linux/tools/perf/util/c++/Build, branch master

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

2023-08-15T19:41:48Z

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 Tested-by: Arnaldo Carvalho de Melo Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Andi Kleen Cc: Andrii Nakryiko Cc: Anshuman Khandual Cc: Athira Rajeev Cc: Brendan Gregg Cc: Carsten Haitzler Cc: Eduard Zingerman Cc: Fangrui Song Cc: He Kuang Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Kan Liang Cc: Leo Yan Cc: Madhavan Srinivasan Cc: Mark Rutland Cc: Namhyung Kim Cc: Nathan Chancellor Cc: "Naveen N. Rao" Cc: Nick Desaulniers Cc: Peter Zijlstra Cc: Ravi Bangoria Cc: Rob Herring Cc: Tiezhu Yang Cc: Tom Rix Cc: Wang Nan Cc: Wang ShaoBo Cc: Yang Jihong Cc: Yonghong Song Cc: YueHaibing Link: https://lore.kernel.org/lkml/ZNZWsAXg2px1sm2h@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf build: Add Wextra for C++ compilation

2023-07-28T22:01:17Z

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 Acked-by: James Clark Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Andrii Nakryiko Cc: Eduard Zingerman Cc: Gaosheng Cui Cc: Ingo Molnar Cc: Jiri Olsa Cc: Kan Liang Cc: Mark Rutland Cc: Namhyung Kim Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Peter Zijlstra Cc: Rob Herring Cc: Tom Rix 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

perf tools: Rename build libperf to perf

2019-02-14T18:18:08Z

Rename build libperf to perf, because it's used to build perf. The libperf build object name will be used for libperf library. Signed-off-by: Jiri Olsa Cc: Alexander Shishkin Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20190213123246.4015-4-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf clang: Add builtin clang support ant test case

2016-12-05T18:51:43Z

Add basic clang support in clang.cpp and test__clang() testcase. The first testcase checks if builtin clang is able to generate LLVM IR. tests/clang.c is a proxy. Real testcase resides in utils/c++/clang-test.cpp in c++ and exports C interface to perf test subsystem. Test result: $ perf test -v clang 51: builtin clang support : 51.1: Test builtin clang compile C source to IR : --- start --- test child forked, pid 13215 test child finished with 0 ---- end ---- Test builtin clang support subtest 0: Ok Committer note: Make sure you've enabled CLANG and LLVM builtin support by setting the LIBCLANGLLVM variable on the make command line, e.g.: make LIBCLANGLLVM=1 O=/tmp/build/perf -C tools/perf install-bin Otherwise you'll get this when trying to do the 'perf test' call above: # perf test clang 51: builtin clang support : Skip (not compiled in) # Signed-off-by: Wang Nan Tested-by: Arnaldo Carvalho de Melo Cc: Alexei Starovoitov Cc: He Kuang Cc: Jiri Olsa Cc: Joe Stringer Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/20161126070354.141764-11-wangnan0@huawei.com [ Removed "Test" from descriptions, redundant and already removed from all the other entries ] Signed-off-by: Arnaldo Carvalho de Melo