kernel/linux.git/tools/tracing/rtla/Makefile, branch v6.18.21

Merge tag 'trace-tools-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2025-03-28T00:03:01+00:00

Pull tracing tooling updates from Steven Rostedt: - Allow RTLA to collect data via BPF The current implementation of rtla uses libtracefs and libtraceevent to pull sample events generated by the timerlat tracer from the trace buffer. rtla then processes the sample by updating the histogram and summary (current, maximum, minimum, and sum values) as well as checks if tracing has been stopped due to threshold overflow. In use cases where a large number of samples is being generated, that is, with measurements running on many CPUs and with a low interval, this sample processing design causes a significant CPU load on the rtla side. Furthermore, with >100 CPUs and 100us interval, rtla was reported as not being able to keep up with the samples and dropping most of them, leading to it being unusable. Change the way the timerlat trace processes samples by attaching a BPF program to the trace event using the BPF skeleton feature of bpftool. Unlike the current implementation, the BPF implementation does not check whether tracing is stopped (in BPF mode, tracing is always off to improve performance), but waits for a write to a BPF ringbuffer instead. This allows rtla to exit immediately when a threshold is violated, without waiting for the next iteration of the while loop. If the requirements for the BPF implementation are not met, either at build time or at run time, the current implementation is used as fallback. Which implementation is being used can be seen when running rtla timerlat with "-D" option. rtla can be forced to run in non-BPF mode by setting the RTLA_NO_BPF option to 1, for debugging purposes. - Fix LD_FLAGS from being dropped in build - Refactor code to remove duplication of save_trace_to_file - Always set options and do not rely on default settings Do not rely on the default kernel settings of the tracers when starting. They could have been changed by the user which gives inconsistent results. Always set the options that rtla expects. - Add creation of ctags and TAGS for traversing code * tag 'trace-tools-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: rtla: Add the ability to create ctags and etags rtla/tests: Test setting default options rtla/tests: Reset osnoise options before check rtla: Always set all tracer options rtla/osnoise: Set OSNOISE_WORKLOAD to true rtla: Unify apply_config between top and hist rtla/osnoise: Unify params struct rtla: Fix segfault in save_trace_to_file call tools/build: Use SYSTEM_BPFTOOL for system bpftool rtla: Refactor save_trace_to_file tools/rv: Keep user LDFLAGS in build rtla/timerlat: Test BPF mode rtla/timerlat_top: Use BPF to collect samples rtla/timerlat_top: Move divisor to update rtla/timerlat_hist: Use BPF to collect samples rtla/timerlat: Add BPF skeleton to collect samples rtla: Add optional dependency on BPF tooling tools/build: Add bpftool-skeletons feature test rtla/timerlat: Unify params struct

tools/build: Use SYSTEM_BPFTOOL for system bpftool

2025-03-26T14:31:31+00:00

The feature test for system bpftool uses BPFTOOL as the variable to set its path, defaulting to just "bpftool" if not set by the user. This conflicts with selftests and a few other utilities, which expect BPFTOOL to be set to the in-tree bpftool path by default. For example, bpftool selftests fail to build: $ make -C tools/testing/selftests/bpf/ make: Entering directory '/home/tglozar/dev/linux/tools/testing/selftests/bpf' make: *** No rule to make target 'bpftool', needed by '/home/tglozar/dev/linux/tools/testing/selftests/bpf/tools/include/vmlinux.h'. Stop. make: Leaving directory '/home/tglozar/dev/linux/tools/testing/selftests/bpf' Fix the problem by renaming the variable used for system bpftool from BPFTOOL to SYSTEM_BPFTOOL, so that the new usage does not conflict with the existing one of BPFTOOL. Cc: John Kacur Cc: Luis Goncalves Link: https://lore.kernel.org/20250326004018.248357-1-tglozar@redhat.com Fixes: 8a635c3856dd ("tools/build: Add bpftool-skeletons feature test") Closes: https://lore.kernel.org/linux-kernel/5df6968a-2e5f-468e-b457-fc201535dd4c@linux.ibm.com/ Reported-by: Venkat Rao Bagalkote Tested-by: Venkat Rao Bagalkote Suggested-by: Quentin Monnet Acked-by: Quentin Monnet Signed-off-by: Tomas Glozar Signed-off-by: Steven Rostedt (Google)

rtla/timerlat: Add BPF skeleton to collect samples

2025-03-04T17:35:18+00:00

Add BPF program that attaches to the osnoise:timerlat_sample tracepoint and collects both the summary and the histogram (if requested) into BPF maps (one map of each kind per context). The program is designed to be used for both timerlat-top and timerlat-hist. If using with timerlat-top, the "entries" parameter is set to zero, which prevents the BPF program from recording histogram entries. In that case, the maps for histograms do not have to be created, as the BPF verifier will identify the code using them as unreachable. An IRQ or thread latency threshold might be supplied to stop recording if hit, similar to the timerlat tracer threshold, which stops ftrace tracing if hit. A BPF ringbuffer is used to signal threshold overflow to userspace. In aa-only mode, this is the only function of the BPF program. Cc: John Kacur Cc: Luis Goncalves Cc: Gabriele Monaco Cc: Clark Williams Link: https://lore.kernel.org/20250218145859.27762-5-tglozar@redhat.com Signed-off-by: Tomas Glozar Signed-off-by: Steven Rostedt (Google)

rtla: Add optional dependency on BPF tooling

2025-03-04T17:35:17+00:00

If tooling required for building BPF CO-RE skeletons is present (that is, libbpf, clang with BPF CO-RE support, and bpftool), turn on HAVE_BPF_SKEL flag. Those requirements are similar to what perf requires, with the difference of using system libbpf and bpftool instead of in-tree versions. rtla can be forcefully built without BPF skeleton support by setting BUILD_BPF_SKEL=0 manually; in that case, a warning is displayed. Cc: John Kacur Cc: Luis Goncalves Cc: Gabriele Monaco Cc: Clark Williams Link: https://lore.kernel.org/20250218145859.27762-4-tglozar@redhat.com Signed-off-by: Tomas Glozar Signed-off-by: Steven Rostedt (Google)

Merge tag 'perf-tools-fixes-for-v6.14-2-2025-02-25' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools

2025-02-25T21:32:32+00:00

Pull perf tools fixes from Arnaldo Carvalho de Melo: - Fix tools/ quiet build Makefile infrastructure that was broken when working on tools/perf/ without testing on other tools/ living utilities. * tag 'perf-tools-fixes-for-v6.14-2-2025-02-25' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: tools: Remove redundant quiet setup tools: Unify top-level quiet infrastructure

tools: Remove redundant quiet setup

2025-02-18T19:27:43+00:00

Q is exported from Makefile.include so it is not necessary to manually set it. Reviewed-by: Jiri Olsa Signed-off-by: Charlie Jenkins Acked-by: Andrii Nakryiko Acked-by: Quentin Monnet Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Alexei Starovoitov Cc: Benjamin Tissoires Cc: Daniel Borkmann Cc: Daniel Lezcano Cc: Eduard Zingerman Cc: Hao Luo Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Kosina Cc: John Fastabend Cc: Josh Poimboeuf Cc: KP Singh Cc: Lukasz Luba Cc: Mark Rutland Cc: Martin KaFai Lau Cc: Mykola Lysenko Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Rafael J. Wysocki Cc: Shuah Khan Cc: Song Liu Cc: Stanislav Fomichev Cc: Steven Rostedt (VMware) Cc: Yonghong Song Cc: Zhang Rui Link: https://lore.kernel.org/r/20250213-quiet_tools-v3-2-07de4482a581@rivosinc.com Signed-off-by: Arnaldo Carvalho de Melo

tools/rtla: Add basic test suite

2025-01-23T17:21:45+00:00

Implement a simple TAP-based test engine in bash and a few basic tests using it, to be used to check for bugs and regressions. A new "check" target is added to the rtla Makefile that runs the test suite using the "prove" command implemented by Test::Harness. The only test format currently supported is running rtla with defined command arguments per test, checking its exit code. In case the exit code is non-zero, the output of rtla is displayed, together with the exit code. The test cases are adopted from rtla tests in the Continuous Kernel Integration (CKI) project [1] with the authors' approval. [1] https://gitlab.com/redhat/centos-stream/tests/kernel/kernel-tests/-/blob/main/rt-tests/us/rtla/ Cc: John Kacur Cc: Luis Goncalves Cc: Chang Yin Cc: Qiao Zhao Link: https://lore.kernel.org/20250120135630.802111-1-tglozar@redhat.com Signed-off-by: Tomas Glozar Signed-off-by: Steven Rostedt (Google)

rtla: Add optional dependency on libcpupower

2024-10-17T21:13:15+00:00

If libcpupower is present, set HAVE_LIBCPUPOWER_SUPPORT macro to allow features depending on libcpupower in rtla. Link: https://lore.kernel.org/20241017140914.3200454-3-tglozar@redhat.com Signed-off-by: Tomas Glozar Signed-off-by: Steven Rostedt (Google)

tools/rtla: Use tools/build makefiles to build rtla

2024-03-20T04:39:06+00:00

Use tools/build/ makefiles to build rtla, inheriting the benefits of it. For example, having a proper way to handle dependencies. rtla is built using perf infra-structure when building inside the kernel tree. At this point, rtla diverges from perf in two points: Documentation and tarball generation/build. At the documentation level, rtla is one step ahead, placing the documentation at Documentation/tools/rtla/, using the same build tools as kernel documentation. The idea is to move perf documentation to the same scheme and then share the same makefiles. rtla has a tarball target that the (old) RHEL8 uses. The tarball was kept using a simple standalone makefile for compatibility. The standalone makefile shares most of the code, e.g., flags, with regular buildings. The tarball method was set as deprecated. If necessary, we can make a rtla tarball like perf, which includes the entire tools/build. But this would also require changes in the user side (the directory structure changes, and probably the deps to build the package). Inspired on perf and objtool. Link: https://lkml.kernel.org/r/57563abf2715d22515c0c54a87cff3849eca5d52.1710519524.git.bristot@kernel.org Cc: Arnaldo Carvalho de Melo Cc: Josh Poimboeuf Cc: John Kacur Cc: Namhyung Kim Cc: Jiri Olsa Suggested-by: Linus Torvalds Signed-off-by: Daniel Bristot de Oliveira

tools/rtla: Fix Makefile compiler options for clang

2024-02-12T08:49:13+00:00

The following errors are showing up when compiling rtla with clang: $ make HOSTCC=clang CC=clang LLVM_IAS=1 [...] clang -O -g -DVERSION=\"6.8.0-rc1\" -flto=auto -ffat-lto-objects -fexceptions -fstack-protector-strong -fasynchronous-unwind-tables -fstack-clash-protection -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS -Wno-maybe-uninitialized $(pkg-config --cflags libtracefs) -c -o src/utils.o src/utils.c clang: warning: optimization flag '-ffat-lto-objects' is not supported [-Wignored-optimization-argument] warning: unknown warning option '-Wno-maybe-uninitialized'; did you mean '-Wno-uninitialized'? [-Wunknown-warning-option] 1 warning generated. clang -o rtla -ggdb src/osnoise.o src/osnoise_hist.o src/osnoise_top.o src/rtla.o src/timerlat_aa.o src/timerlat.o src/timerlat_hist.o src/timerlat_top.o src/timerlat_u.o src/trace.o src/utils.o $(pkg-config --libs libtracefs) src/osnoise.o: file not recognized: file format not recognized clang: error: linker command failed with exit code 1 (use -v to see invocation) make: *** [Makefile:110: rtla] Error 1 Solve these issues by: - removing -ffat-lto-objects and -Wno-maybe-uninitialized if using clang - informing the linker about -flto=auto Link: https://lore.kernel.org/linux-trace-kernel/567ac1b94effc228ce9a0225b9df7232a9b35b55.1707217097.git.bristot@kernel.org Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Bill Wendling Cc: Justin Stitt Fixes: 1a7b22ab15eb ("tools/rtla: Build with EXTRA_{C,LD}FLAGS") Suggested-by: Donald Zickus Signed-off-by: Daniel Bristot de Oliveira