tracing: Use var_refs[] for hist trigger reference checking

Since all the variable reference hist_fields are collected into
hist_data->var_refs[] array, there's no need to go through all the
fields looking for them, or in separate arrays like synth_var_refs[],
which will be going away soon anyway.

This also allows us to get rid of some unnecessary code and functions
currently used for the same purpose.

Link: http://lkml.kernel.org/r/1545246556.4239.7.camel@gmail.com
Acked-by: Namhyung Kim <namhyung@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 25d06b3..f3caf6e 100644 (file)
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -1297,75 +1297,29 @@ check_field_for_var_ref(struct hist_field *hist_field,
                        struct hist_trigger_data *var_data,
                        unsigned int var_idx)
 {
-       struct hist_field *found = NULL;
-
-       if (hist_field && hist_field->flags & HIST_FIELD_FL_VAR_REF) {
-               if (hist_field->var.idx == var_idx &&
-                   hist_field->var.hist_data == var_data) {
-                       found = hist_field;
-               }
-       }
-
-       return found;
-}
-
-static struct hist_field *
-check_field_for_var_refs(struct hist_trigger_data *hist_data,
-                        struct hist_field *hist_field,
-                        struct hist_trigger_data *var_data,
-                        unsigned int var_idx,
-                        unsigned int level)
-{
-       struct hist_field *found = NULL;
-       unsigned int i;
-
-       if (level > 3)
-               return found;
-
-       if (!hist_field)
-               return found;
-
-       found = check_field_for_var_ref(hist_field, var_data, var_idx);
-       if (found)
-               return found;
-
-       for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++) {
-               struct hist_field *operand;
+       WARN_ON(!(hist_field && hist_field->flags & HIST_FIELD_FL_VAR_REF));
 
-               operand = hist_field->operands[i];
-               found = check_field_for_var_refs(hist_data, operand, var_data,
-                                                var_idx, level + 1);
-               if (found)
-                       return found;
-       }
+       if (hist_field && hist_field->var.idx == var_idx &&
+           hist_field->var.hist_data == var_data)
+               return hist_field;
 
-       return found;
+       return NULL;
 }
 
 static struct hist_field *find_var_ref(struct hist_trigger_data *hist_data,
                                       struct hist_trigger_data *var_data,
                                       unsigned int var_idx)
 {
-       struct hist_field *hist_field, *found = NULL;
+       struct hist_field *hist_field;
        unsigned int i;
 
-       for_each_hist_field(i, hist_data) {
-               hist_field = hist_data->fields[i];
-               found = check_field_for_var_refs(hist_data, hist_field,
-                                                var_data, var_idx, 0);
-               if (found)
-                       return found;
-       }
-
-       for (i = 0; i < hist_data->n_synth_var_refs; i++) {
-               hist_field = hist_data->synth_var_refs[i];
-               found = check_field_for_var_refs(hist_data, hist_field,
-                                                var_data, var_idx, 0);
-               if (found)
-                       return found;
+       for (i = 0; i < hist_data->n_var_refs; i++) {
+               hist_field = hist_data->var_refs[i];
+               if (check_field_for_var_ref(hist_field, var_data, var_idx))
+                       return hist_field;
        }
 
-       return found;
+       return NULL;
 }
 
 static struct hist_field *find_any_var_ref(struct hist_trigger_data *hist_data,