perf/core improvements and fixes:

User visible:
 
 - Fix bug 'perf stat' in handling events in error state (Stephane Eranian)
 
 Documentation:
 
 - Add usage of --no-syscalls in 'perf trace' man page (Ravi Bangoria)
 
 Infrastructure:
 
 - Pass PYTHON config to feature detection (David Carrillo-Cisneros)
 
 - Disable JVMTI if no ELF support available (David Carrillo-Cisneros)
 
 - Fix feature detection redefinion of build flags (David Carrillo-Cisneros)
 
 - Hint missing file when tool tips fail to load (David Carrillo-Cisneros)
 
 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Merge tag 'perf-core-for-mingo-4.12-20170413' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

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

User visible changes:

 - Fix 'perf stat' bug in handling events in error state (Stephane Eranian)

Documentation changes:

 - Add usage of --no-syscalls in 'perf trace' man page (Ravi Bangoria)

Infrastructure changes:

 - Pass PYTHON config to feature detection (David Carrillo-Cisneros)

 - Disable JVMTI if no ELF support available (David Carrillo-Cisneros)

 - Fix feature detection redefinion of build flags (David Carrillo-Cisneros)

 - Hint missing file when tool tips fail to load (David Carrillo-Cisneros)

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

tools/build/feature/Makefile

@@ -53,17 +53,17 @@ FILES=                                          \
 
 FILES := $(addprefix $(OUTPUT),$(FILES))
 
-CC ?= $(CROSS_COMPILE)gcc -MD
-CXX ?= $(CROSS_COMPILE)g++ -MD
-PKG_CONFIG := $(CROSS_COMPILE)pkg-config
+CC ?= $(CROSS_COMPILE)gcc
+CXX ?= $(CROSS_COMPILE)g++
+PKG_CONFIG ?= $(CROSS_COMPILE)pkg-config
 LLVM_CONFIG ?= llvm-config
 
 all: $(FILES)
 
-__BUILD = $(CC) $(CFLAGS) -Wall -Werror -o $@ $(patsubst %.bin,%.c,$(@F)) $(LDFLAGS)
+__BUILD = $(CC) $(CFLAGS) -MD -Wall -Werror -o $@ $(patsubst %.bin,%.c,$(@F)) $(LDFLAGS)
   BUILD = $(__BUILD) > $(@:.bin=.make.output) 2>&1
 
-__BUILDXX = $(CXX) $(CXXFLAGS) -Wall -Werror -o $@ $(patsubst %.bin,%.cpp,$(@F)) $(LDFLAGS)
+__BUILDXX = $(CXX) $(CXXFLAGS) -MD -Wall -Werror -o $@ $(patsubst %.bin,%.cpp,$(@F)) $(LDFLAGS)
   BUILDXX = $(__BUILDXX) > $(@:.bin=.make.output) 2>&1
 
 ###############################
@@ -175,7 +175,7 @@ $(OUTPUT)test-libperl.bin:
 	$(BUILD) $(FLAGS_PERL_EMBED)
 
 $(OUTPUT)test-libpython.bin:
-	$(BUILD)
+	$(BUILD) $(FLAGS_PYTHON_EMBED)
 
 $(OUTPUT)test-libpython-version.bin:
 	$(BUILD)

tools/perf/Documentation/perf-trace.txt

@@ -123,7 +123,8 @@ the thread executes on the designated CPUs. Default is to monitor all CPUs.
 	major or all pagefaults. Default value is maj.
 
 --syscalls::
-	Trace system calls. This options is enabled by default.
+	Trace system calls. This options is enabled by default, disable with
+	--no-syscalls.
 
 --call-graph [mode,type,min[,limit],order[,key][,branch]]::
         Setup and enable call-graph (stack chain/backtrace) recording.

tools/perf/Makefile.config

@@ -170,14 +170,21 @@ PYTHON2_CONFIG := \
 override PYTHON_CONFIG := \
   $(call get-executable-or-default,PYTHON_CONFIG,$(PYTHON2_CONFIG))
 
+grep-libs  = $(filter -l%,$(1))
+strip-libs  = $(filter-out -l%,$(1))
+
 PYTHON_CONFIG_SQ := $(call shell-sq,$(PYTHON_CONFIG))
 
+ifdef PYTHON_CONFIG
   PYTHON_EMBED_LDOPTS := $(shell $(PYTHON_CONFIG_SQ) --ldflags 2>/dev/null)
+  PYTHON_EMBED_LDFLAGS := $(call strip-libs,$(PYTHON_EMBED_LDOPTS))
+  PYTHON_EMBED_LIBADD := $(call grep-libs,$(PYTHON_EMBED_LDOPTS)) -lutil
   PYTHON_EMBED_CCOPTS := $(shell $(PYTHON_CONFIG_SQ) --cflags 2>/dev/null)
-
   ifeq ($(CC), clang)
     PYTHON_EMBED_CCOPTS := $(filter-out -specs=%,$(PYTHON_EMBED_CCOPTS))
   endif
+  FLAGS_PYTHON_EMBED := $(PYTHON_EMBED_CCOPTS) $(PYTHON_EMBED_LDOPTS)
+endif
 
 FEATURE_CHECK_CFLAGS-libpython := $(PYTHON_EMBED_CCOPTS)
 FEATURE_CHECK_LDFLAGS-libpython := $(PYTHON_EMBED_LDOPTS)
@@ -267,6 +274,7 @@ ifdef NO_LIBELF
   NO_LIBUNWIND := 1
   NO_LIBDW_DWARF_UNWIND := 1
   NO_LIBBPF := 1
+  NO_JVMTI := 1
 else
   ifeq ($(feature-libelf), 0)
     ifeq ($(feature-glibc), 1)
@@ -276,7 +284,7 @@ else
       LIBC_SUPPORT := 1
     endif
     ifeq ($(LIBC_SUPPORT),1)
-      msg := $(warning No libelf found, disables 'probe' tool and BPF support in 'perf record', please install libelf-dev, libelf-devel or elfutils-libelf-devel);
+      msg := $(warning No libelf found. Disables 'probe' tool, jvmti and BPF support in 'perf record'. Please install libelf-dev, libelf-devel or elfutils-libelf-devel);
 
       NO_LIBELF := 1
       NO_DWARF := 1
@@ -284,6 +292,7 @@ else
       NO_LIBUNWIND := 1
       NO_LIBDW_DWARF_UNWIND := 1
       NO_LIBBPF := 1
+      NO_JVMTI := 1
     else
       ifneq ($(filter s% -static%,$(LDFLAGS),),)
         msg := $(error No static glibc found, please install glibc-static);
@@ -554,8 +563,6 @@ ifndef NO_GTK2
   endif
 endif
 
-grep-libs  = $(filter -l%,$(1))
-strip-libs = $(filter-out -l%,$(1))
 
 ifdef NO_LIBPERL
   CFLAGS += -DNO_LIBPERL
@@ -603,21 +610,9 @@ else
       $(call disable-python,No 'python-config' tool was found: disables Python support - please install python-devel/python-dev)
     else
 
-      PYTHON_CONFIG_SQ := $(call shell-sq,$(PYTHON_CONFIG))
-
-      PYTHON_EMBED_LDOPTS := $(shell $(PYTHON_CONFIG_SQ) --ldflags 2>/dev/null)
-      PYTHON_EMBED_LDFLAGS := $(call strip-libs,$(PYTHON_EMBED_LDOPTS))
-      PYTHON_EMBED_LIBADD := $(call grep-libs,$(PYTHON_EMBED_LDOPTS)) -lutil
-      PYTHON_EMBED_CCOPTS := $(shell $(PYTHON_CONFIG_SQ) --cflags 2>/dev/null)
-      ifeq ($(CC), clang)
-        PYTHON_EMBED_CCOPTS := $(filter-out -specs=%,$(PYTHON_EMBED_CCOPTS))
-      endif
-      FLAGS_PYTHON_EMBED := $(PYTHON_EMBED_CCOPTS) $(PYTHON_EMBED_LDOPTS)
-
       ifneq ($(feature-libpython), 1)
         $(call disable-python,No 'Python.h' (for Python 2.x support) was found: disables Python support - please install python-devel/python-dev)
       else
-
         ifneq ($(feature-libpython-version), 1)
           $(warning Python 3 is not yet supported; please set)
           $(warning PYTHON and/or PYTHON_CONFIG appropriately.)

tools/perf/builtin-stat.c

@@ -312,8 +312,12 @@ static int read_counter(struct perf_evsel *counter)
 			struct perf_counts_values *count;
 
 			count = perf_counts(counter->counts, cpu, thread);
-			if (perf_evsel__read(counter, cpu, thread, count))
+			if (perf_evsel__read(counter, cpu, thread, count)) {
+				counter->counts->scaled = -1;
+				perf_counts(counter->counts, cpu, thread)->ena = 0;
+				perf_counts(counter->counts, cpu, thread)->run = 0;
 				return -1;
+			}
 
 			if (STAT_RECORD) {
 				if (perf_evsel__write_stat_event(counter, cpu, thread, count)) {
@@ -338,12 +342,14 @@ static int read_counter(struct perf_evsel *counter)
 static void read_counters(void)
 {
 	struct perf_evsel *counter;
+	int ret;
 
 	evlist__for_each_entry(evsel_list, counter) {
-		if (read_counter(counter))
+		ret = read_counter(counter);
+		if (ret)
 			pr_debug("failed to read counter %s\n", counter->name);
 
-		if (perf_stat_process_counter(&stat_config, counter))
+		if (ret == 0 && perf_stat_process_counter(&stat_config, counter))
 			pr_warning("failed to process counter %s\n", counter->name);
 	}
 }

tools/perf/util/event.c

@@ -1,5 +1,5 @@
 #include <linux/types.h>
-#include <linux/mman.h> /* To get things like MAP_HUGETLB even on older libc headers */
+#include <uapi/linux/mman.h> /* To get things like MAP_HUGETLB even on older libc headers */
 #include <api/fs/fs.h>
 #include "event.h"
 #include "debug.h"

tools/perf/util/evsel.c

@@ -1239,7 +1239,7 @@ int perf_evsel__read(struct perf_evsel *evsel, int cpu, int thread,
 	if (FD(evsel, cpu, thread) < 0)
 		return -EINVAL;
 
-	if (readn(FD(evsel, cpu, thread), count, sizeof(*count)) < 0)
+	if (readn(FD(evsel, cpu, thread), count, sizeof(*count)) <= 0)
 		return -errno;
 
 	return 0;
@@ -1257,7 +1257,7 @@ int __perf_evsel__read_on_cpu(struct perf_evsel *evsel,
 	if (evsel->counts == NULL && perf_evsel__alloc_counts(evsel, cpu + 1, thread + 1) < 0)
 		return -ENOMEM;
 
-	if (readn(FD(evsel, cpu, thread), &count, nv * sizeof(u64)) < 0)
+	if (readn(FD(evsel, cpu, thread), &count, nv * sizeof(u64)) <= 0)
 		return -errno;
 
 	perf_evsel__compute_deltas(evsel, cpu, thread, &count);

tools/perf/util/util.c

@@ -696,7 +696,8 @@ const char *perf_tip(const char *dirpath)
 
 	tips = strlist__new("tips.txt", &conf);
 	if (tips == NULL)
-		return errno == ENOENT ? NULL : "Tip: get more memory! ;-p";
+		return errno == ENOENT ? NULL :
+			"Tip: check path of tips.txt or get more memory! ;-p";
 
 	if (strlist__nr_entries(tips) == 0)
 		goto out;