5 | * LTTng priority context. | |
| 6 | * | |
| 7 | * Dual LGPL v2.1/GPL v2 license. | |
| 8 | */ | |
| 9 | ||
| 10 | #include <linux/module.h> | |
| 11 | #include <linux/slab.h> | |
| 12 | #include <linux/sched.h> | |
| 13 | #include "ltt-events.h" | |
| 14 | #include "wrapper/ringbuffer/frontend_types.h" | |
| 15 | #include "wrapper/vmalloc.h" | |
| 16 | #include "ltt-tracer.h" | |
| 17 | ||
| 979133c5 MD |
18 | static |
| 19 | int (*wrapper_task_prio_sym)(struct task_struct *t); | |
| 20 | ||
| 21 | int wrapper_task_prio_init(void) | |
| 22 | { | |
| 23 | wrapper_task_prio_sym = (void *) kallsyms_lookup_name("task_prio"); | |
| 24 | if (!wrapper_task_prio_sym) { | |
| 25 | printk(KERN_WARNING "LTTng: task_prio symbol lookup failed.\n"); | |
| 26 | return -EINVAL; | |
| 27 | } | |
| 28 | return 0; | |
| 29 | } | |
| 30 | ||
| a8ad3613 MD |
31 | static |
| 32 | size_t prio_get_size(size_t offset) | |
| 33 | { | |
| 34 | size_t size = 0; | |
| 35 | ||
| 36 | size += lib_ring_buffer_align(offset, ltt_alignof(int)); | |
| 37 | size += sizeof(int); | |
| 38 | return size; | |
| 39 | } | |
| 40 | ||
| 41 | static | |
| 42 | void prio_record(struct lttng_ctx_field *field, | |
| 43 | struct lib_ring_buffer_ctx *ctx, | |
| 44 | struct ltt_channel *chan) | |
| 45 | { | |
| 46 | int prio; | |
| 47 | ||
| 8fefc8a2 | 48 | prio = wrapper_task_prio_sym(current); |
| 53f1f0ca MD |
49 | lib_ring_buffer_align_ctx(ctx, ltt_alignof(prio)); |
| 50 | chan->ops->event_write(ctx, &prio, sizeof(prio)); | |
| a8ad3613 MD |
51 | } |
| 52 | ||
| 53 | int lttng_add_prio_to_ctx(struct lttng_ctx **ctx) | |
| 54 | { | |
| 55 | struct lttng_ctx_field *field; | |
| 56 | int ret; | |
| 57 | ||
| 979133c5 MD |
58 | if (!wrapper_task_prio_sym) { |
| 59 | ret = wrapper_task_prio_init(); | |
| 60 | if (ret) | |
| 61 | return ret; | |
| 62 | } | |
| 63 | ||
| a8ad3613 MD |
64 | field = lttng_append_context(ctx); |
| 65 | if (!field) | |
| 09fec6b4 | 66 | return -ENOMEM; |
| 44252f0f MD |
67 | if (lttng_find_context(*ctx, "prio")) { |
| 68 | lttng_remove_context_field(ctx, field); | |
| 69 | return -EEXIST; | |
| 70 | } | |
| a8ad3613 MD |
71 | field->event_field.name = "prio"; |
| 72 | field->event_field.type.atype = atype_integer; | |
| 73 | field->event_field.type.u.basic.integer.size = sizeof(int) * CHAR_BIT; | |
| 74 | field->event_field.type.u.basic.integer.alignment = ltt_alignof(int) * CHAR_BIT; | |
| 75 | field->event_field.type.u.basic.integer.signedness = is_signed_type(int); | |
| 76 | field->event_field.type.u.basic.integer.reverse_byte_order = 0; | |
| 77 | field->event_field.type.u.basic.integer.base = 10; | |
| 78 | field->event_field.type.u.basic.integer.encoding = lttng_encode_none; | |
| 79 | field->get_size = prio_get_size; | |
| 80 | field->record = prio_record; | |
| 81 | wrapper_vmalloc_sync_all(); | |
| 82 | return 0; | |
| 83 | } | |
| 84 | EXPORT_SYMBOL_GPL(lttng_add_prio_to_ctx); | |
| 85 | ||
| 86 | MODULE_LICENSE("GPL and additional rights"); | |
| 87 | MODULE_AUTHOR("Mathieu Desnoyers"); | |
| 53f1f0ca | 88 | MODULE_DESCRIPTION("Linux Trace Toolkit Priority Context"); |