On Thu, 10 Dec 2015 12:50:48 -0600 Tom Zanussi <[email protected]> wrote:
> Add a new needs_rec flag for triggers that require unconditional > access to trace records in order to function. > > Normally a trigger requires access to the contents of a trace record > only if it has a filter associated with it (since filters need the > contents of a record in order to make a filtering decision). Some > types of triggers, such as 'hist' triggers, require access to trace > record contents independent of the presence of filters, so add a new > flag for those triggers. > > Signed-off-by: Tom Zanussi <[email protected]> > Tested-by: Masami Hiramatsu <[email protected]> > Reviewed-by: Namhyung Kim <[email protected]> > --- > kernel/trace/trace.h | 7 +++++++ > kernel/trace/trace_events_trigger.c | 3 ++- > 2 files changed, 9 insertions(+), 1 deletion(-) > > diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h > index 5e23a97..300add5 100644 > --- a/kernel/trace/trace.h > +++ b/kernel/trace/trace.h > @@ -1293,6 +1293,12 @@ struct event_trigger_ops { > * itself logs to the trace buffer, this flag should be set, > * otherwise it can be left unspecified. > * > + * @needs_rec: A flag that says whether or not this command needs > + * access to the trace record in order to perform its function, > + * regardless of whether or not it has a filter associated with > + * it (filters make a trigger require access to the trace record > + * but are not always present). > + * > * All the methods below, except for @set_filter(), must be > * implemented. > * > @@ -1333,6 +1339,7 @@ struct event_command { > char *name; > enum event_trigger_type trigger_type; > bool post_trigger; > + bool needs_rec; Note, from what I understand, gcc sucks with bool in structures. Best thing to do here is to create a "int flags" field, and check the result with masks. You don't need to update this patch (I'm still working on the series), but a patch on top of these may be necessary. I could add the patch too. -- Steve > int (*func)(struct event_command *cmd_ops, > struct trace_event_file *file, > char *glob, char *cmd, char *params); > diff --git a/kernel/trace/trace_events_trigger.c > b/kernel/trace/trace_events_trigger.c > index 8375d29..2f881e9 100644 > --- a/kernel/trace/trace_events_trigger.c > +++ b/kernel/trace/trace_events_trigger.c > @@ -498,7 +498,8 @@ void update_cond_flag(struct trace_event_file *file) > bool set_cond = false; > > list_for_each_entry_rcu(data, &file->triggers, list) { > - if (data->filter || data->cmd_ops->post_trigger) { > + if (data->filter || data->cmd_ops->post_trigger || > + data->cmd_ops->needs_rec) { > set_cond = true; > break; > }
