Merge tag 'perf-core-for-mingo-4.11-20170213' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

New features:

 - Introduce the 'delta-abs' 'perf diff' compute method, that orders the
   histogram entries by the absolute value of the percentage delta for a
   function in two perf.data files, i.e. the functions that changed the
   most (increase or decrease in samples) comes first (Namhyung Kim)

User visible changes:

 - Improve message about tweaking the kernel.perf_event_paranoid setting,
   telling how to make the change permanent by editing /etc/sysctl.conf
   (Arnaldo Carvalho de Melo)

Infrastructure changes:

 - Introduce linux/compiler-gcc.h as a counterpart to the kernel's,
   initially containing the definition of __fallthrough, more to
   come (__maybe_unused, etc) (Arnaldo Carvalho de Melo)

 - Fixes for problems uncovered by building tools/perf with clang, such
   as always true tests of arrays against NULL and variables that sometimes
   were used without being initialized (Arnaldo Carvalho de Melo, Steven Rostedt)

 - Before loading a new ELF, clear global variables set by the
   samples/bpf loader (Mickaël Salaün)

 - Ignore already processed ELF sections in the samples/bpf
   loader (Mickaël Salaün)

 - Fix compile error in the scripting code with some perl5
   versions (Wang YanQing)

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

7 files changed, 10 insertions, 9 deletions

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 04e536ae4d88..cd2fb42e5dd4 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2469,7 +2469,9 @@ int perf_evsel__open_strerror(struct perf_evsel *evsel, struct target *target,
 		 "  -1: Allow use of (almost) all events by all users\n"
 		 ">= 0: Disallow raw tracepoint access by users without CAP_IOC_LOCK\n"
 		 ">= 1: Disallow CPU event access by users without CAP_SYS_ADMIN\n"
-		 ">= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN",
+		 ">= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN\n\n"
+		 "To make this setting permanent, edit /etc/sysctl.conf too, e.g.:\n\n"
+		 "	kernel.perf_event_paranoid = -1\n" ,
 				 target->system_wide ? "system-wide " : "",
 				 perf_event_paranoid());
 	case ENOENT:
diff --git a/tools/perf/util/evsel_fprintf.c b/tools/perf/util/evsel_fprintf.c
index 6b2925542c0a..4ef5184819a0 100644
--- a/tools/perf/util/evsel_fprintf.c
+++ b/tools/perf/util/evsel_fprintf.c
@@ -168,7 +168,6 @@ int sample__fprintf_callchain(struct perf_sample *sample, int left_alignment,
 
 			if (symbol_conf.bt_stop_list &&
 			    node->sym &&
-			    node->sym->name &&
 			    strlist__has_entry(symbol_conf.bt_stop_list,
 					       node->sym->name)) {
 				break;
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 747a034d1ff3..a1043cf9b89c 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -1565,7 +1565,7 @@ int machine__process_event(struct machine *machine, union perf_event *event,
 
 static bool symbol__match_regex(struct symbol *sym, regex_t *regex)
 {
-	if (sym->name && !regexec(regex, sym->name, 0, NULL, 0))
+	if (!regexec(regex, sym->name, 0, NULL, 0))
 		return 1;
 	return 0;
 }
diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index 4f9a71c63026..0a943e7b1ea7 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -387,10 +387,10 @@ size_t map__fprintf_dsoname(struct map *map, FILE *fp)
 {
 	const char *dsoname = "[unknown]";
 
-	if (map && map->dso && (map->dso->name || map->dso->long_name)) {
+	if (map && map->dso) {
 		if (symbol_conf.show_kernel_path && map->dso->long_name)
 			dsoname = map->dso->long_name;
-		else if (map->dso->name)
+		else
 			dsoname = map->dso->name;
 	}
 
diff --git a/tools/perf/util/scripting-engines/Build b/tools/perf/util/scripting-engines/Build
index 6516e220c247..82d28c67e0f3 100644
--- a/tools/perf/util/scripting-engines/Build
+++ b/tools/perf/util/scripting-engines/Build
@@ -1,6 +1,6 @@
 libperf-$(CONFIG_LIBPERL)   += trace-event-perl.o
 libperf-$(CONFIG_LIBPYTHON) += trace-event-python.o
 
-CFLAGS_trace-event-perl.o += $(PERL_EMBED_CCOPTS) -Wno-redundant-decls -Wno-strict-prototypes -Wno-unused-parameter -Wno-shadow -Wno-undef -Wno-switch-default
+CFLAGS_trace-event-perl.o += $(PERL_EMBED_CCOPTS) -Wno-redundant-decls -Wno-strict-prototypes -Wno-unused-parameter -Wno-shadow -Wno-nested-externs -Wno-undef -Wno-switch-default
 
 CFLAGS_trace-event-python.o += $(PYTHON_EMBED_CCOPTS) -Wno-redundant-decls -Wno-strict-prototypes -Wno-unused-parameter -Wno-shadow
diff --git a/tools/perf/util/scripting-engines/trace-event-perl.c b/tools/perf/util/scripting-engines/trace-event-perl.c
index 014ecd6f67c4..c1555fd0035a 100644
--- a/tools/perf/util/scripting-engines/trace-event-perl.c
+++ b/tools/perf/util/scripting-engines/trace-event-perl.c
@@ -309,10 +309,10 @@ static SV *perl_process_callchain(struct perf_sample *sample,
 		if (node->map) {
 			struct map *map = node->map;
 			const char *dsoname = "[unknown]";
-			if (map && map->dso && (map->dso->name || map->dso->long_name)) {
+			if (map && map->dso) {
 				if (symbol_conf.show_kernel_path && map->dso->long_name)
 					dsoname = map->dso->long_name;
-				else if (map->dso->name)
+				else
 					dsoname = map->dso->name;
 			}
 			if (!hv_stores(elem, "dso", newSVpv(dsoname,0))) {
diff --git a/tools/perf/util/symbol_fprintf.c b/tools/perf/util/symbol_fprintf.c
index 7c6b33e8e2d2..63694e174e5c 100644
--- a/tools/perf/util/symbol_fprintf.c
+++ b/tools/perf/util/symbol_fprintf.c
@@ -21,7 +21,7 @@ size_t __symbol__fprintf_symname_offs(const struct symbol *sym,
 	unsigned long offset;
 	size_t length;
 
-	if (sym && sym->name) {
+	if (sym) {
 		length = fprintf(fp, "%s", sym->name);
 		if (al && print_offsets) {
 			if (al->addr < sym->end)