kernel/linux.git/tools/build/feature, branch v7.0-rc7

tools build: Fix feature test for rust compiler

2026-02-12T20:45:22+00:00

Currently a dummy rust code is compiled to detect if the rust feature could be enabled. It turns out that in this case rust emits a dependency file without any external references: /perf/feature/test-rust.d: test-rust.rs /perf/feature/test-rust.bin: test-rust.rs test-rust.rs: This can lead to a situation, when rustc was removed after a successful build, but the build process still thinks it's there and the feature is enabled on subsequent runs. Instead simply check the compiler presence to detect the feature, as suggested by Arnaldo. This way no actual test-rust.bin will be created, meaning the feature check will not be cached and always performed. That's exactly what we want, and the overhead of doing this every time is minimal. Tested with multiple rounds of install/remove of the rust package. Reported-by: Arnaldo Carvalho de Melo Suggested-by: Arnaldo Carvalho de Melo Signed-off-by: Dmitrii Dolgov <9erthalion6@gmail.com> Tested-by: Arnaldo Carvalho de Melo Cc: Ian Rogers Cc: Miguel Ojeda Cc: Namhyung Kim Signed-off-by: Arnaldo Carvalho de Melo

tools build: Emit dependencies file for test-rust.bin

2026-02-10T12:29:58+00:00

Test it first by having rust installed, then removing it and building again. Fixes: 6a32fa5ccd33da5d ("tools build: Add a feature test for rust compiler") Signed-off-by: Dmitry Dolgov <9erthalion6@gmail.com> Signed-off-by: Arnaldo Carvalho de Melo

tools build: Make test-rust.bin be removed by the 'clean' target

2026-02-10T12:29:39+00:00

test-rust.bin is missing from the list of FILES, and thus is not removed by the clean target. This could lead to a false feature detection, since the binary stays there. Fix it. Fixes: 6a32fa5ccd33da5d ("tools build: Add a feature test for rust compiler") Tested-by: Arnaldo Carvalho de Melo Signed-off-by: Dmitrii Dolgov <9erthalion6@gmail.com> Signed-off-by: Arnaldo Carvalho de Melo

tools build: Add a feature test for rust compiler

2026-02-08T14:30:45+00:00

Add a feature test to identify if the rust compiler is available, so that perf could build rust based worloads based on that. Signed-off-by: Dmitrii Dolgov <9erthalion6@gmail.com> Cc: Ian Rogers Cc: Namhyung Kim Signed-off-by: Arnaldo Carvalho de Melo

perf build: Feature test for libbfd thread safety API

2026-01-06T22:14:46+00:00

The non-distro build requires libbfd 2.42 since commit b72b8132d8fd ("perf libbfd: Ensure libbfd is initialized prior to use"). Add a feature test so that it's obvious why the build fails if this criteria isn't met. Signed-off-by: James Clark Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Bill Wendling Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Justin Stitt Cc: Leo Yan Cc: Mark Rutland Cc: Namhyung Kim Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Peter Zijlstra Signed-off-by: Arnaldo Carvalho de Melo

perf build: Remove unused libbfd-buildid feature test

2026-01-06T22:14:00+00:00

HAVE_LIBBFD_BUILDID_SUPPORT isn't used in the codebase so remove the feature test that sets it. Signed-off-by: James Clark Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Bill Wendling Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Justin Stitt Cc: Leo Yan Cc: Mark Rutland Cc: Namhyung Kim Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Peter Zijlstra Signed-off-by: Arnaldo Carvalho de Melo

tools build: Fix the common set of features test wrt libopenssl

2025-12-28T04:26:44+00:00

The recent introduction of the libopenssl feature test forgot to add the -lssl to the test-all.o target, which made it always fail, fix it. Noticed by looking at this file after building: $ cat /tmp/build/perf-tools/feature/test-all.make.output /usr/bin/ld: /tmp/ccBhO8WH.ltrans0.ltrans.o: in function `main': /home/acme/git/perf-tools/tools/build/feature/test-libopenssl.c:6:(.text.startup+0x2ed): undefined reference to `OPENSSL_init_ssl' collect2: error: ld returned 1 exit status $ It was added only to the individual ssl test, that works: $ cat /tmp/build/perf-tools/feature/test-libopenssl.make.output $ ldd /tmp/build/perf-tools/feature/test-libopenssl.bin | grep ssl libssl.so.3 => /usr/lib64/libssl.so.3 (0x00007fb81eda8000) $ Fixes: 7678523109d1d9ee ("tools/build: Add a feature test for libopenssl") Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Namhyung Kim

tools/build: Add a feature test for libopenssl

2025-12-17T13:44:24+00:00

It's used by bpftool and the kernel build. Let's add a feature test so that perf can decide what to do based on the availability. Signed-off-by: Namhyung Kim

Merge tag 'perf-tools-for-v6.19-2025-12-06' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools

2025-12-07T15:07:02+00:00

Pull perf tools updates from Namhyung Kim: "Perf event/metric description: Unify all event and metric descriptions in JSON format. Now event parsing and handling is greatly simplified by that. From users point of view, perf list will provide richer information about hardware events like the following. $ perf list hw List of pre-defined events (to be used in -e or -M): legacy hardware: branch-instructions [Retired branch instructions [This event is an alias of branches]. Unit: cpu] branch-misses [Mispredicted branch instructions. Unit: cpu] branches [Retired branch instructions [This event is an alias of branch-instructions]. Unit: cpu] bus-cycles [Bus cycles,which can be different from total cycles. Unit: cpu] cache-misses [Cache misses. Usually this indicates Last Level Cache misses; this is intended to be used in conjunction with the PERF_COUNT_HW_CACHE_REFERENCES event to calculate cache miss rates. Unit: cpu] cache-references [Cache accesses. Usually this indicates Last Level Cache accesses but this may vary depending on your CPU. This may include prefetches and coherency messages; again this depends on the design of your CPU. Unit: cpu] cpu-cycles [Total cycles. Be wary of what happens during CPU frequency scaling [This event is an alias of cycles]. Unit: cpu] cycles [Total cycles. Be wary of what happens during CPU frequency scaling [This event is an alias of cpu-cycles]. Unit: cpu] instructions [Retired instructions. Be careful,these can be affected by various issues,most notably hardware interrupt counts. Unit: cpu] ref-cycles [Total cycles; not affected by CPU frequency scaling. Unit: cpu] But most notable changes would be in the perf stat. On the right side, the default metrics are better named and aligned. :) $ perf stat -- perf test -w noploop Performance counter stats for 'perf test -w noploop': 11 context-switches # 10.8 cs/sec cs_per_second 0 cpu-migrations # 0.0 migrations/sec migrations_per_second 3,612 page-faults # 3532.5 faults/sec page_faults_per_second 1,022.51 msec task-clock # 1.0 CPUs CPUs_utilized 110,466 branch-misses # 0.0 % branch_miss_rate (88.66%) 6,934,452,104 branches # 6781.8 M/sec branch_frequency (88.66%) 4,657,032,590 cpu-cycles # 4.6 GHz cycles_frequency (88.65%) 27,755,874,218 instructions # 6.0 instructions insn_per_cycle (89.03%) TopdownL1 # 0.3 % tma_backend_bound # 9.3 % tma_bad_speculation (89.05%) # 9.7 % tma_frontend_bound (77.86%) # 80.7 % tma_retiring (88.81%) 1.025318171 seconds time elapsed 1.013248000 seconds user 0.012014000 seconds sys Deferred unwinding support: With the kernel support (commit c69993ecdd4d: "perf: Support deferred user unwind"), perf can use deferred callchains for userspace stack trace with frame pointers like below: $ perf record --call-graph fp,defer ... This will be transparent to users when it comes to other commands like perf report and perf script. They will merge the deferred callchains to the previous samples as if they were collected together. ARM SPE updates - Extensive enhancements to support various kinds of memory operations including GCS, MTE allocation tags, memcpy/memset, register access, and SIMD operations. - Add inverted data source filter (inv_data_src_filter) support to exclude certain data sources. - Improve documentation. Vendor event updates: - Intel: Updated event files for Sierra Forest, Panther Lake, Meteor Lake, Lunar Lake, Granite Rapids, and others. - Arm64: Added metrics for i.MX94 DDR PMU and Cortex-A720AE definitions. - RISC-V: Added JSON support for T-HEAD C920V2. Misc: - Improve pointer tracking in data type profiling. It'd give better output when the variable is using container_of() to convert type. - Annotation support for perf c2c report in TUI. Press 'a' key to enter annotation view from cacheline browser window. This will show which instruction is causing the cacheline contention. - Lots of fixes and test coverage improvements!" * tag 'perf-tools-for-v6.19-2025-12-06' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (214 commits) libperf: Use 'extern' in LIBPERF_API visibility macro perf stat: Improve handling of termination by signal perf tests stat: Add test for error for an offline CPU perf stat: When no events, don't report an error if there is none perf tests stat: Add "--null" coverage perf cpumap: Add "any" CPU handling to cpu_map__snprint_mask libperf cpumap: Fix perf_cpu_map__max for an empty/NULL map perf stat: Allow no events to open if this is a "--null" run perf test kvm: Add some basic perf kvm test coverage perf tests evlist: Add basic evlist test perf tests script dlfilter: Add a dlfilter test perf tests kallsyms: Add basic kallsyms test perf tests timechart: Add a perf timechart test perf tests top: Add basic perf top coverage test perf tests buildid: Add purge and remove testing perf tests c2c: Add a basic c2c perf c2c: Clean up some defensive gets and make asan clean perf jitdump: Fix missed dso__put perf mem-events: Don't leak online CPU map perf hist: In init, ensure mem_info is put on error paths ...

tool build: Remove __get_cpuid feature test

2025-11-14T07:03:11+00:00

This feature test is no longer used so remove. The function tested by the feature test is used in: tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c however, the Makefile just assumes the presence of the function and doesn't perform a build feature test for it. Signed-off-by: Ian Rogers Reviewed-by: James Clark Signed-off-by: Namhyung Kim