perf build: Pretend scandirat is missing with msan

Memory sanitizer lacks an interceptor for scandirat, reporting all
memory it allocates as uninitialized. Memory sanitizer has a scandir
interceptor

perf build: Pretend scandirat is missing with msan

Memory sanitizer lacks an interceptor for scandirat, reporting all
memory it allocates as uninitialized. Memory sanitizer has a scandir
interceptor so use the fallback function in this case. This allows
'perf test' to run under memory sanitizer.

Additional notes from Ian on running in this mode:

Note, as msan needs to instrument memory allocations libraries need to
be compiled with it. I lacked the msan built libraries and so built
with:
```
$ make -C tools/perf O=/tmp/perf DEBUG=1 EXTRA_CFLAGS="-O0 -g
-fno-omit-frame-pointer -fsanitize=memory
-fsanitize-memory-track-origins" CC=clang CXX=clang++ HOSTCC=clang
NO_LIBTRACEEVENT=1 NO_LIBELF=1 BUILD_BPF_SKEL=0 NO_LIBPFM=1
```
oh, I disabled libbpf here as the bpf system call also lacks msan interceptors.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240320163244.1287780-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

perf build: Add LIBTRACEEVENT_DIR build option

Currently, when libtraceevent is not linked,
perf does not support tracepoint:

# ./perf record -e sched:sched_switch -a sleep 10
event syntax erro

perf build: Add LIBTRACEEVENT_DIR build option

Currently, when libtraceevent is not linked,
perf does not support tracepoint:

# ./perf record -e sched:sched_switch -a sleep 10
event syntax error: 'sched:sched_switch'
\___ unsupported tracepoint

libtraceevent is necessary for tracepoint support
Run 'perf list' for a list of valid events

Usage: perf record [<options>] [<command>]
or: perf record [<options>] -- <command> [<options>]

-e, --event <event> event selector. use 'perf list' to list available events

For cross-compilation scenario, library may not be installed in the default
system path. Based on the above requirements, add LIBTRACEEVENT_DIR build
option to support specifying path of libtraceevent.

Example:

1. Cross compile libtraceevent
# cd /opt/libtraceevent
# CROSS_COMPILE=aarch64-linux-gnu- make

2. Cross compile perf
# cd tool/perf
# make VF=1 ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- NO_LIBELF=1 LDFLAGS=--static LIBTRACEEVENT_DIR=/opt/libtraceevent
<SNIP>
Auto-detecting system features:
<SNIP>
... LIBTRACEEVENT_DIR: /opt/libtraceevent

Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Yang Jihong <yangjihong@bytedance.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240314063000.2139877-1-yangjihong@bytedance.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

treewide: remove meaningless assignments in Makefiles

In Makefiles, $(error ), $(warning ), and $(info ) expand to the empty
string, as explained in the GNU Make manual [1]:
"The result of the expa

treewide: remove meaningless assignments in Makefiles

In Makefiles, $(error ), $(warning ), and $(info ) expand to the empty
string, as explained in the GNU Make manual [1]:
"The result of the expansion of this function is the empty string."

Therefore, they are no-op except for logging purposes.

$(shell ...) expands to the output of the command. It expands to the
empty string when the command does not print anything to stdout.
Hence, $(shell mkdir ...) is no-op except for creating the directory.

Remove meaningless assignments.

[1]: https://www.gnu.org/software/make/manual/make.html#Make-Control-Functions

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20240221134201.2656908-1-masahiroy@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-kbuild@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-perf-users@vger.kernel.org

show more ...

perf: build: introduce the libcapstone

Later we will use libcapstone to disassemble instructions of samples.

Signed-off-by: Changbin Du <changbin.du@huawei.com>
Reviewed-by: Adrian Hunter <adrian.h

perf: build: introduce the libcapstone

Later we will use libcapstone to disassemble instructions of samples.

Signed-off-by: Changbin Du <changbin.du@huawei.com>
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: changbin.du@gmail.com
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240217074046.4100789-2-changbin.du@huawei.com

show more ...

perf build: Cleanup perf register configuration

The target is to allow the tool to always enable the perf register
feature for native parsing and cross parsing, and current code doesn't
depend on th

perf build: Cleanup perf register configuration

The target is to allow the tool to always enable the perf register
feature for native parsing and cross parsing, and current code doesn't
depend on the macro 'HAVE_PERF_REGS_SUPPORT'.

This patch remove the variable 'NO_PERF_REGS' and the defined macro
'HAVE_PERF_REGS_SUPPORT' from the Makefile.

Signed-off-by: Leo Yan <leo.yan@linux.dev>
Reviewed-by: Ian Rogers <irogers@google.com>
Cc: James Clark <james.clark@arm.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Ming Wang <wangming01@loongson.cn>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: linux-csky@vger.kernel.org
Cc: linux-riscv@lists.infradead.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240214113947.240957-5-leo.yan@linux.dev

show more ...

perf build: Remove unused CONFIG_PERF_REGS

CONFIG_PERF_REGS is not used, remove it.

Signed-off-by: Leo Yan <leo.yan@linux.dev>
Reviewed-by: Ian Rogers <irogers@google.com>
Cc: James Clark <james.cl

perf build: Remove unused CONFIG_PERF_REGS

CONFIG_PERF_REGS is not used, remove it.

Signed-off-by: Leo Yan <leo.yan@linux.dev>
Reviewed-by: Ian Rogers <irogers@google.com>
Cc: James Clark <james.clark@arm.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Ming Wang <wangming01@loongson.cn>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: linux-csky@vger.kernel.org
Cc: linux-riscv@lists.infradead.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240214113947.240957-2-leo.yan@linux.dev

show more ...

perf build: Check whether pkg-config is installed when libtraceevent is linked

If pkg-config is not installed when libtraceevent is linked, the build fails.

The error information is as follows:

perf build: Check whether pkg-config is installed when libtraceevent is linked

If pkg-config is not installed when libtraceevent is linked, the build fails.

The error information is as follows:

$ make
<SNIP>
In file included from /home/yjh/projects_linux/perf-tool-next/linux/tools/perf/util/evsel.c:43:
/home/yjh/projects_linux/perf-tool-next/linux/tools/perf/util/trace-event.h:149:62: error: operator '&&' has no right operand
149 | #if defined(LIBTRACEEVENT_VERSION) && LIBTRACEEVENT_VERSION >= MAKE_LIBTRACEEVENT_VERSION(1, 5, 0)
| ^~
error: command '/usr/bin/gcc' failed with exit code 1
cp: cannot stat 'python_ext_build/lib/perf*.so': No such file or directory
make[2]: *** [Makefile.perf:668: python/perf.cpython-310-x86_64-linux-gnu.so] Error 1
make[2]: *** Waiting for unfinished jobs....

Because pkg-config is not installed, fail to get libtraceevent version in
Makefile.config file. As a result, LIBTRACEEVENT_VERSION is empty.
However, the preceding error information is not user-friendly.

Identify errors in advance by checking that pkg-config is installed at
compile time.

The build results of various scenarios are as follows:

1. build successful when libtraceevent is not linked and pkg-config is not installed

$ pkg-config --version
-bash: /usr/bin/pkg-config: No such file or directory
$ make clean >/dev/null
$ make NO_LIBTRACEEVENT=1 >/dev/null
Makefile.config:1133: No alternatives command found, you need to set JDIR= to point to the root of your Java directory
PERF_VERSION = 6.7.rc6.gd988c9f511af
$ echo $?
0

2. dummy pkg-config is missing when libtraceevent is linked

$ pkg-config --version
-bash: /usr/bin/pkg-config: No such file or directory
$ make clean >/dev/null
$ make >/dev/null
Makefile.config:221: *** Error: pkg-config needed by libtraceevent is missing on this system, please install it. Stop.
make[1]: *** [Makefile.perf:251: sub-make] Error 2
make: *** [Makefile:70: all] Error 2
$ echo $?
2

3. build successful when libtraceevent is linked and pkg-config is installed

$ pkg-config --version
0.29.2
$ make clean >/dev/null
$ make >/dev/null
Makefile.config:1133: No alternatives command found, you need to set JDIR= to point to the root of your Java directory
PERF_VERSION = 6.7.rc6.gd988c9f511af
$ echo $?
0

Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240112034019.3558584-1-yangjihong1@huawei.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

show more ...

perf probe: Convert to check dwarf_getcfi feature

Now it has a feature check for the dwarf_getcfi(), use it and convert
the code to check HAVE_DWARF_CFI_SUPPORT definition.

Suggested-by: Masami Hir

perf probe: Convert to check dwarf_getcfi feature

Now it has a feature check for the dwarf_getcfi(), use it and convert
the code to check HAVE_DWARF_CFI_SUPPORT definition.

Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: linux-toolchains@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Link: https://lore.kernel.org/r/20231110000012.3538610-10-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

perf build: Warn about missing libelf before warning about missing libbpf

As libelf is a requirement for libbpf if it is not available, as in some
container build tests where NO_LIBELF=1 is used, th

perf build: Warn about missing libelf before warning about missing libbpf

As libelf is a requirement for libbpf if it is not available, as in some
container build tests where NO_LIBELF=1 is used, then better warn about
the most basic library first.

Ditto for libz, check its availability before libbpf too.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/ZUEehyDk0FkPnvMR@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

perf build: Disable BPF skeletons if clang version is < 12.0.1

While building on a wide range of distros and clang versions it was
noticed that at least version 12.0.1 (noticed on Alpine 3.15 with
"

perf build: Disable BPF skeletons if clang version is < 12.0.1

While building on a wide range of distros and clang versions it was
noticed that at least version 12.0.1 (noticed on Alpine 3.15 with
"Alpine clang version 12.0.1") is needed to not fail with BTF generation
errors such as:

Debian:10

Debian clang version 11.0.1-2~deb10u1:

CLANG /tmp/build/perf/util/bpf_skel/.tmp/sample_filter.bpf.o
<SNIP>
GENSKEL /tmp/build/perf/util/bpf_skel/sample_filter.skel.h
libbpf: failed to find BTF for extern 'bpf_cast_to_kern_ctx' [21] section: -2
Error: failed to open BPF object file: No such file or directory
make[2]: *** [Makefile.perf:1121: /tmp/build/perf/util/bpf_skel/sample_filter.skel.h] Error 254
make[2]: *** Deleting file '/tmp/build/perf/util/bpf_skel/sample_filter.skel.h'

Amazon Linux 2:

clang version 11.1.0 (Amazon Linux 2 11.1.0-1.amzn2.0.2)

GENSKEL /tmp/build/perf/util/bpf_skel/sample_filter.skel.h
libbpf: elf: skipping unrecognized data section(18) .eh_frame
libbpf: elf: skipping relo section(19) .rel.eh_frame for section(18) .eh_frame
libbpf: failed to find BTF for extern 'bpf_cast_to_kern_ctx' [21] section: -2
Error: failed to open BPF object file: No such file or directory
make[2]: *** [/tmp/build/perf/util/bpf_skel/sample_filter.skel.h] Error 254
make[2]: *** Deleting file `/tmp/build/perf/util/bpf_skel/sample_filter.skel.h'

Ubuntu 20.04:

clang version 10.0.0-4ubuntu1

CLANG /tmp/build/perf/util/bpf_skel/.tmp/augmented_raw_syscalls.bpf.o
GENSKEL /tmp/build/perf/util/bpf_skel/bench_uprobe.skel.h
GENSKEL /tmp/build/perf/util/bpf_skel/bperf_leader.skel.h
libbpf: sec '.reluprobe': corrupted symbol #27 pointing to invalid section #65522 for relo #0
GENSKEL /tmp/build/perf/util/bpf_skel/bperf_follower.skel.h
Error: failed to open BPF object file: BPF object format invalid
make[2]: *** [Makefile.perf:1121: /tmp/build/perf/util/bpf_skel/bench_uprobe.skel.h] Error 95
make[2]: *** Deleting file '/tmp/build/perf/util/bpf_skel/bench_uprobe.skel.h'

So check if the version is at least 12.0.1 otherwise disable building
BPF skels and provide a message about it, continuing the build.

The message, when running on amazonlinux:2:

Makefile.config:698: Warning: Disabled BPF skeletons as reliable BTF generation needs at least clang version 12.0.1

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/ZTvGx/Ou6BVnYBqi@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

show more ...

perf build: Default BUILD_BPF_SKEL, warn/disable for missing deps

LIBBPF is dependent on zlib so move the NO_ZLIB and feature check
early to avoid statically building when zlib is disabled. This avo

perf build: Default BUILD_BPF_SKEL, warn/disable for missing deps

LIBBPF is dependent on zlib so move the NO_ZLIB and feature check
early to avoid statically building when zlib is disabled. This avoids
a linkage failure with perf and static libbpf when zlib isn't
specified.

Move BUILD_BPF_SKEL logic to one place and if not defined set
BUILD_BPF_SKEL to 1. Detect dependencies of building with BPF
skeletons and warn/disable if the dependencies aren't present.

Change Makefile.perf to contain BPF skeleton logic dependent on the
Makefile.config result and refresh the comment about BUILD_BPF_SKEL.

Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Namhyung Kim <namhyung@kernel.org>
Cc: James Clark <james.clark@arm.com>
Cc: Nick Terrell <terrelln@fb.com>
Cc: Patrice Duroux <patrice.duroux@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Tom Rix <trix@redhat.com>
Cc: llvm@lists.linux.dev
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230914211948.814999-3-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

show more ...

perf parse-events: Remove BPF event support

New features like the BPF --filter support in perf record have made the
BPF event functionality somewhat redundant. As shown by commit
fcb027c1a4f6 ("perf

perf parse-events: Remove BPF event support

New features like the BPF --filter support in perf record have made the
BPF event functionality somewhat redundant. As shown by commit
fcb027c1a4f6 ("perf tools: Revert enable indices setting syntax for BPF
map") and commit 14e4b9f4289a ("perf trace: Raw augmented syscalls fix
libbpf 1.0+ compatibility") the BPF event support hasn't been well
maintained and it adds considerable complexity in areas like event
parsing, not least as '/' is a separator for event modifiers as well as
in paths.

This patch removes support in the event parser for BPF events and then
the associated functions are removed. This leads to the removal of whole
source files like bpf-loader.c. Removing support means that augmented
syscalls in perf trace is broken, this will be fixed in a later commit
adding support using BPF skeletons.

The removal of BPF events causes an unused label warning from flex
generated code, so update build to ignore it:

```
util/parse-events-flex.c:2704:1: error: label ‘find_rule’ defined but not used [-Werror=unused-label]
2704 | find_rule: /* we branch to this label when backing up */
```

Committer notes:

Extracted from a larger patch that was also removing the support for
linking with libllvm and libclang, that were an alternative to using an
external clang execution to compile the .c event source code into BPF
bytecode.

Testing it:

# perf trace -e /home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.c
event syntax error: '/home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.c'
\___ Bad event or PMU

Unabled to find PMU or event on a PMU of 'home'

Initial error:
event syntax error: '/home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.c'
\___ Cannot find PMU `home'. Missing kernel support?
Run 'perf list' for a list of valid events

Usage: perf trace [<options>] [<command>]
or: perf trace [<options>] -- <command> [<options>]
or: perf trace record [<options>] [<command>]
or: perf trace record [<options>] -- <command> [<options>]

-e, --event <event> event/syscall selector. use 'perf list' to list available events
#

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Carsten Haitzler <carsten.haitzler@arm.com>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Fangrui Song <maskray@google.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Tom Rix <trix@redhat.com>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Wang ShaoBo <bobo.shaobowang@huawei.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: YueHaibing <yuehaibing@huawei.com>
Cc: bpf@vger.kernel.org
Cc: llvm@lists.linux.dev
Link: https://lore.kernel.org/r/20230810184853.2860737-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

perf bpf: Remove support for embedding clang for compiling BPF events (-e foo.c)

This never was in the default build for perf, is difficult to maintain
as it uses clang/llvm internals so ditch it, k

perf bpf: Remove support for embedding clang for compiling BPF events (-e foo.c)

This never was in the default build for perf, is difficult to maintain
as it uses clang/llvm internals so ditch it, keeping, for now, the
external compilation of .c BPF into .o bytecode and its subsequent
loading, that is also going to be removed, do it separately to help
bisection and to properly document what is being removed and why.

Committer notes:

Extracted from a larger patch and removed some leftovers, namely
deleting these now unused feature tests:

tools/build/feature/test-clang.cpp
tools/build/feature/test-cxx.cpp
tools/build/feature/test-llvm-version.cpp
tools/build/feature/test-llvm.cpp

Testing the use of BPF events after applying this patch:

To use the external clang/llvm toolchain to compile a .c event and then
use libbpf to load it, to get the syscalls:sys_enter_open* tracepoints
and read the filename pointer, putting it into the ring buffer right
after the usual tracepoint payload for 'perf trace' to then print it:

[root@quaco ~]# perf trace -e /home/acme/git/perf-tools-next/tools/perf/examples/bpf/augmented_raw_syscalls.c,open* --max-events=10
0.000 systemd-oomd/959 openat(dfd: CWD, filename: "/proc/meminfo", flags: RDONLY|CLOEXEC) = 12
0.083 abrt-dump-jour/1453 openat(dfd: CWD, filename: "/var/log/journal/d6a97235307247e09f13f326fb607e3c/system.journal", flags: RDONLY|CLOEXEC|NONBLOCK) = 4
0.063 abrt-dump-jour/1454 openat(dfd: CWD, filename: "/var/log/journal/d6a97235307247e09f13f326fb607e3c/system.journal", flags: RDONLY|CLOEXEC|NONBLOCK) = 4
0.082 abrt-dump-jour/1455 openat(dfd: CWD, filename: "/var/log/journal/d6a97235307247e09f13f326fb607e3c/system.journal", flags: RDONLY|CLOEXEC|NONBLOCK) = 4
250.124 systemd-oomd/959 openat(dfd: CWD, filename: "/proc/meminfo", flags: RDONLY|CLOEXEC) = 12
250.521 systemd-oomd/959 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/app.slice/memory.pressure", flags: RDONLY|CLOEXEC) = 12
251.047 systemd-oomd/959 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/app.slice/memory.current", flags: RDONLY|CLOEXEC) = 12
251.162 systemd-oomd/959 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/app.slice/memory.min", flags: RDONLY|CLOEXEC) = 12
251.242 systemd-oomd/959 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/app.slice/memory.low", flags: RDONLY|CLOEXEC) = 12
251.353 systemd-oomd/959 openat(dfd: CWD, filename: "/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service/app.slice/memory.swap.current", flags: RDONLY|CLOEXEC) = 12
[root@quaco ~]#

Same thing, but with a prebuilt .o BPF bytecode:

[root@quaco ~]# perf trace -e /home/acme/git/perf-tools-next/tools/perf/examples/bpf/augmented_raw_syscalls.o,open* --max-events=10
0.000 systemd-oomd/959 openat(dfd: CWD, filename: "/proc/meminfo", flags: RDONLY|CLOEXEC) = 12
0.083 abrt-dump-jour/1453 openat(dfd: CWD, filename: "/var/log/journal/d6a97235307247e09f13f326fb607e3c/system.journal", flags: RDONLY|CLOEXEC|NONBLOCK) = 4
0.083 abrt-dump-jour/1455 openat(dfd: CWD, filename: "/var/log/journal/d6a97235307247e09f13f326fb607e3c/system.journal", flags: RDONLY|CLOEXEC|NONBLOCK) = 4
0.062 abrt-dump-jour/1454 openat(dfd: CWD, filename: "/var/log/journal/d6a97235307247e09f13f326fb607e3c/system.journal", flags: RDONLY|CLOEXEC|NONBLOCK) = 4
249.985 systemd-oomd/959 openat(dfd: CWD, filename: "/proc/meminfo", flags: RDONLY|CLOEXEC) = 12
466.763 thermald/1234 openat(dfd: CWD, filename: "/sys/class/powercap/intel-rapl/intel-rapl:0/intel-rapl:0:2/energy_uj") = 13
467.145 thermald/1234 openat(dfd: CWD, filename: "/sys/class/powercap/intel-rapl/intel-rapl:0/energy_uj") = 13
467.311 thermald/1234 openat(dfd: CWD, filename: "/sys/class/thermal/thermal_zone2/temp") = 13
500.040 cgroupify/24006 openat(dfd: 4, filename: ".", flags: RDONLY|CLOEXEC|DIRECTORY|NONBLOCK) = 5
500.295 cgroupify/24006 openat(dfd: 4, filename: "24616/cgroup.procs") = 5
[root@quaco ~]#

Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Carsten Haitzler <carsten.haitzler@arm.com>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Fangrui Song <maskray@google.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Tom Rix <trix@redhat.com>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Wang ShaoBo <bobo.shaobowang@huawei.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/lkml/ZNZWsAXg2px1sm2h@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

perf build: Support llvm and clang support compiled in

Perf build suports llvm and clang support compiled in.
Test case 56 builtin clang support provides a test case
which is always skipped.

Link p

perf build: Support llvm and clang support compiled in

Perf build suports llvm and clang support compiled in.
Test case 56 builtin clang support provides a test case
which is always skipped.

Link perf with the latest llvm and clang libraries and
enable this test case.

Use 'make LIBCLANGLLVM=1' to include this support.

V2: Add Library patch before -lclang-cpp

Output before:

# ./perf test 56
56: builtin clang support :
56.1: builtin clang compile C source to IR : Skip (not compiled in)
56.2: builtin clang compile C source to ELF object: Skip (not compiled in)

Output after:

# ./perf test 56
56: builtin clang support :
56.1: builtin clang compile C source to IR : Ok
56.2: builtin clang compile C source to ELF object : Ok
#

From Ian Rogers:

Build tested with LLVM 14 and 15 using:
BUILD_BPF_SKEL=1 LIBCLANGLLVM=1 LLVM_CONFIG=llvm-config-14
BUILD_BPF_SKEL=1 LIBCLANGLLVM=1 LLVM_CONFIG=llvm-config-15

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Ian Rogers <irogers@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lore.kernel.org/r/20230725150347.3479291-2-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

perf build: Add Wextra for C++ compilation

Commit d58ac0bf8d1e ("perf build: Add clang and llvm compile and
linking support") added -Wall and -Wno-strict-aliasing for CXXFLAGS,
but not -Wextra. -Wno

perf build: Add Wextra for C++ compilation

Commit d58ac0bf8d1e ("perf build: Add clang and llvm compile and
linking support") added -Wall and -Wno-strict-aliasing for CXXFLAGS,
but not -Wextra. -Wno-strict-aliasing is no longer necessary, adding
-Wextra for CXXFLAGS requires adding -Wno-unused-parameter clang.cpp
and clang-test.cpp for LIBCLANGLLVM=1 to build.

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: James Clark <james.clark@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Gaosheng Cui <cuigaosheng1@huawei.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Tom Rix <trix@redhat.com>
Cc: bpf@vger.kernel.org
Cc: llvm@lists.linux.dev
Link: https://lore.kernel.org/r/20230728064917.767761-4-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

perf build: Don't always set -funwind-tables and -ggdb3

Commit 6a40cd90f5deb6de ("perf tools: Add libunwind dependency for DWARF
CFI unwinding") added libunwind support but also -funwind-tables and

perf build: Don't always set -funwind-tables and -ggdb3

Commit 6a40cd90f5deb6de ("perf tools: Add libunwind dependency for DWARF
CFI unwinding") added libunwind support but also -funwind-tables and
-ggdb3 to the standard build. These build flags aren't necessary so
remove, set -g when DEBUG is enabled for the build.

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: James Clark <james.clark@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Gaosheng Cui <cuigaosheng1@huawei.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Tom Rix <trix@redhat.com>
Cc: bpf@vger.kernel.org
Cc: llvm@lists.linux.dev
Link: https://lore.kernel.org/r/20230728064917.767761-3-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

perf build: Add LTO build option

Add an LTO build option, that sets the appropriate CFLAGS and CXXFLAGS
values.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel

perf build: Add LTO build option

Add an LTO build option, that sets the appropriate CFLAGS and CXXFLAGS
values.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Carsten Haitzler <carsten.haitzler@arm.com>
Cc: Fangrui Song <maskray@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Tom Rix <trix@redhat.com>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: bpf@vger.kernel.org
Cc: llvm@lists.linux.dev
Link: https://lore.kernel.org/r/20230724201247.748146-5-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

perf build: Fix library not found error when using CSLIBS

-L only specifies the search path for libraries directly provided in the
link line with -l. Because -lopencsd isn't specified, it's only lin

perf build: Fix library not found error when using CSLIBS

-L only specifies the search path for libraries directly provided in the
link line with -l. Because -lopencsd isn't specified, it's only linked
because it's a dependency of -lopencsd_c_api. Dependencies like this are
resolved using the default system search paths or -rpath-link=... rather
than -L. This means that compilation only works if OpenCSD is installed
to the system rather than provided with the CSLIBS (-L) option.

This could be fixed by adding -Wl,-rpath-link=$(CSLIBS) but that is less
conventional than just adding -lopencsd to the link line so that it uses
-L. -lopencsd seems to have been removed in commit ed17b1914978eddb
("perf tools: Drop requirement for libstdc++.so for libopencsd check")
because it was thought that there was a chance compilation would work
even if it didn't exist, but I think that only applies to libstdc++ so
there is no harm to add it back. libopencsd.so and libopencsd_c_api.so
would always exist together.

Testing
=======

The following scenarios now all work:

* Cross build with OpenCSD installed
* Cross build using CSLIBS=...
* Native build with OpenCSD installed
* Native build using CSLIBS=...
* Static cross build with OpenCSD installed
* Static cross build with CSLIBS=...

Committer testing:

⬢[acme@toolbox perf-tools]$ alias m
alias m='make -k BUILD_BPF_SKEL=1 CORESIGHT=1 O=/tmp/build/perf-tools -C tools/perf install-bin && git status && perf test python ; perf record -o /dev/null sleep 0.01 ; perf stat --null sleep 0.01'
⬢[acme@toolbox perf-tools]$ ldd ~/bin/perf | grep csd
libopencsd_c_api.so.1 => /lib64/libopencsd_c_api.so.1 (0x00007fd49c44e000)
libopencsd.so.1 => /lib64/libopencsd.so.1 (0x00007fd49bd56000)
⬢[acme@toolbox perf-tools]$ cat /etc/redhat-release
Fedora release 36 (Thirty Six)
⬢[acme@toolbox perf-tools]$

Fixes: ed17b1914978eddb ("perf tools: Drop requirement for libstdc++.so for libopencsd check")
Reported-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
Signed-off-by: James Clark <james.clark@arm.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Uwe Kleine-König <uwe@kleine-koenig.org>
Cc: coresight@lists.linaro.org
Closes: https://lore.kernel.org/linux-arm-kernel/56905d7a-a91e-883a-b707-9d5f686ba5f1@arm.com/
Link: https://lore.kernel.org/all/36cc4dc6-bf4b-1093-1c0a-876e368af183@kleine-koenig.org/
Link: https://lore.kernel.org/r/20230707154546.456720-1-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

perf test: Fix a compile error on pe-file-parsing.c

The dso__find_symbol_by_name() should be have idx pointer argument.
Found during the build-test.

$ make build-test
...
CC /tmp/tmp.6

perf test: Fix a compile error on pe-file-parsing.c

The dso__find_symbol_by_name() should be have idx pointer argument.
Found during the build-test.

$ make build-test
...
CC /tmp/tmp.6JwPK1xbWG/tests/pe-file-parsing.o
tests/pe-file-parsing.c: In function ‘run_dir’:
tests/pe-file-parsing.c:64:15: error: too few arguments to function ‘dso__find_symbol_by_name’
64 | sym = dso__find_symbol_by_name(dso, "main");
| ^~~~~~~~~~~~~~~~~~~~~~~~
In file included from tests/pe-file-parsing.c:16:
/usr/local/google/home/namhyung/project/linux/tools/perf/util/symbol.h:135:16: note: declared here
135 | struct symbol *dso__find_symbol_by_name(struct dso *dso, const char *name, size_t *idx);
| ^~~~~~~~~~~~~~~~~~~~~~~~

Fixes: 259dce914e93 ("perf symbol: Remove symbol_name_rb_node")
Acked-by: Ian Rogers <irogers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230627063257.549005-1-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

show more ...

perf build: Add ability to build with a generated vmlinux.h

Commit a887466562b4 ("perf bpf skels: Stop using vmlinux.h generated
from BTF, use subset of used structs + CO-RE") made it so that
vmlinu

perf build: Add ability to build with a generated vmlinux.h

Commit a887466562b4 ("perf bpf skels: Stop using vmlinux.h generated
from BTF, use subset of used structs + CO-RE") made it so that
vmlinux.h was uncondtionally included from
tools/perf/util/vmlinux.h. This change reverts part of that change (so
that vmlinux.h is once again generated) and makes it so that the
vmlinux.h used at build time is selected from the VMLINUX_H
variable. By default the VMLINUX_H variable is set to the vmlinux.h
added in change a887466562b4, but if GEN_VMLINUX_H=1 is passed on the
build command line then the previous generation behavior kicks in.

The build with GEN_VMLINUX_H=1 currently fails with:

util/bpf_skel/lock_contention.bpf.c:419:8: error: redefinition of 'rq'
struct rq {};
^
/tmp/perf/util/bpf_skel/.tmp/../vmlinux.h:45630:8: note: previous definition is here
struct rq {
^
1 error generated.

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: James Clark <james.clark@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230623041405.4039475-2-irogers@google.com
[ Format the error message and add a comment for GEN_VMLINUX_H ]
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

show more ...

perf tests: Make x86 new instructions test optional at build time

The "x86 instruction decoder - new instructions" test takes up space but
is only really useful to developers. Make it optional at bu

perf tests: Make x86 new instructions test optional at build time

The "x86 instruction decoder - new instructions" test takes up space but
is only really useful to developers. Make it optional at build time.

Add variable EXTRA_TESTS which must be defined in order to build perf
with the test.

Example:

Before:

$ make -C tools/perf clean >/dev/null
$ make -C tools/perf >/dev/null
Makefile.config:650: No libunwind found. Please install libunwind-dev[el] >= 1.1 and/or set LIBUNWIND_DIR
Makefile.config:1149: libpfm4 not found, disables libpfm4 support. Please install libpfm4-dev
PERF_VERSION = 6.4.rc3.gd15b8c76c964
$ readelf -SW tools/perf/perf | grep '\.rela.dyn\|.rodata\|\.data.rel.ro'
[10] .rela.dyn RELA 000000000002fcb0 02fcb0 0748b0 18 A 6 0 8
[18] .rodata PROGBITS 00000000002eb000 2eb000 6bac00 00 A 0 0 32
[25] .data.rel.ro PROGBITS 00000000009ea180 9e9180 04b540 00 WA 0 0 32

After:

$ make -C tools/perf clean >/dev/null
$ make -C tools/perf >/dev/null
Makefile.config:650: No libunwind found. Please install libunwind-dev[el] >= 1.1 and/or set LIBUNWIND_DIR
Makefile.config:1154: libpfm4 not found, disables libpfm4 support. Please install libpfm4-dev
PERF_VERSION = 6.4.rc3.g4ea9c1569ea4
$ readelf -SW tools/perf/perf | grep '\.rela.dyn\|.rodata\|\.data.rel.ro'
[10] .rela.dyn RELA 000000000002f3c8 02f3c8 036d68 18 A 6 0 8
[18] .rodata PROGBITS 00000000002ac000 2ac000 68da80 00 A 0 0 32
[25] .data.rel.ro PROGBITS 000000000097d440 97c440 022280 00 WA 0 0 32

Committer notes:

Build with 'make EXTRA_TESTS=1 -C tools/perf O=/tmp/build/perf" and
reproduced the ELF section size differences.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/683fea7c-f5e9-fa20-f96b-f6233ed5d2a7@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

perf build: Don't compile demangle-cxx.cpp if not necessary

demangle-cxx.cpp requires a C++ compiler, but feature checks may fail
because of the absence of this. Add a CONFIG_CXX_DEMANGLE so that th

perf build: Don't compile demangle-cxx.cpp if not necessary

demangle-cxx.cpp requires a C++ compiler, but feature checks may fail
because of the absence of this. Add a CONFIG_CXX_DEMANGLE so that the
source isn't built if not supported. Copy libbfd and cplus demangle
variants to a weak symbol-elf.c version so they aren't dependent on
C++. These variants are only built with the build option
BUILD_NONDISTRO=1.

Committer note:

This also handles this build break when a C++ compiler isn't available:

CXX /tmp/build/perf/util/demangle-cxx.o
/bin/sh: g++: command not found

Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qi Liu <liuqi115@huawei.com>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Link: https://lore.kernel.org/r/20230417192546.99923-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

perf build: Gracefully fail the build if BUILD_BPF_SKEL=1 is specified and clang isn't available

Build BPF skels require having a compiler able to generate BPF bytecode,
and so far this is only poss

perf build: Gracefully fail the build if BUILD_BPF_SKEL=1 is specified and clang isn't available

Build BPF skels require having a compiler able to generate BPF bytecode,
and so far this is only possible with clang, so check for its
availability and fail the build when the user explicitely ask for BPF
skels to be built.

Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>,
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Song Liu <songliubraving@meta.com>
Yang: Yang Jihong <yangjihong1@huawei.com>,
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

Revert "perf build: Make BUILD_BPF_SKEL default, rename to NO_BPF_SKEL"

This reverts commit a980755beb5aca9002e1c95ba519b83a44242b5b.

We need to better polish building with BPF skels, so revert bac

Revert "perf build: Make BUILD_BPF_SKEL default, rename to NO_BPF_SKEL"

This reverts commit a980755beb5aca9002e1c95ba519b83a44242b5b.

We need to better polish building with BPF skels, so revert back to
making it an experimental feature that has to be explicitely enabled
using BUILD_BPF_SKEL=1.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...

Revert "perf build: Warn for BPF skeletons if endian mismatches"

This reverts commit 51924ae69eea5bc90b5da525fbcf4bbd5f8551b3.

We need to better polish building with BPF skels, so revert back to
ma

Revert "perf build: Warn for BPF skeletons if endian mismatches"

This reverts commit 51924ae69eea5bc90b5da525fbcf4bbd5f8551b3.

We need to better polish building with BPF skels, so revert back to
making it an experimental feature that has to be explicitely enabled
using BUILD_BPF_SKEL=1.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

show more ...