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

Pull perf tools improvements and fixes from Arnaldo Carvalho de Melo:

User visible bug fixes:

  - Fix reading of build-id from vDSO (Ben Hutchings)

  - Fix processing samples for guests, noticed with 'perf kvm',
    but noticeable as well via other tools, such as 'perf top'
    (Ravi Bangoria)

Build infrastructure:

  - Add feature-dump target and FEATURES_DUMP make variable, to
    allow reusing the feature detection results among multiple
    tools/ living codebases, such as perf and lib/bpf (Jiri Olsa)

  - 'make -C tools/perf build-test' improvements, making it more
    paralelizable and allowing building it outside of the source
    tree, using O= (Wang Nan)

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 0a22407..5d34815 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -77,6 +77,9 @@
 # Define NO_AUXTRACE if you do not want AUX area tracing support
 #
 # Define NO_LIBBPF if you do not want BPF support
+#
+# Define FEATURES_DUMP to provide features detection dump file
+# and bypass the feature detection
 
 # As per kernel Makefile, avoid funny character set dependencies
 unexport LC_ALL
@@ -166,6 +169,15 @@
 include config/Makefile
 endif
 
+# The FEATURE_DUMP_EXPORT holds location of the actual
+# FEATURE_DUMP file to be used to bypass feature detection
+# (for bpf or any other subproject)
+ifeq ($(FEATURES_DUMP),)
+FEATURE_DUMP_EXPORT := $(realpath $(OUTPUT)FEATURE-DUMP)
+else
+FEATURE_DUMP_EXPORT := $(FEATURES_DUMP)
+endif
+
 export prefix bindir sharedir sysconfdir DESTDIR
 
 # sparse is architecture-neutral, which means that we need to tell it
@@ -436,7 +448,7 @@
 	$(Q)$(MAKE) -C $(LIB_DIR) O=$(OUTPUT) clean >/dev/null
 
 $(LIBBPF): fixdep FORCE
-	$(Q)$(MAKE) -C $(BPF_DIR) O=$(OUTPUT) $(OUTPUT)libbpf.a FEATURES_DUMP=$(realpath $(OUTPUT)FEATURE-DUMP)
+	$(Q)$(MAKE) -C $(BPF_DIR) O=$(OUTPUT) $(OUTPUT)libbpf.a FEATURES_DUMP=$(FEATURE_DUMP_EXPORT)
 
 $(LIBBPF)-clean:
 	$(call QUIET_CLEAN, libbpf)
@@ -611,6 +623,17 @@
 	$(python-clean)
 
 #
+# To provide FEATURE-DUMP into $(FEATURE_DUMP_COPY)
+# file if defined, with no further action.
+feature-dump:
+ifdef FEATURE_DUMP_COPY
+	@cp $(OUTPUT)FEATURE-DUMP $(FEATURE_DUMP_COPY)
+	@echo "FEATURE-DUMP file copied into $(FEATURE_DUMP_COPY)"
+else
+	@echo "FEATURE-DUMP file available in $(OUTPUT)FEATURE-DUMP"
+endif
+
+#
 # Trick: if ../../.git does not exist - we are building out of tree for example,
 # then force version regeneration:
 #
diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile
index e5959c1..511141b 100644
--- a/tools/perf/config/Makefile
+++ b/tools/perf/config/Makefile
@@ -181,7 +181,11 @@
 
 EXTLIBS = -lpthread -lrt -lm -ldl
 
+ifeq ($(FEATURES_DUMP),)
 include $(srctree)/tools/build/Makefile.feature
+else
+include $(FEATURES_DUMP)
+endif
 
 ifeq ($(feature-stackprotector-all), 1)
   CFLAGS += -fstack-protector-all
diff --git a/tools/perf/tests/make b/tools/perf/tests/make
index df38dec..f918015 100644
--- a/tools/perf/tests/make
+++ b/tools/perf/tests/make
@@ -5,7 +5,7 @@
 # no target specified, trigger the whole suite
 all:
 	@echo "Testing Makefile";      $(MAKE) -sf tests/make MK=Makefile
-	@echo "Testing Makefile.perf"; $(MAKE) -sf tests/make MK=Makefile.perf
+	@echo "Testing Makefile.perf"; $(MAKE) -sf tests/make MK=Makefile.perf SET_PARALLEL=1 SET_O=1
 else
 # run only specific test over 'Makefile'
 %:
@@ -13,6 +13,26 @@
 endif
 else
 PERF := .
+PERF_O := $(PERF)
+O_OPT :=
+
+ifneq ($(O),)
+  FULL_O := $(shell readlink -f $(O) || echo $(O))
+  PERF_O := $(FULL_O)
+  ifeq ($(SET_O),1)
+    O_OPT := 'O=$(FULL_O)'
+  endif
+  K_O_OPT := 'O=$(FULL_O)'
+endif
+
+PARALLEL_OPT=
+ifeq ($(SET_PARALLEL),1)
+  cores := $(shell (getconf _NPROCESSORS_ONLN || egrep -c '^processor|^CPU[0-9]' /proc/cpuinfo) 2>/dev/null)
+  ifeq ($(cores),0)
+    cores := 1
+  endif
+  PARALLEL_OPT="-j$(cores)"
+endif
 
 # As per kernel Makefile, avoid funny character set dependencies
 unexport LC_ALL
@@ -156,11 +176,11 @@
 test_make_help_O := $(test_ok)
 test_make_doc_O  := $(test_ok)
 
-test_make_python_perf_so := test -f $(PERF)/python/perf.so
+test_make_python_perf_so := test -f $(PERF_O)/python/perf.so
 
-test_make_perf_o           := test -f $(PERF)/perf.o
-test_make_util_map_o       := test -f $(PERF)/util/map.o
-test_make_util_pmu_bison_o := test -f $(PERF)/util/pmu-bison.o
+test_make_perf_o           := test -f $(PERF_O)/perf.o
+test_make_util_map_o       := test -f $(PERF_O)/util/map.o
+test_make_util_pmu_bison_o := test -f $(PERF_O)/util/pmu-bison.o
 
 define test_dest_files
   for file in $(1); do				\
@@ -227,7 +247,7 @@
 test_make_util_map_o_O        := test -f $$TMP_O/util/map.o
 test_make_util_pmu_bison_o_O := test -f $$TMP_O/util/pmu-bison.o
 
-test_default = test -x $(PERF)/perf
+test_default = test -x $(PERF_O)/perf
 test = $(if $(test_$1),$(test_$1),$(test_default))
 
 test_default_O = test -x $$TMP_O/perf
@@ -247,12 +267,12 @@
 
 MAKEFLAGS := --no-print-directory
 
-clean := @(cd $(PERF); make -s -f $(MK) clean >/dev/null)
+clean := @(cd $(PERF); make -s -f $(MK) $(O_OPT) clean >/dev/null)
 
 $(run):
 	$(call clean)
 	@TMP_DEST=$$(mktemp -d); \
-	cmd="cd $(PERF) && make -f $(MK) DESTDIR=$$TMP_DEST $($@)"; \
+	cmd="cd $(PERF) && make -f $(MK) $(PARALLEL_OPT) $(O_OPT) DESTDIR=$$TMP_DEST $($@)"; \
 	echo "- $@: $$cmd" && echo $$cmd > $@ && \
 	( eval $$cmd ) >> $@ 2>&1; \
 	echo "  test: $(call test,$@)" >> $@ 2>&1; \
@@ -263,7 +283,7 @@
 	$(call clean)
 	@TMP_O=$$(mktemp -d); \
 	TMP_DEST=$$(mktemp -d); \
-	cmd="cd $(PERF) && make -f $(MK) O=$$TMP_O DESTDIR=$$TMP_DEST $($(patsubst %_O,%,$@))"; \
+	cmd="cd $(PERF) && make -f $(MK) $(PARALLEL_OPT) O=$$TMP_O DESTDIR=$$TMP_DEST $($(patsubst %_O,%,$@))"; \
 	echo "- $@: $$cmd" && echo $$cmd > $@ && \
 	( eval $$cmd ) >> $@ 2>&1 && \
 	echo "  test: $(call test_O,$@)" >> $@ 2>&1; \
@@ -276,17 +296,22 @@
 	( eval $$cmd ) >> $@ 2>&1 && \
 	rm -f $@
 
+KERNEL_O := ../..
+ifneq ($(O),)
+  KERNEL_O := $(O)
+endif
+
 make_kernelsrc:
-	@echo "- make -C <kernelsrc> tools/perf"
+	@echo "- make -C <kernelsrc> $(PARALLEL_OPT) $(K_O_OPT) tools/perf"
 	$(call clean); \
-	(make -C ../.. tools/perf) > $@ 2>&1 && \
-	test -x perf && rm -f $@ || (cat $@ ; false)
+	(make -C ../.. $(PARALLEL_OPT) $(K_O_OPT) tools/perf) > $@ 2>&1 && \
+	test -x $(KERNEL_O)/tools/perf/perf && rm -f $@ || (cat $@ ; false)
 
 make_kernelsrc_tools:
-	@echo "- make -C <kernelsrc>/tools perf"
+	@echo "- make -C <kernelsrc>/tools $(PARALLEL_OPT) $(K_O_OPT) perf"
 	$(call clean); \
-	(make -C ../../tools perf) > $@ 2>&1 && \
-	test -x perf && rm -f $@ || (cat $@ ; false)
+	(make -C ../../tools $(PARALLEL_OPT) $(K_O_OPT) perf) > $@ 2>&1 && \
+	test -x $(KERNEL_O)/tools/perf/perf && rm -f $@ || (cat $@ ; false)
 
 all: $(run) $(run_O) tarpkg make_kernelsrc make_kernelsrc_tools
 	@echo OK
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index d5636ba..40b7a0d 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -1149,7 +1149,7 @@
 
 		machine = machines__find(machines, pid);
 		if (!machine)
-			machine = machines__find(machines, DEFAULT_GUEST_KERNEL_ID);
+			machine = machines__findnew(machines, DEFAULT_GUEST_KERNEL_ID);
 		return machine;
 	}
 
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 3b2de6e..ab02209 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1466,7 +1466,7 @@
 	 * Read the build id if possible. This is required for
 	 * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work
 	 */
-	if (filename__read_build_id(dso->name, build_id, BUILD_ID_SIZE) > 0)
+	if (filename__read_build_id(dso->long_name, build_id, BUILD_ID_SIZE) > 0)
 		dso__set_build_id(dso, build_id);
 
 	/*