perf symbols: Mark if a symbol is idle in the library

This was being done just in 'perf top', but grouping idle symbols should
be useful in other places as well, so remove one more symbol_filter_t
user by moving this to the symbol library.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-5r7xitjkzjr9jak1zy3d8u5l@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-top.c

@@ -679,9 +679,6 @@ static int symbol_filter(struct map *map, struct symbol *sym)
 	    strstr(name, "_text_end"))
 		return 1;
 
-	if (symbol__is_idle(sym))
-		sym->idle = 1;
-
 	return 0;
 }
 

tools/perf/util/symbol-elf.c

@@ -1127,7 +1127,7 @@ new_symbol:
 		if (filter && filter(curr_map, f))
 			symbol__delete(f);
 		else {
-			symbols__insert(&curr_dso->symbols[curr_map->type], f);
+			__symbols__insert(&curr_dso->symbols[curr_map->type], f, dso->kernel);
 			nr++;
 		}
 	}

tools/perf/util/symbol.c

@@ -28,6 +28,8 @@ static int dso__load_kernel_sym(struct dso *dso, struct map *map,
 				symbol_filter_t filter);
 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map,
 			symbol_filter_t filter);
+static bool symbol__is_idle(const char *name);
+
 int vmlinux_path__nr_entries;
 char **vmlinux_path;
 
@@ -277,13 +279,24 @@ void symbols__delete(struct rb_root *symbols)
 	}
 }
 
-void symbols__insert(struct rb_root *symbols, struct symbol *sym)
+void __symbols__insert(struct rb_root *symbols, struct symbol *sym, bool kernel)
 {
 	struct rb_node **p = &symbols->rb_node;
 	struct rb_node *parent = NULL;
 	const u64 ip = sym->start;
 	struct symbol *s;
 
+	if (kernel) {
+		const char *name = sym->name;
+		/*
+		 * ppc64 uses function descriptors and appends a '.' to the
+		 * start of every instruction address. Remove it.
+		 */
+		if (name[0] == '.')
+			name++;
+		sym->idle = symbol__is_idle(name);
+	}
+
 	while (*p != NULL) {
 		parent = *p;
 		s = rb_entry(parent, struct symbol, rb_node);
@@ -296,6 +309,11 @@ void symbols__insert(struct rb_root *symbols, struct symbol *sym)
 	rb_insert_color(&sym->rb_node, symbols);
 }
 
+void symbols__insert(struct rb_root *symbols, struct symbol *sym)
+{
+	__symbols__insert(symbols, sym, false);
+}
+
 static struct symbol *symbols__find(struct rb_root *symbols, u64 ip)
 {
 	struct rb_node *n;
@@ -424,7 +442,7 @@ void dso__reset_find_symbol_cache(struct dso *dso)
 
 void dso__insert_symbol(struct dso *dso, enum map_type type, struct symbol *sym)
 {
-	symbols__insert(&dso->symbols[type], sym);
+	__symbols__insert(&dso->symbols[type], sym, dso->kernel);
 
 	/* update the symbol cache if necessary */
 	if (dso->last_find_result[type].addr >= sym->start &&
@@ -546,7 +564,7 @@ struct process_kallsyms_args {
  * These are symbols in the kernel image, so make sure that
  * sym is from a kernel DSO.
  */
-bool symbol__is_idle(struct symbol *sym)
+static bool symbol__is_idle(const char *name)
 {
 	const char * const idle_symbols[] = {
 		"cpu_idle",
@@ -563,14 +581,10 @@ bool symbol__is_idle(struct symbol *sym)
 		"pseries_dedicated_idle_sleep",
 		NULL
 	};
-
 	int i;
 
-	if (!sym)
-		return false;
-
 	for (i = 0; idle_symbols[i]; i++) {
-		if (!strcmp(idle_symbols[i], sym->name))
+		if (!strcmp(idle_symbols[i], name))
 			return true;
 	}
 
@@ -599,7 +613,7 @@ static int map__process_kallsym_symbol(void *arg, const char *name,
 	 * We will pass the symbols to the filter later, in
 	 * map__split_kallsyms, when we have split the maps per module
 	 */
-	symbols__insert(root, sym);
+	__symbols__insert(root, sym, !strchr(name, '['));
 
 	return 0;
 }

tools/perf/util/symbol.h

@@ -294,7 +294,6 @@ size_t symbol__fprintf(struct symbol *sym, FILE *fp);
 bool symbol_type__is_a(char symbol_type, enum map_type map_type);
 bool symbol__restricted_filename(const char *filename,
 				 const char *restricted_filename);
-bool symbol__is_idle(struct symbol *sym);
 int symbol__config_symfs(const struct option *opt __maybe_unused,
 			 const char *dir, int unset __maybe_unused);
 
@@ -304,6 +303,7 @@ int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss,
 int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss,
 				struct map *map, symbol_filter_t filter);
 
+void __symbols__insert(struct rb_root *symbols, struct symbol *sym, bool kernel);
 void symbols__insert(struct rb_root *symbols, struct symbol *sym);
 void symbols__fixup_duplicate(struct rb_root *symbols);
 void symbols__fixup_end(struct rb_root *symbols);