tracing: Add TRACE_CUSTOM_EVENT() macro

[linux-2.6-block.git] / samples / trace_events / trace_custom_sched.h

diff --git a/samples/trace_events/trace_custom_sched.h b/samples/trace_events/trace_custom_sched.h
new file mode 100644 (file)
index 0000000..a3d14de
--- /dev/null
+++ b/samples/trace_events/trace_custom_sched.h
@@ -0,0 +1,95 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Like the headers that use TRACE_EVENT(), the TRACE_CUSTOM_EVENT()
+ * needs a header that allows for multiple inclusions.
+ *
+ * Test for a unique name (here we have _TRACE_CUSTOM_SCHED_H),
+ * also allowing to continue if TRACE_CUSTOM_MULTI_READ is defined.
+ */
+#if !defined(_TRACE_CUSTOM_SCHED_H) || defined(TRACE_CUSTOM_MULTI_READ)
+#define _TRACE_CUSTOM_SCHED_H
+
+/* Include linux/trace_events.h for initial defines of TRACE_CUSTOM_EVENT() */
+#include <linux/trace_events.h>
+
+/*
+ * TRACE_CUSTOM_EVENT() is just like TRACE_EVENT(). The first parameter
+ * is the event name of an existing event where the TRACE_EVENT has been included
+ * in the C file before including this file.
+ */
+TRACE_CUSTOM_EVENT(sched_switch,
+
+       /*
+        * The TP_PROTO() and TP_ARGS must match the trace event
+        * that the custom event is using.
+        */
+       TP_PROTO(bool preempt,
+                struct task_struct *prev,
+                struct task_struct *next),
+
+       TP_ARGS(preempt, prev, next),
+
+       /*
+        * The next fields are where the customization happens.
+        * The TP_STRUCT__entry() defines what will be recorded
+        * in the ring buffer when the custom event triggers.
+        *
+        * The rest is just like the TRACE_EVENT() macro except that
+        * it uses the custom entry.
+        */
+       TP_STRUCT__entry(
+               __field(        unsigned short,         prev_prio       )
+               __field(        unsigned short,         next_prio       )
+               __field(        pid_t,  next_pid                        )
+       ),
+
+       TP_fast_assign(
+               __entry->prev_prio      = prev->prio;
+               __entry->next_pid       = next->pid;
+               __entry->next_prio      = next->prio;
+       ),
+
+       TP_printk("prev_prio=%d next_pid=%d next_prio=%d",
+                 __entry->prev_prio, __entry->next_pid, __entry->next_prio)
+)
+
+
+TRACE_CUSTOM_EVENT(sched_waking,
+
+       TP_PROTO(struct task_struct *p),
+
+       TP_ARGS(p),
+
+       TP_STRUCT__entry(
+               __field(        pid_t,                  pid     )
+               __field(        unsigned short,         prio    )
+       ),
+
+       TP_fast_assign(
+               __entry->pid    = p->pid;
+               __entry->prio   = p->prio;
+       ),
+
+       TP_printk("pid=%d prio=%d", __entry->pid, __entry->prio)
+)
+#endif
+/*
+ * Just like the headers that create TRACE_EVENTs, the below must
+ * be outside the protection of the above #if block.
+ */
+
+/*
+ * It is required that the Makefile includes:
+ *    CFLAGS_<c_file>.o := -I$(src)
+ */
+#undef TRACE_INCLUDE_PATH
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_PATH .
+
+/*
+ * It is requred that the TRACE_INCLUDE_FILE be the same
+ * as this file without the ".h".
+ */
+#define TRACE_INCLUDE_FILE trace_custom_sched
+#include <trace/define_custom_trace.h>