kernel/linux.git/tools/build/Makefile.feature, branch v6.12.80

perf build: Remove unused feature test target

2024-09-10T20:32:47+00:00

llvm-version was removed in commit 56b11a2126bf ("perf bpf: Remove support for embedding clang for compiling BPF events (-e foo.c)") but some parts were left in the Makefile so finish removing them. Signed-off-by: James Clark Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Bill Wendling Cc: Changbin Du Cc: Daniel Wagner Cc: Guilherme Amadio Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Justin Stitt Cc: Kan Liang Cc: Leo Yan Cc: Manu Bretelle Cc: Mark Rutland Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Peter Zijlstra Cc: Quentin Monnet Cc: Steinar H. Gunderson Link: https://lore.kernel.org/r/20240910140405.568791-2-james.clark@linaro.org [ Removed one leftover, 'llvm-version' from FEATURE_TESTS_EXTRA ] Signed-off-by: Arnaldo Carvalho de Melo

perf build: Autodetect minimum required llvm-dev version

2024-09-10T20:32:46+00:00

The new LLVM addr2line feature requires a minimum version of 13 to compile. Add a feature check for the version so that NO_LLVM=1 doesn't need to be explicitly added. Leave the existing llvm feature check intact because it's used by tools other than Perf. This fixes the following compilation error when the llvm-dev version doesn't match: util/llvm-c-helpers.cpp: In function 'char* llvm_name_for_code(dso*, const char*, u64)': util/llvm-c-helpers.cpp:178:21: error: 'std::remove_reference_t' {aka 'struct llvm::DILineInfo'} has no member named 'StartAddress' 178 | addr, res_or_err->StartAddress ? *res_or_err->StartAddress : 0); Fixes: c3f8644c21df9b7d ("perf report: Support LLVM for addr2line()") Signed-off-by: James Clark Tested-by: Arnaldo Carvalho de Melo Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Bill Wendling Cc: Changbin Du Cc: Guilherme Amadio Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Justin Stitt Cc: Kan Liang Cc: Leo Yan Cc: Manu Bretelle Cc: Mark Rutland Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Peter Zijlstra Cc: Quentin Monnet Cc: Steinar H. Gunderson Link: https://lore.kernel.org/r/20240910140405.568791-1-james.clark@linaro.org Signed-off-by: Arnaldo Carvalho de Melo

perf report: Support LLVM for addr2line()

2024-09-03T13:15:16+00:00

In addition to the existing support for libbfd and calling out to an external addr2line command, add support for using libllvm directly. This is both faster than libbfd, and can be enabled in distro builds (the LLVM license has an explicit provision for GPLv2 compatibility). Thus, it is set as the primary choice if available. As an example, running 'perf report' on a medium-size profile with DWARF-based backtraces took 58 seconds with LLVM, 78 seconds with libbfd, 153 seconds with external llvm-addr2line, and I got tired and aborted the test after waiting for 55 minutes with external bfd addr2line (which is the default for perf as compiled by distributions today). Evidently, for this case, the bfd addr2line process needs 18 seconds (on a 5.2 GHz Zen 3) to load the .debug ELF in question, hits the 1-second timeout and gets killed during initialization, getting restarted anew every time. Having an in-process addr2line makes this much more robust. As future extensions, libllvm can be used in many other places where we currently use libbfd or other libraries: - Symbol enumeration (in particular, for PE binaries). - Demangling (including non-Itanium demangling, e.g. Microsoft or Rust). - Disassembling (perf annotate). However, these are much less pressing; most people don't profile PE binaries, and perf has non-bfd paths for ELF. The same with demangling; the default _cxa_demangle path works fine for most users, and while bfd objdump can be slow on large binaries, it is possible to use --objdump=llvm-objdump to get the speed benefits. (It appears LLVM-based demangling is very simple, should we want that.) Tested with LLVM 14, 15, 16, 18 and 19. For some reason, LLVM 12 was not correctly detected using feature_check, and thus was not tested. Committer notes: Added the name and a __maybe_unused to address: 1 13.50 almalinux:8 : FAIL gcc version 8.5.0 20210514 (Red Hat 8.5.0-22) (GCC) util/srcline.c: In function 'dso__free_a2l': util/srcline.c:184:20: error: parameter name omitted void dso__free_a2l(struct dso *) ^~~~~~~~~~~~ make[3]: *** [/git/perf-6.11.0-rc3/tools/build/Makefile.build:158: util] Error 2 Signed-off-by: Steinar H. Gunderson Tested-by: Arnaldo Carvalho de Melo Cc: Ian Rogers Link: https://lore.kernel.org/r/20240803152008.2818485-1-sesse@google.com Signed-off-by: Arnaldo Carvalho de Melo

tools: Make pkg-config dependency checks usable by other tools

2024-07-17T20:14:35+00:00

Other tools, in tools/verification and tools/tracing, make use of libtraceevent and libtracefs as dependencies. This allows setting up the feature check flags for them as well. Signed-off-by: Guilherme Amadio Tested-by: Thorsten Leemhuis Tested-by: Leo Yan Acked-by: Steven Rostedt (Google) Cc: linux-trace-devel@vger.kernel.org Link: https://lore.kernel.org/r/20240717174739.186988-3-amadio@gentoo.org Signed-off-by: Namhyung Kim

perf: build: introduce the libcapstone

2024-02-21T02:06:25+00:00

Later we will use libcapstone to disassemble instructions of samples. Signed-off-by: Changbin Du Reviewed-by: Adrian Hunter Cc: changbin.du@gmail.com Cc: Thomas Richter Cc: Andi Kleen Signed-off-by: Namhyung Kim Link: https://lore.kernel.org/r/20240217074046.4100789-2-changbin.du@huawei.com

perf build: Add feature check for dwarf_getcfi()

2023-11-10T12:04:16+00:00

The dwarf_getcfi() is available on libdw 0.142+. Instead of just checking the version number, it'd be nice to have a config item to check the feature at build time. Suggested-by: Masami Hiramatsu (Google) Signed-off-by: Namhyung Kim Acked-by: Masami Hiramatsu (Google) Cc: Adrian Hunter Cc: Andi Kleen Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Stephane Eranian Cc: linux-toolchains@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Link: https://lore.kernel.org/r/20231110000012.3538610-9-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

tools build: Add a feature test for scandirat(), that is not implemented so far in musl and uclibc

2023-04-04T16:18:17+00:00

We use it just when listing tracepoint events, and for root, so just emit a warning about it to get users to ask the library maintainers to implement it, as suggested in this systemd ticket: https://github.com/systemd/casync/issues/129 Cc: Adrian Hunter Cc: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lore.kernel.org/lkml/ZCwv4z5Dh%2FdHUMG6@kernel.org/ Signed-off-by: Arnaldo Carvalho de Melo

tools build: Add feature test for abi::__cxa_demangle

2023-03-14T11:29:46+00:00

cxxabi.h is part of libsdtc++ and LLVM's libcxx, providing abi::__cxa_demangle a portable C++ demangler. Add a feature test to detect that the function is available. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Andres Freund Cc: Ingo Molnar Cc: Jiri Olsa Cc: Leo Yan Cc: Mark Rutland Cc: Martin Liška Cc: Namhyung Kim Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Pavithra Gurushankar Cc: Peter Zijlstra Cc: Quentin Monnet Cc: Roberto Sassu Cc: Stephane Eranian Cc: Tiezhu Yang Cc: Tom Rix Cc: Yang Jihong Cc: llvm@lists.linux.dev Link: https://lore.kernel.org/r/20230311065753.3012826-2-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf bpf: Fix build with libbpf 0.7.0 by checking if bpf_program__set_insns() is available

2022-10-25T20:40:48+00:00

During the transition to libbpf 1.0 some functions that perf used were deprecated and finally removed from libbpf, so bpf_program__set_insns() was introduced for perf to continue to use its bpf loader. But when build with LIBBPF_DYNAMIC=1 we now need to check if that function is available so that perf can build with older libbpf versions, even if the end result is emitting a warning to the user that the use of the perf BPF loader requires a newer libbpf, since bpf_program__set_insns() touches libbpf objects internal state. This affects only 'perf trace' when using bpf C code or pre-compiled bytecode as an event. Noticed on RHEL9, that has libbpf 0.7.0, where bpf_program__set_insns() isn't available. Signed-off-by: Arnaldo Carvalho de Melo

tools build: Display logical OR of a feature flavors

2022-10-04T11:55:19+00:00

Sometimes, features are simply different flavors of another feature, to properly detect the exact dependencies needed by different Linux distributions. For example, libbfd has three flavors: libbfd if the distro does not require any additional dependency; libbfd-liberty if it requires libiberty; libbfd-liberty-z if it requires libiberty and libz. It might not be clear to the user whether a feature has been successfully detected or not, given that some of its flavors will be set to OFF, others to ON. Instead, display only the feature main flavor if not in verbose mode (VF != 1), and set it to ON if at least one of its flavors has been successfully detected (logical OR), OFF otherwise. Omit the other flavors. Accomplish that by declaring a FEATURE_GROUP_MEMBERS- variable, with the list of the other flavors as variable value. For now, do it just for libbfd. In verbose mode, of if no group is defined for a feature, show the feature detection result as before. Committer testing: Collecting the output from: $ make -C tools/bpf/bpftool/ clean $ make -C tools/bpf/bpftool/ |& grep "Auto-detecting system features" -A10 $ diff -u before after --- before 2022-08-18 10:06:40.422086966 -0300 +++ after 2022-08-18 10:07:59.202138282 -0300 @@ -1,6 +1,4 @@ Auto-detecting system features: ... libbfd: [ on ] -... libbfd-liberty: [ on ] -... libbfd-liberty-z: [ on ] ... libcap: [ on ] ... clang-bpf-co-re: [ on ] $ Signed-off-by: Roberto Sassu Tested-by: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Ingo Molnar Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Quentin Monnet Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20220818120957.319995-3-roberto.sassu@huaweicloud.com Signed-off-by: Arnaldo Carvalho de Melo