Hi Steve,

On Tue, 2020-01-21 at 11:57 -0500, Steven Rostedt wrote:

On Fri, 10 Jan 2020 14:35:12 -0600
Tom Zanussi [off-list ref] wrote:

quoted

Add functions used to generate synthetic event commands, built on
top
of the dynevent_cmd interface.

gen_synth_cmd() is used to create a synthetic event command using a
variable arg list and gen_synth_cmd_array() does the same thing but
using an array of field descriptors.  add_synth_field() and
add_synth_fields() can be used to add single fields one by one or
as a
group.  Once all desired fields are added, create_dynevent() is
used
to actually execute the command and create the event.

create_synth_event() does everything, including creating the event,
in
a single call.

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
---
 include/linux/trace_events.h     |  30 ++++
 kernel/trace/trace_events_hist.c | 325
++++++++++++++++++++++++++++++++++++++-
 2 files changed, 352 insertions(+), 3 deletions(-)

diff --git a/include/linux/trace_events.h

b/include/linux/trace_events.h
index bf4cc2e56125..4228407d4736 100644

--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h

@@ -409,6 +409,36 @@ extern int create_dynevent(struct dynevent_cmd

*cmd);
 
 extern int delete_synth_event(const char *name);
 
+extern void synth_dynevent_cmd_init(struct dynevent_cmd *cmd,
+				    char *buf, int maxlen);
+
+extern int __gen_synth_cmd(struct dynevent_cmd *cmd, const char
*name,
+			   struct module *mod, ...);
+
+#define gen_synth_cmd(cmd, name, mod, ...)	\
+	__gen_synth_cmd(cmd, name, mod, ## __VA_ARGS__, NULL)
+
+struct synth_field_desc {
+	const char *type;
+	const char *name;
+};
+
+extern int gen_synth_cmd_array(struct dynevent_cmd *cmd, const
char *name,
+			       struct module *mod,
+			       struct synth_field_desc *fields,
+			       unsigned int n_fields);
+extern int create_synth_event(const char *name,
+			      struct synth_field_desc *fields,
+			      unsigned int n_fields, struct module
*mod);
+
+
+extern int add_synth_field(struct dynevent_cmd *cmd,
+			   const char *type,
+			   const char *name);
+extern int add_synth_fields(struct dynevent_cmd *cmd,
+			    struct synth_field_desc *fields,
+			    unsigned int n_fields);

As these are in a global header and globally visible, let's rename
them
to be more name space aware.

Have them all start with "synth_event_".

synth_event_gen_cmd_array()
synth_event_create()
synth_event_add_field()
synth_event_add_fields()

Makes it easier to grep for synth_event functions too.

OK, will do.

Thanks,

Tom

-- Steve

quoted

+
 /*
  * Event file flags:
  *  ENABLED	  - The event is enabled