[GIT PULL 0/8] perf/core improvements and fixes

[GIT PULL 0/8] perf/core improvements and fixes

[Arnaldo Carvalho de Melo]

Hi Ingo,

	Please consider pulling,

- Arnaldo

The following changes since commit c36608843adf4674c462e49f63b64b2987d0ba0b:

  Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent (2016-01-13 10:36:03 +0100)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git tags/perf-core-for-mingo

for you to fetch changes up to 96b9e70b8e6cd65f71ee71889143976f3afb038a:

  perf build: Introduce FEATURES_DUMP make variable (2016-01-15 16:32:00 -0300)

----------------------------------------------------------------
perf tools improvements and fixes:

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>

----------------------------------------------------------------
Ben Hutchings (1):
      perf symbols: Fix reading of build-id from vDSO

Jiri Olsa (2):
      perf build: Add feature-dump target
      perf build: Introduce FEATURES_DUMP make variable

Ravi Bangoria (1):
      perf kvm record/report: 'unprocessable sample' error while recording/reporting guest data

Wang Nan (4):
      perf build: Set parallel making options build-test
      perf build: Pass O option to Makefile.perf in build-test
      perf build: Test correct path of perf in build-test
      perf build: Pass O option to kernel makefile in build-test

 tools/perf/Makefile.perf   | 25 ++++++++++++++++++++-
 tools/perf/config/Makefile |  4 ++++
 tools/perf/tests/make      | 55 +++++++++++++++++++++++++++++++++-------------
 tools/perf/util/session.c  |  2 +-
 tools/perf/util/symbol.c   |  2 +-
 5 files changed, 70 insertions(+), 18 deletions(-)

[PATCH 1/8] perf kvm record/report: 'unprocessable sample' error while recording/reporting guest data

[Arnaldo Carvalho de Melo]

From: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>

While recording guest samples in host using perf kvm record, it will
populate unprocessable sample error, though samples will be recorded
properly. While generating report using perf kvm report, no samples will
be processed and same error will populate. We have seen this behaviour
with upstream perf(4.4-rc3) on x86 and ppc64 hardware.

Reason behind this failure is, when it tries to fetch machine from
rb_tree of machines, it fails. As a part of tracing a bug, we figured
out that this code was incorrectly refactored in commit 54245fdc3576
("perf session: Remove wrappers to machines__find").

This patch will change the functionality such that if it can't fetch
machine in first trial, it will create one node of machine and add that to
rb_tree. So next time when it tries to fetch same machine from rb_tree,
it won't fail. Actually it was the case before refactoring of code in
aforementioned commit.

This patch is generated from acme perf/core branch.

Below I've mention an example that demonstrate the behaviour before and
after applying patch.

Before applying patch:
[Note: One needs to run guest before recording data in host]

  ravi@ravi-bangoria:~$ ./perf kvm record -a
  Warning:
  5903 unprocessable samples recorded.
  Do you have a KVM guest running and not using 'perf kvm'?
  [ perf record: Captured and wrote 1.409 MB perf.data.guest (285 samples) ]

  ravi@ravi-bangoria:~$ ./perf kvm report --stdio
  Warning:
  5903 unprocessable samples recorded.
  Do you have a KVM guest running and not using 'perf kvm'?
  # To display the perf.data header info, please use --header/--header-only options.
  #
  # Total Lost Samples: 0
  #
  # Samples: 285  of event 'cycles'
  # Event count (approx.): 88715406
  #
  # Overhead  Command  Shared Object  Symbol
  # ........  .......  .............  ......
  #

  # (For a higher level overview, try: perf report --sort comm,dso)
  #

After applying patch:

  ravi@ravi-bangoria:~$ ./perf kvm record -a
  [ perf record: Captured and wrote 1.188 MB perf.data.guest (17 samples) ]

  ravi@ravi-bangoria:~$ ./perf kvm report --stdio
  # To display the perf.data header info, please use --header/--header-only options.
  #
  # Total Lost Samples: 0
  #
  # Samples: 17  of event 'cycles'
  # Event count (approx.): 700746
  #
  # Overhead  Command  Shared Object     Symbol
  # ........  .......  ................  ......................
  #
      34.19%  :5758    [unknown]         [g] 0xffffffff818682ab
      22.79%  :5758    [unknown]         [g] 0xffffffff812dc7f8
      22.79%  :5758    [unknown]         [g] 0xffffffff818650d0
      14.83%  :5758    [unknown]         [g] 0xffffffff8161a1b6
       2.49%  :5758    [unknown]         [g] 0xffffffff818692bf
       0.48%  :5758    [unknown]         [g] 0xffffffff81869253
       0.05%  :5758    [unknown]         [g] 0xffffffff81869250

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # v3.19+
Fixes: 54245fdc3576 ("perf session: Remove wrappers to machines__find")
Link: http://lkml.kernel.org/r/1449471302-11283-1-git-send-email-ravi.bangoria@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/session.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index d5636ba94b20..40b7a0d0905b 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -1149,7 +1149,7 @@ static struct machine *machines__find_for_cpumode(struct machines *machines,
 
 		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;
 	}
 
-- 
2.1.0

[PATCH 2/8] perf symbols: Fix reading of build-id from vDSO

[Arnaldo Carvalho de Melo]

From: Ben Hutchings <ben@decadent.org.uk>

We need to use the long name (the filename) when reading the build-id
from a DSO.  Using the short name doesn't work for (at least) vDSOs.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160113172301.GT28542@decadent.org.uk
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/symbol.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 3b2de6eb3376..ab02209a7cf3 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1466,7 +1466,7 @@ int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
 	 * 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);
 
 	/*
-- 
2.1.0

[PATCH 3/8] perf build: Set parallel making options build-test

[Arnaldo Carvalho de Melo]

From: Wang Nan <wangnan0@huawei.com>

'make build-test' is painful because of time consuming. In a full test,
all test cases are built twice with tools/perf/Makefile and
tools/perf/Makefile.perf. 'Makefile' automatically computes parallel
options for make, but 'Makefile.perf' not, so all test cases is built
with one job. It is very slow.

This patch adds '-j' options to Makefile.perf testing. It computes
parallel building options like what tools/perf/Makefile does, and pass
'-j' option to Makefile.perf test.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1452687442-6186-2-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/tests/make | 23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/tools/perf/tests/make b/tools/perf/tests/make
index df38decc48c3..c0ee67906e0a 100644
--- a/tools/perf/tests/make
+++ b/tools/perf/tests/make
@@ -5,7 +5,7 @@ ifeq ($(MAKECMDGOALS),)
 # 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
 else
 # run only specific test over 'Makefile'
 %:
@@ -14,6 +14,15 @@ endif
 else
 PERF := .
 
+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
 LC_COLLATE=C
@@ -252,7 +261,7 @@ clean := @(cd $(PERF); make -s -f $(MK) 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) DESTDIR=$$TMP_DEST $($@)"; \
 	echo "- $@: $$cmd" && echo $$cmd > $@ && \
 	( eval $$cmd ) >> $@ 2>&1; \
 	echo "  test: $(call test,$@)" >> $@ 2>&1; \
@@ -263,7 +272,7 @@ $(run_O):
 	$(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; \
@@ -277,15 +286,15 @@ tarpkg:
 	rm -f $@
 
 make_kernelsrc:
-	@echo "- make -C <kernelsrc> tools/perf"
+	@echo "- make -C <kernelsrc> $(PARALLEL_OPT) tools/perf"
 	$(call clean); \
-	(make -C ../.. tools/perf) > $@ 2>&1 && \
+	(make -C ../.. $(PARALLEL_OPT) tools/perf) > $@ 2>&1 && \
 	test -x perf && rm -f $@ || (cat $@ ; false)
 
 make_kernelsrc_tools:
-	@echo "- make -C <kernelsrc>/tools perf"
+	@echo "- make -C <kernelsrc>/tools $(PARALLEL_OPT) perf"
 	$(call clean); \
-	(make -C ../../tools perf) > $@ 2>&1 && \
+	(make -C ../../tools $(PARALLEL_OPT) perf) > $@ 2>&1 && \
 	test -x perf && rm -f $@ || (cat $@ ; false)
 
 all: $(run) $(run_O) tarpkg make_kernelsrc make_kernelsrc_tools
-- 
2.1.0

[PATCH 4/8] perf build: Pass O option to Makefile.perf in build-test

[Arnaldo Carvalho de Melo]

From: Wang Nan <wangnan0@huawei.com>

Unlike tools/perf/Makefile, tools/perf/Makefile.perf obey 'O' option
when it is passed through cmdline only, due to code in
tools/scripts/Makefile.include:

 ifneq ($(O),)
 ifeq ($(origin O), command line)
 	...
 	ABSOLUTE_O := $(shell cd $(O) ; pwd)
 	OUTPUT := $(ABSOLUTE_O)/$(if $(subdir),$(subdir)/)
 endif
 endif

This patch passes 'O' to Makefile.perf through cmdline explicitly
to make it follow O variable during build-test.

'make clean' should have identical 'O' option with 'make'. If not,
config-clean may error.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1452830421-77757-3-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/tests/make | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/tools/perf/tests/make b/tools/perf/tests/make
index c0ee67906e0a..fc2a9a31113f 100644
--- a/tools/perf/tests/make
+++ b/tools/perf/tests/make
@@ -5,7 +5,7 @@ ifeq ($(MAKECMDGOALS),)
 # 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 SET_PARALLEL=1
+	@echo "Testing Makefile.perf"; $(MAKE) -sf tests/make MK=Makefile.perf SET_PARALLEL=1 SET_O=1
 else
 # run only specific test over 'Makefile'
 %:
@@ -13,6 +13,14 @@ else
 endif
 else
 PERF := .
+O_OPT :=
+
+ifneq ($(O),)
+  FULL_O := $(shell readlink -f $(O) || echo $(O))
+  ifeq ($(SET_O),1)
+    O_OPT := 'O=$(FULL_O)'
+  endif
+endif
 
 PARALLEL_OPT=
 ifeq ($(SET_PARALLEL),1)
@@ -256,12 +264,12 @@ endif
 
 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=$$(mktemp -d); \
-	cmd="cd $(PERF) && make -f $(MK) $(PARALLEL_OPT) DESTDIR=$$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; \
-- 
2.1.0

[PATCH 5/8] perf build: Test correct path of perf in build-test

[Arnaldo Carvalho de Melo]

From: Wang Nan <wangnan0@huawei.com>

If an 'O' is passed to 'make build-test', many 'test -x' and 'test -f'
will fail because perf resides in a different directory. Fix this by
computing PERF_OUT according to 'O' and test correct output files.
For make_kernelsrc and make_kernelsrc_tools, set KBUILD_OUTPUT_DIR
instead because the path is different from others ($(O)/perf vs
 $(O)/tools/perf).

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1452830421-77757-4-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/tests/make | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/tools/perf/tests/make b/tools/perf/tests/make
index fc2a9a31113f..29810cf2c117 100644
--- a/tools/perf/tests/make
+++ b/tools/perf/tests/make
@@ -13,10 +13,12 @@ else
 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
@@ -173,11 +175,11 @@ test_make_doc    := $(test_ok)
 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				\
@@ -244,7 +246,7 @@ test_make_perf_o_O            := test -f $$TMP_O/perf.o
 test_make_util_map_o_O        := test -f $$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 $$TMP_O/perf
@@ -293,17 +295,22 @@ tarpkg:
 	( eval $$cmd ) >> $@ 2>&1 && \
 	rm -f $@
 
+KERNEL_O := ../..
+ifneq ($(O),)
+  KERNEL_O := $(O)
+endif
+
 make_kernelsrc:
 	@echo "- make -C <kernelsrc> $(PARALLEL_OPT) tools/perf"
 	$(call clean); \
 	(make -C ../.. $(PARALLEL_OPT) tools/perf) > $@ 2>&1 && \
-	test -x perf && rm -f $@ || (cat $@ ; false)
+	test -x $(KERNEL_O)/tools/perf/perf && rm -f $@ || (cat $@ ; false)
 
 make_kernelsrc_tools:
 	@echo "- make -C <kernelsrc>/tools $(PARALLEL_OPT) perf"
 	$(call clean); \
 	(make -C ../../tools $(PARALLEL_OPT) perf) > $@ 2>&1 && \
-	test -x perf && rm -f $@ || (cat $@ ; false)
+	test -x $(KERNEL_O)/tools/perf/perf && rm -f $@ || (cat $@ ; false)
 
 all: $(run) $(run_O) tarpkg make_kernelsrc make_kernelsrc_tools
 	@echo OK
-- 
2.1.0

[PATCH 6/8] perf build: Pass O option to kernel makefile in build-test

[Arnaldo Carvalho de Melo]

From: Wang Nan <wangnan0@huawei.com>

Kernel makefile only follows an 'O' option passed from command line
explicitely. In build-test with 'O' option set, kernel makefile
contaminate kernel source directory. Build test also fail if we don't
create output directory manually.

K_O_OPT is added and passed to kernel makefile if 'O' is passed
to build-test.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1452830421-77757-5-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/tests/make | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/tools/perf/tests/make b/tools/perf/tests/make
index 29810cf2c117..f918015512af 100644
--- a/tools/perf/tests/make
+++ b/tools/perf/tests/make
@@ -22,6 +22,7 @@ ifneq ($(O),)
   ifeq ($(SET_O),1)
     O_OPT := 'O=$(FULL_O)'
   endif
+  K_O_OPT := 'O=$(FULL_O)'
 endif
 
 PARALLEL_OPT=
@@ -301,15 +302,15 @@ ifneq ($(O),)
 endif
 
 make_kernelsrc:
-	@echo "- make -C <kernelsrc> $(PARALLEL_OPT) tools/perf"
+	@echo "- make -C <kernelsrc> $(PARALLEL_OPT) $(K_O_OPT) tools/perf"
 	$(call clean); \
-	(make -C ../.. $(PARALLEL_OPT) tools/perf) > $@ 2>&1 && \
+	(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 $(PARALLEL_OPT) perf"
+	@echo "- make -C <kernelsrc>/tools $(PARALLEL_OPT) $(K_O_OPT) perf"
 	$(call clean); \
-	(make -C ../../tools $(PARALLEL_OPT) perf) > $@ 2>&1 && \
+	(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
-- 
2.1.0

[PATCH 7/8] perf build: Add feature-dump target

[Arnaldo Carvalho de Melo]

From: Jiri Olsa <jolsa@kernel.org>

To provide FEATURE-DUMP into $(FEATURE_DUMP_COPY) if defined, with no
further action.

Get feature dump of the current build:
  $ make feature-dump
    BUILD:   Doing 'make -j4' parallel build

  Auto-detecting system features:
  ...                         dwarf: [ on  ]

  FEATURE-DUMP file available in FEATURE-DUMP

Get feature dump static build into /tmp/fd file:

  $ make feature-dump FEATURE_DUMP_COPY=/tmp/fd LDFLAGS=-static
    BUILD:   Doing 'make -j4' parallel build

  Auto-detecting system features:
  ...                         dwarf: [ OFF ]

  SNIP

  FEATURE-DUMP file copied into /tmp/fd

Suggested-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1452830421-77757-6-git-send-email-wangnan0@huawei.com
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/Makefile.perf | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 0a22407e1d7d..f758a72df1b3 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -611,6 +611,17 @@ clean: $(LIBTRACEEVENT)-clean $(LIBAPI)-clean $(LIBBPF)-clean $(LIBSUBCMD)-clean
 	$(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:
 #
-- 
2.1.0

[PATCH 8/8] perf build: Introduce FEATURES_DUMP make variable

[Arnaldo Carvalho de Melo]

From: Jiri Olsa <jolsa@kernel.org>

Introducing FEATURES_DUMP make variable to provide features
detection dump file and bypass the feature detection.

The intention is to use this during build tests to skip
repeated features detection, like:

Get feature dump static build into /tmp/fd file:
  $ make feature-dump FEATURE_DUMP_COPY=/tmp/fd LDFLAGS=-static
    BUILD:   Doing 'make -j4' parallel build

  Auto-detecting system features:
  ...                         dwarf: [ OFF ]

  SNIP

  FEATURE-DUMP file copied into /tmp/fd

Use /tmp/fd to build perf:
  $ make FEATURES_DUMP=/tmp/fd LDFLAGS=-static

  $ file perf
  perf: ELF 64-bit LSB executable, x86-64, version 1 (GNU/Linux), statically linked, for ...

Suggested-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1452830421-77757-7-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/Makefile.perf   | 14 +++++++++++++-
 tools/perf/config/Makefile |  4 ++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index f758a72df1b3..5d34815c7ccb 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -77,6 +77,9 @@ include config/utilities.mak
 # 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 @@ ifeq ($(config),1)
 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 @@ $(LIBAPI)-clean:
 	$(Q)$(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)
diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile
index e5959c136a19..511141b102e8 100644
--- a/tools/perf/config/Makefile
+++ b/tools/perf/config/Makefile
@@ -181,7 +181,11 @@ LDFLAGS += -Wl,-z,noexecstack
 
 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
-- 
2.1.0

Re: [GIT PULL 0/8] perf/core improvements and fixes

[Ingo Molnar]

* Arnaldo Carvalho de Melo <acme@kernel.org> wrote:

> Hi Ingo,
> 
> 	Please consider pulling,
> 
> - Arnaldo
> 
> The following changes since commit c36608843adf4674c462e49f63b64b2987d0ba0b:
> 
>   Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent (2016-01-13 10:36:03 +0100)
> 
> are available in the git repository at:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git tags/perf-core-for-mingo
> 
> for you to fetch changes up to 96b9e70b8e6cd65f71ee71889143976f3afb038a:
> 
>   perf build: Introduce FEATURES_DUMP make variable (2016-01-15 16:32:00 -0300)
> 
> ----------------------------------------------------------------
> perf tools improvements and fixes:
> 
> 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>
> 
> ----------------------------------------------------------------
> Ben Hutchings (1):
>       perf symbols: Fix reading of build-id from vDSO
> 
> Jiri Olsa (2):
>       perf build: Add feature-dump target
>       perf build: Introduce FEATURES_DUMP make variable
> 
> Ravi Bangoria (1):
>       perf kvm record/report: 'unprocessable sample' error while recording/reporting guest data
> 
> Wang Nan (4):
>       perf build: Set parallel making options build-test
>       perf build: Pass O option to Makefile.perf in build-test
>       perf build: Test correct path of perf in build-test
>       perf build: Pass O option to kernel makefile in build-test
> 
>  tools/perf/Makefile.perf   | 25 ++++++++++++++++++++-
>  tools/perf/config/Makefile |  4 ++++
>  tools/perf/tests/make      | 55 +++++++++++++++++++++++++++++++++-------------
>  tools/perf/util/session.c  |  2 +-
>  tools/perf/util/symbol.c   |  2 +-
>  5 files changed, 70 insertions(+), 18 deletions(-)

Pulled, thanks a lot Arnaldo!

	Ingo