kernel/linux.git/tools/perf/Makefile.config, branch v7.2-rc2

perf s390: Fix TEXTREL in Python extension by compiling as PIC

2026-06-10T20:03:53+00:00

On s390 the Python extension build fails as follows when using a linker that is configured to treat text relocations (TEXTREL) in shared libraries as error by default: GEN python/perf.cpython-314-s390x-linux-gnu.so /usr/bin/ld.bfd: error: read-only segment has dynamic relocations This occurrs because util/llvm-c-helpers.o is erroneously built from util/llvm-c-helpers.cpp without compiler option -fPIC but linked into the shared library (via libperf-util.a(perf-util-in.o)). On s390, object files must be compiled as position-indepedent code (PIC) in order to be linked into shared libraries. Commit a9a3f1d18a6c ("perf s390: Always build with -fPIC") added compiler option -fPIC to CFLAGS for s390, which is used in C compiles. Add -fPIC to CXXFLAGS for s390 as well, so that it is also used in C++ compiles. Fixes: a9a3f1d18a6c9ccf ("perf s390: Always build with -fPIC") Reported-by: Thomas Richter Reviewed-by: Ian Rogers Reviewed-by: James Clark Signed-off-by: Jens Remus Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Bill Wendling Cc: Heiko Carstens Cc: Hendrik Brueckner Cc: Ingo Molnar Cc: Jan Polensky Cc: Jiri Olsa Cc: Justin Stitt Cc: Mark Rutland Cc: Namhyung Kim Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Peter Zijlstra Signed-off-by: Arnaldo Carvalho de Melo

perf data ctf: replace libbabeltrace with babeltrace2-ctf-writer

2026-06-04T20:34:52+00:00

The 1.x branch of Babeltrace has been superseded by 2.x in 2020 and has been unmaintained since 2022, efforts have started to remove it from popular distributions. Babeltrace 2.x offers a very similar 'ctf-writer' library that can be used with minimal changes for the '--to-ctf' feature and has been packaged since Debian 11 and Fedora 32. This patch replaces the 'libbabeltrace' build feature with 'babeltrace2-ctf-writer' using pkgconfig detection, adjusts the naming of the public headers and applies minor API cleanups. There is no changes to the output ctf traces, the ctf-writer API still implements version 1.8 of the CTF specification that can be read by either Babeltrace 1 / 2 or any CTF compliant reader. Also remove some ifdefs in the cli option parsing to allow printing the helpful error message with '--to-ctf' when built without babeltrace2. Reviewed-by: Ian Rogers Signed-off-by: Michael Jeanson Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Derek Foreman Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Mark Rutland Cc: Mathieu Desnoyers Cc: Namhyung Kim Cc: Peter Zijlstra Signed-off-by: Arnaldo Carvalho de Melo

perf build: Unconditionally set up libunwind feature build flags

2026-05-22T23:50:18+00:00

A "make feature-dump" build does not specify LIBUNWIND=1 because it is run with the default configuration to detect system-wide capabilities. This sets NO_LIBUNWIND := 1, causing Makefile.config to skip setting LIBUNWIND_LIBS and FEATURE_CHECK_LDFLAGS-libunwind. Consequently, when Makefile.feature is included and attempts to run all feature checks (via FEATURE_TESTS := all), the local feature test test-libunwind.bin compiles without the required architecture-specific library flags (-lunwind-x86_64) and fails to link on x86_64. This results in a corrupted cached BUILD_TEST_FEATURE_DUMP showing feature-libunwind=0 even when the host supports it. Subsequent test builds (like make_libunwind_O in the build-test suite) which reuse the feature dump and specify LIBUNWIND=1 will fail to compile due to a mismatch where CONFIG_LIBUNWIND is set (via remote architecture checks which are self-contained) but HAVE_LIBUNWIND_SUPPORT is disabled, causing compiler errors due to missing maps__e_machine definitions in maps.h. Fix this by unconditionally setting up the libunwind library lists and feature check LDFLAGS in Makefile.config so they are always populated and available to the feature detection engine regardless of whether LIBUNWIND=1 is opted-in for the current run. Fixes: 444508cd7c7b4f05 ("perf build: Be more programmatic when setting up libunwind variables") Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Ian Rogers Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Signed-off-by: Arnaldo Carvalho de Melo

perf build: Convert llvm-config shell queries to simply expanded variables

2026-05-20T21:23:49+00:00

In Makefile.config, CFLAGS, CXXFLAGS, LIBLLVM, and EXTLIBS were assigned using recursive expansion or appended with raw $(shell $(LLVM_CONFIG) ...) calls. Because these variables were expanded during dependency evaluation across every single object file compilation rule, Kbuild continuously re-executed llvm-config forks nearly 200 times during incremental builds. Convert llvm-config shell queries to simply expanded variables (:=) to ensure Make evaluates LLVM compiler flags and library paths exactly once when Makefile.config is parsed, eliminating ~185 redundant sub-processes during build startup. Reviewed-by: Namhyung Kim Assisted-by: Gemini:gemini-3.1-pro-preview Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Albert Ou Cc: Alexandre Chartre Cc: Alexandre Ghiti Cc: Andrii Nakryiko Cc: Ankur Arora Cc: Collin Funk Cc: Costa Shulyupin Cc: Daniel Borkmann Cc: Dapeng Mi Cc: David Sterba Cc: Dmitrii Dolgov <9erthalion6@gmail.com> Cc: Eduard Zingerman Cc: Howard Chu Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Kumar Kartikeya Dwivedi Cc: Leo Yan Cc: Markus Mayer Cc: Martin KaFai Lau Cc: Nathan Chancellor Cc: Nick Terrell Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Quentin Monnet Cc: Ricky Ringler Cc: Song Liu Cc: Swapnil Sapkal Cc: Thomas Falcon Cc: Tomas Glozar Cc: Yonghong Song Signed-off-by: Arnaldo Carvalho de Melo

perf build: Remove redundant libbpf feature check for static builds

2026-05-20T20:46:45+00:00

By default, the perf tool compiles and statically links against its own internal copy of libbpf (tools/lib/bpf/libbpf.a), setting LIBBPF_STATIC=1. Despite this static linkage, Makefile.config unconditionally executed $(call feature_check,libbpf), which forced a synchronous sub-make fork during AST parsing to detect dynamic system libbpf libraries. As noted in the internal Makefile comments, this check was executed purely so that running `make VF=1` would display the detection status of system libbpf. During standard builds without LIBBPF_DYNAMIC=1, the detection result was entirely ignored. Wrap the libbpf feature check inside LIBBPF_DYNAMIC=1 so Make avoids the redundant sub-make fork overhead during standard static builds. Reviewed-by: Namhyung Kim Assisted-by: Gemini:gemini-3.1-pro-preview Signed-off-by: Ian Rogers Tested-by: James Clark Cc: Adrian Hunter Cc: Albert Ou Cc: Alexandre Chartre Cc: Alexandre Ghiti Cc: Andrii Nakryiko Cc: Ankur Arora Cc: Collin Funk Cc: Costa Shulyupin Cc: Daniel Borkmann Cc: Dapeng Mi Cc: David Sterba Cc: Dmitrii Dolgov <9erthalion6@gmail.com> Cc: Eduard Zingerman Cc: Howard Chu Cc: Ingo Molnar Cc: Jiri Olsa Cc: Kumar Kartikeya Dwivedi Cc: Leo Yan Cc: Markus Mayer Cc: Martin KaFai Lau Cc: Nathan Chancellor Cc: Nick Terrell Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Quentin Monnet Cc: Ricky Ringler Cc: Song Liu Cc: Swapnil Sapkal Cc: Thomas Falcon Cc: Tomas Glozar Cc: Yonghong Song Signed-off-by: Arnaldo Carvalho de Melo

perf build: Encapsulate vmlinux.h and bpftool in bpf_skel.mak

2026-05-20T20:46:45+00:00

Currently, bpftool and vmlinux.h are prerequisites of the top-level prepare target in Makefile.perf. This unnecessarily blocks the massive parallel C compilation of libraries (perf-util, perf-ui, pmu-events) during the initial startup phase. Move all bpftool and vmlinux.h generation rules down into tools/perf/bpf_skel.mak to encapsulate BPF tooling completely within the skeleton framework. Remove them entirely from prepare to unblock immediate parallel build execution. To prevent parallel sub-makes (perf-util and perf-bench) from racing to build shared prerequisites concurrently, while maintaining strict directory encapsulation without top-level inclusions, serialize bench after the util static archive finishes using an order-only prerequisite: $(LIBPERF_BENCH_IN): FORCE prepare | $(LIBPERF_UTIL) Reviewed-by: Namhyung Kim Assisted-by: Gemini:gemini-3.1-pro-preview Signed-off-by: Ian Rogers Tested-by: James Clark Cc: Adrian Hunter Cc: Albert Ou Cc: Alexandre Chartre Cc: Alexandre Ghiti Cc: Andrii Nakryiko Cc: Ankur Arora Cc: Collin Funk Cc: Costa Shulyupin Cc: Daniel Borkmann Cc: Dapeng Mi Cc: David Sterba Cc: Dmitrii Dolgov <9erthalion6@gmail.com> Cc: Eduard Zingerman Cc: Howard Chu Cc: Ingo Molnar Cc: Jiri Olsa Cc: Kumar Kartikeya Dwivedi Cc: Leo Yan Cc: Markus Mayer Cc: Martin KaFai Lau Cc: Nathan Chancellor Cc: Nick Terrell Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Quentin Monnet Cc: Ricky Ringler Cc: Song Liu Cc: Swapnil Sapkal Cc: Thomas Falcon Cc: Tomas Glozar Cc: Yonghong Song Signed-off-by: Arnaldo Carvalho de Melo

perf build: Be more programmatic when setting up libunwind variables

2026-05-15T11:26:11+00:00

Iterate LIBUNWIND_ARCHS when setting up CONFIG_ and HAVE_ definitions rather than treating each architecture individually. This sets up the libunwind build variables and C definitions beyond x86 and arm/aarch64. The existing naming convention is followed for compatibility. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Albert Ou Cc: Alexander Shishkin Cc: Alexandre Ghiti Cc: Andrew Jones Cc: Athira Rajeev Cc: Dapeng Mi Cc: Dmitrii Dolgov <9erthalion6@gmail.com> Cc: Florian Fainelli Cc: Howard Chu Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: John Garry Cc: Leo Yan Cc: Li Guan Cc: Namhyung Kim Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Shimin Guo Cc: Thomas Richter Cc: Tomas Glozar Cc: Will Deacon Signed-off-by: Arnaldo Carvalho de Melo

perf build: Update error message for BUILD_NONDISTRO=1

2026-05-06T01:06:44+00:00

It should say binutils-dev(el) instead of plain binutils package as it's mostly installed already and can confuse people like me. :) Reviewed-by: Ian Rogers Signed-off-by: Namhyung Kim Cc: Adrian Hunter Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Peter Zijlstra Signed-off-by: Arnaldo Carvalho de Melo

perf build: Add -funsigned-char to default CFLAGS

2026-04-01T03:22:02+00:00

Commit 3bc753c06dd0 ("kbuild: treat char as always unsigned") made chars unsigned by default in the Linux kernel. To avoid similar kinds of bugs and warnings, make unsigned chars the default for the perf tool. Signed-off-by: Ian Rogers Signed-off-by: Namhyung Kim

tools build: Fix rust cross compilation

2026-03-04T14:37:30+00:00

Currently no target is specified to compile rust code when needed, which breaks cross compilation. E.g. for arm64: LD /tmp/build/tests/workloads/perf-test-in.o aarch64-linux-gnu-ld: /tmp/build/tests/workloads/code_with_type.a(code_with_type.code_with_type.d12f4324cb53c560-cgu.0.rcgu.o): Relocations in generic ELF (EM: 62) aarch64-linux-gnu-ld: /tmp/build/tests/workloads/code_with_type.a(code_with_type.code_with_type.d12f4324cb53c560-cgu.0.rcgu.o): Relocations in generic ELF (EM: 62) [...repeated...] aarch64-linux-gnu-ld: /tmp/build/tests/workloads/code_with_type.a(code_with_type.code_with_type.d12f4324cb53c560-cgu.0.rcgu.o): Relocations in generic ELF (EM: 62) aarch64-linux-gnu-ld: /tmp/build/tests/workloads/code_with_type.a(code_with_type.code_with_type.d12f4324cb53c560-cgu.0.rcgu.o): Relocations in generic ELF (EM: 62) aarch64-linux-gnu-ld: /tmp/build/tests/workloads/code_with_type.a: error adding symbols: file in wrong format make[5]: *** [/perf/tools/build/Makefile.build:162: /tmp/build/tests/workloads/perf-test-in.o] Error 1 make[4]: *** [/perf/tools/build/Makefile.build:156: workloads] Error 2 make[3]: *** [/perf/tools/build/Makefile.build:156: tests] Error 2 make[2]: *** [Makefile.perf:785: /tmp/build/perf-test-in.o] Error 2 make[2]: *** Waiting for unfinished jobs.... make[1]: *** [Makefile.perf:289: sub-make] Error 2 make: *** [Makefile:76: all] Error 2 Detect required target and pass it via rust_flags to the compiler. Note that CROSS_COMPILE might be different from what rust compiler expects, since it may omit the target vendor value, e.g. "aarch64-linux-gnu" instead of "aarch64-unknown-linux-gnu". Thus explicitly map supported CROSS_COMPILE values to corresponding Rust versions, as suggested by Miguel Ojeda. Tested using arm64 cross-compilation example from [1]. Fixes: 2e05bb52a12d3cdb ("perf test workload: Add code_with_type test workload") Reviewed-by: Ian Rogers Signed-off-by: Dmitrii Dolgov <9erthalion6@gmail.com> Cc: Levi Zim Cc: Miguel Ojeda Cc: Namhyung Kim Cc: Nathan Chancellor Cc: Nicolas Schier Link: https://perfwiki.github.io/main/arm64-cross-compilation-dockerfile/ [1] Signed-off-by: Arnaldo Carvalho de Melo