perf machine: No need to check if kernel module maps pre-exist

We'only populating maps for kernel modules either from perf.data file
PERF_RECORD_MMAP records or when parsing /proc/modules, so there is no
need to first look if we already have those module maps in the list,
that would mean the kernel has duplicate entries.

So ditch one use of looking up maps by name.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-gnzjg2hhuz6jnrw91m35059y@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/machine.c

@@ -772,20 +772,16 @@ int machine__process_ksymbol(struct machine *machine __maybe_unused,
 	return machine__process_ksymbol_register(machine, event, sample);
 }
 
-struct map *machine__findnew_module_map(struct machine *machine, u64 start,
+static struct map *machine__addnew_module_map(struct machine *machine, u64 start,
 					      const char *filename)
 {
 	struct map *map = NULL;
-	struct dso *dso = NULL;
 	struct kmod_path m;
+	struct dso *dso;
 
 	if (kmod_path__parse_name(&m, filename))
 		return NULL;
 
-	map = map_groups__find_by_name(&machine->kmaps, m.name);
-	if (map)
-		goto out;
-
 	dso = machine__findnew_module_dso(machine, &m, filename);
 	if (dso == NULL)
 		goto out;
@@ -1384,7 +1380,7 @@ static int machine__create_module(void *arg, const char *name, u64 start,
 	if (arch__fix_module_text_start(&start, &size, name) < 0)
 		return -1;
 
-	map = machine__findnew_module_map(machine, start, name);
+	map = machine__addnew_module_map(machine, start, name);
 	if (map == NULL)
 		return -1;
 	map->end = start + size;
@@ -1559,7 +1555,7 @@ static int machine__process_kernel_mmap_event(struct machine *machine,
 				strlen(machine->mmap_name) - 1) == 0;
 	if (event->mmap.filename[0] == '/' ||
 	    (!is_kernel_mmap && event->mmap.filename[0] == '[')) {
-		map = machine__findnew_module_map(machine, event->mmap.start,
+		map = machine__addnew_module_map(machine, event->mmap.start,
 						 event->mmap.filename);
 		if (map == NULL)
 			goto out_problem;

tools/perf/util/machine.h

@@ -221,8 +221,6 @@ struct symbol *machine__find_kernel_symbol_by_name(struct machine *machine,
 	return map_groups__find_symbol_by_name(&machine->kmaps, name, mapp);
 }
 
-struct map *machine__findnew_module_map(struct machine *machine, u64 start,
-					const char *filename);
 int arch__fix_module_text_start(u64 *start, u64 *size, const char *name);
 
 int machine__load_kallsyms(struct machine *machine, const char *filename);

tools/perf/util/symbol.c

@@ -1530,7 +1530,7 @@ static bool dso__is_compatible_symtab_type(struct dso *dso, bool kmod,
 	case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP:
 		/*
 		 * kernel modules know their symtab type - it's set when
-		 * creating a module dso in machine__findnew_module_map().
+		 * creating a module dso in machine__addnew_module_map().
 		 */
 		return kmod && dso->symtab_type == type;