On Fri, 10 Jan 2020 14:35:12 -0600
Tom Zanussi <zanussi@xxxxxxxxxx> wrote:
> 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@xxxxxxxxxx>
> ---
> 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.
-- Steve
> +
> /*
> * Event file flags:
> * ENABLED - The event is enabled
