Add prio and nice contexts

[lttng-modules.git] / lttng-context-nice.c

diff --git a/lttng-context-nice.c b/lttng-context-nice.c
new file mode 100644 (file)
index 0000000..d7fafb9
--- /dev/null
+++ b/lttng-context-nice.c
@@ -0,0 +1,65 @@
+/*
+ * (C) Copyright       2009-2011 -
+ *             Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * LTTng nice context.
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include "ltt-events.h"
+#include "wrapper/ringbuffer/frontend_types.h"
+#include "wrapper/vmalloc.h"
+#include "ltt-tracer.h"
+
+static
+size_t nice_get_size(size_t offset)
+{
+       size_t size = 0;
+
+       size += lib_ring_buffer_align(offset, ltt_alignof(int));
+       size += sizeof(int);
+       return size;
+}
+
+static
+void nice_record(struct lttng_ctx_field *field,
+               struct lib_ring_buffer_ctx *ctx,
+               struct ltt_channel *chan)
+{
+       int nice;
+
+       nice = task_nice(current);
+       lib_ring_buffer_align_ctx(ctx, ltt_alignof(nice));
+       chan->ops->event_write(ctx, &nice, sizeof(nice));
+}
+
+int lttng_add_nice_to_ctx(struct lttng_ctx **ctx)
+{
+       struct lttng_ctx_field *field;
+       int ret;
+
+       field = lttng_append_context(ctx);
+       if (!field)
+               return ret;
+       field->event_field.name = "nice";
+       field->event_field.type.atype = atype_integer;
+       field->event_field.type.u.basic.integer.size = sizeof(int) * CHAR_BIT;
+       field->event_field.type.u.basic.integer.alignment = ltt_alignof(int) * CHAR_BIT;
+       field->event_field.type.u.basic.integer.signedness = is_signed_type(int);
+       field->event_field.type.u.basic.integer.reverse_byte_order = 0;
+       field->event_field.type.u.basic.integer.base = 10;
+       field->event_field.type.u.basic.integer.encoding = lttng_encode_none;
+       field->get_size = nice_get_size;
+       field->record = nice_record;
+       wrapper_vmalloc_sync_all();
+       return 0;
+}
+EXPORT_SYMBOL_GPL(lttng_add_nice_to_ctx);
+
+MODULE_LICENSE("GPL and additional rights");
+MODULE_AUTHOR("Mathieu Desnoyers");
+MODULE_DESCRIPTION("Linux Trace Toolkit Nice Context");