ftrace: add trace_special()
for ad-hoc tracing.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index d78cbc4..fa13059 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -137,6 +137,7 @@
TRACE_FN,
TRACE_CTX,
+ TRACE_SPECIAL,
__TRACE_LAST_TYPE
};
@@ -701,6 +702,22 @@
}
notrace void
+trace_special(struct trace_array *tr, struct trace_array_cpu *data,
+ unsigned long arg1, unsigned long arg2, unsigned long arg3)
+{
+ struct trace_entry *entry;
+
+ spin_lock(&data->lock);
+ entry = tracing_get_trace_entry(tr, data);
+ tracing_generic_entry_update(entry, 0);
+ entry->type = TRACE_SPECIAL;
+ entry->special.arg1 = arg1;
+ entry->special.arg2 = arg2;
+ entry->special.arg3 = arg3;
+ spin_unlock(&data->lock);
+}
+
+notrace void
tracing_sched_switch_trace(struct trace_array *tr,
struct trace_array_cpu *data,
struct task_struct *prev, struct task_struct *next,
@@ -1167,6 +1184,12 @@
entry->ctx.next_prio,
comm);
break;
+ case TRACE_SPECIAL:
+ trace_seq_printf(s, " %lx %lx %lx\n",
+ entry->special.arg1,
+ entry->special.arg2,
+ entry->special.arg3);
+ break;
default:
trace_seq_printf(s, "Unknown type %d\n", entry->type);
}
@@ -1234,6 +1257,14 @@
if (!ret)
return 0;
break;
+ case TRACE_SPECIAL:
+ ret = trace_seq_printf(s, " %lx %lx %lx\n",
+ entry->special.arg1,
+ entry->special.arg2,
+ entry->special.arg3);
+ if (!ret)
+ return 0;
+ break;
}
return 1;
}
@@ -1271,6 +1302,14 @@
if (!ret)
return 0;
break;
+ case TRACE_SPECIAL:
+ ret = trace_seq_printf(s, " %lx %lx %lx\n",
+ entry->special.arg1,
+ entry->special.arg2,
+ entry->special.arg3);
+ if (!ret)
+ return 0;
+ break;
}
return 1;
}
@@ -1304,6 +1343,11 @@
SEQ_PUT_FIELD_RET(s, entry->ctx.next_pid);
SEQ_PUT_FIELD_RET(s, entry->ctx.next_prio);
break;
+ case TRACE_SPECIAL:
+ SEQ_PUT_FIELD_RET(s, entry->special.arg1);
+ SEQ_PUT_FIELD_RET(s, entry->special.arg2);
+ SEQ_PUT_FIELD_RET(s, entry->special.arg3);
+ break;
}
return 1;
}
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 27fa2d0..7bdfef3 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -26,6 +26,15 @@
};
/*
+ * Special (free-form) trace entry:
+ */
+struct special_entry {
+ unsigned long arg1;
+ unsigned long arg2;
+ unsigned long arg3;
+};
+
+/*
* The trace entry - the most basic unit of tracing. This is what
* is printed in the end as a single line in the trace output, such as:
*
@@ -41,6 +50,7 @@
union {
struct ftrace_entry fn;
struct ctx_switch_entry ctx;
+ struct special_entry special;
};
};
@@ -154,6 +164,11 @@
struct task_struct *next,
unsigned long flags);
void tracing_record_cmdline(struct task_struct *tsk);
+void trace_special(struct trace_array *tr,
+ struct trace_array_cpu *data,
+ unsigned long arg1,
+ unsigned long arg2,
+ unsigned long arg3);
void tracing_start_function_trace(void);
void tracing_stop_function_trace(void);