X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=lttng-context-prio.c;h=ad1c42f43ef5d56ed638ec76087ff1048b2b2992;hb=6d20e0ae80b64714a2e768d9ef110e13c0b43c4a;hp=a748929a609c826ced34fb9b8c8a766e8e1b4c15;hpb=a8ad3613f2e0e272487b8ec0f0ec8e3c6da689f9;p=lttng-modules.git

diff --git a/lttng-context-prio.c b/lttng-context-prio.c
index a748929a..ad1c42f4 100644
--- a/lttng-context-prio.c
+++ b/lttng-context-prio.c
@@ -15,6 +15,19 @@
 #include "wrapper/vmalloc.h"
 #include "ltt-tracer.h"
 
+static
+int (*wrapper_task_prio_sym)(struct task_struct *t);
+
+int wrapper_task_prio_init(void)
+{
+	wrapper_task_prio_sym = (void *) kallsyms_lookup_name("task_prio");
+	if (!wrapper_task_prio_sym) {
+		printk(KERN_WARNING "LTTng: task_prio symbol lookup failed.\n");
+		return -EINVAL;
+	}
+	return 0;
+}
+
 static
 size_t prio_get_size(size_t offset)
 {
@@ -32,9 +45,9 @@ void prio_record(struct lttng_ctx_field *field,
 {
 	int prio;
 
-	pid = p->prio - MAX_RT_PRIO;
-	lib_ring_buffer_align_ctx(ctx, ltt_alignof(pid));
-	chan->ops->event_write(ctx, &pid, sizeof(pid));
+	prio = wrapper_task_prio_sym(current);
+	lib_ring_buffer_align_ctx(ctx, ltt_alignof(prio));
+	chan->ops->event_write(ctx, &prio, sizeof(prio));
 }
 
 int lttng_add_prio_to_ctx(struct lttng_ctx **ctx)
@@ -42,9 +55,19 @@ int lttng_add_prio_to_ctx(struct lttng_ctx **ctx)
 	struct lttng_ctx_field *field;
 	int ret;
 
+	if (!wrapper_task_prio_sym) {
+		ret = wrapper_task_prio_init();
+		if (ret)
+			return ret;
+	}
+
 	field = lttng_append_context(ctx);
 	if (!field)
-		return ret;
+		return -ENOMEM;
+	if (lttng_find_context(*ctx, "prio")) {
+		lttng_remove_context_field(ctx, field);
+		return -EEXIST;
+	}
 	field->event_field.name = "prio";
 	field->event_field.type.atype = atype_integer;
 	field->event_field.type.u.basic.integer.size = sizeof(int) * CHAR_BIT;
@@ -62,4 +85,4 @@ EXPORT_SYMBOL_GPL(lttng_add_prio_to_ctx);
 
 MODULE_LICENSE("GPL and additional rights");
 MODULE_AUTHOR("Mathieu Desnoyers");
-MODULE_DESCRIPTION("Linux Trace Toolkit Perf Support");
+MODULE_DESCRIPTION("Linux Trace Toolkit Priority Context");