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 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -137,6 +137,7 @@ enum trace_type {
 
        TRACE_FN,
        TRACE_CTX,
+       TRACE_SPECIAL,
 
        __TRACE_LAST_TYPE
 };
@@ -701,6 +702,22 @@ ftrace(struct trace_array *tr, struct trace_array_cpu *data,
 }
 
 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 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
                                 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 @@ static notrace int print_trace_fmt(struct trace_iterator *iter)
                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 @@ static notrace int print_raw_fmt(struct trace_iterator *iter)
                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 @@ static notrace int print_bin_fmt(struct trace_iterator *iter)
                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 (file)
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -26,6 +26,15 @@ struct ctx_switch_entry {
 };
 
 /*
+ * 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 @@ struct trace_entry {
        union {
                struct ftrace_entry             fn;
                struct ctx_switch_entry         ctx;
+               struct special_entry            special;
        };
 };
 
@@ -154,6 +164,11 @@ void tracing_sched_switch_trace(struct trace_array *tr,
                                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);