linux/tools/perf/util/c++, 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 clang: Fix header include for LLVM >= 14

2022-04-22T21:39:34Z

The header TargetRegistry.h has moved in LLVM/clang 14. Committer notes: The problem as noticed when building in ubuntu:22.04: 90 98.61 ubuntu:22.04 : FAIL gcc version 11.2.0 (Ubuntu 11.2.0-19ubuntu1) util/c++/clang.cpp:23:10: fatal error: llvm/Support/TargetRegistry.h: No such file or directory 23 | #include "llvm/Support/TargetRegistry.h" | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ compilation terminated. Fixed after applying this patch. Reported-by: Arnaldo Carvalho de Melo Signed-off-by: Guilherme Amadio Tested-by: Arnaldo Carvalho de Melo Link: https://twitter.com/GuilhermeAmadio/status/1514970524232921088 Link: http://lore.kernel.org/lkml/Ylp0M/VYgHOxtcnF@gentoo.org Signed-off-by: Arnaldo Carvalho de Melo

perf test: Convert clang tests to test cases.

2021-11-13T21:11:49Z

Use null terminated array of test cases rather than the previous sub test functions. Signed-off-by: Ian Rogers Tested-by: Sohaib Mohamed Acked-by: Jiri Olsa Cc: Alexander Shishkin Cc: Brendan Higgins Cc: Daniel Latypov Cc: David Gow Cc: Ingo Molnar Cc: Jin Yao Cc: John Garry Cc: Mark Rutland Cc: Namhyung Kim Cc: Paul Clarke Cc: Peter Zijlstra Cc: Stephane Eranian Link: https://lore.kernel.org/r/20211104064208.3156807-13-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf clang: Fixes for more recent LLVM/clang

2021-11-04T12:32:00Z

The parameters to two functions and the location of a variable have changed in more recent LLVM/clang releases. Remove the unneecessary -fmessage-length and -ferror-limit flags, the former causes failures like: 58: builtin clang support : 58.1: builtin clang compile C source to IR : --- start --- test child forked, pid 279307 error: unknown argument: '-fmessage-length' 1 error generated. test child finished with -1 Tested with LLVM 6, 8, 9, 10 and 11. Reviewed-by: Fangrui Song Signed-off-by: Ian Rogers Cc: Alexander Shishkin Cc: Daniel Borkmann Cc: Ingo Molnar Cc: Jiri Olsa Cc: Leo Yan Cc: Mark Rutland Cc: Michael Petlan Cc: Namhyung Kim Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Peter Zijlstra Cc: Sedat Dilek , Cc: llvm@lists.linux.dev Signed-off-by: Arnaldo Carvalho de Melo

perf clang: Fix build with Clang 9

2020-01-14T15:02:19Z

LLVM D59377 (included in Clang 9) refactored Clang VFS construction a bit, which broke perf clang build. Let's fix it. Signed-off-by: Maciej S. Szmigiero Reviewed-by: Dennis Schridde Cc: Alexander Shishkin Cc: clang-built-linux@googlegroups.com Cc: Denis Pronin Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Naohiro Aota Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/20191228171314.946469-2-mail@maciej.szmigiero.name Signed-off-by: Arnaldo Carvalho de Melo

perf clang: Delete needless util-cxx.h header

2019-08-28T21:14:57Z

It was put in place just to make sure the 'new' C++ operator wouldn't clash with some argument name in util.h, but there is not anymore any such argument and also the reason stated for util.h to be included there was to get the __maybe_unused definition, that is in linux/compiler.h, so use that instead and nuke util-cxx.h. Cc: Adrian Hunter Cc: He Kuang Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: https://lkml.kernel.org/n/tip-1r5tvfnwiydjxhukgqs6bi11@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf clang: Remove needless extra semicolon

2019-03-06T12:47:48Z

Delete a superfluous semicolon in getBPFObjectFromModule(). Signed-off-by: Yang Wei Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Yang Wei Link: http://lkml.kernel.org/r/1551710174-3349-1-git-send-email-albin_yang@163.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: Do not use 'return std::move(something)'

2019-02-04T14:32:34Z

It prevents copy elision, generating this warning when building with fedora:rawhide's clang: clang version 7.0.1 (Fedora 7.0.1-2.fc30) Target: x86_64-unknown-linux-gnu Thread model: posix InstalledDir: /usr/bin Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-redhat-linux/9 Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/9 Selected GCC installation: /usr/bin/../lib/gcc/x86_64-redhat-linux/9 Candidate multilib: .;@m64 Candidate multilib: 32;@m32 Selected multilib: .;@m64 $ make -C tools/perf CC=clang LIBCLANGLLVM=1 util/c++/clang.cpp: In function 'std::unique_ptr > perf::getBPFObjectFromModule(llvm::Module*)': util/c++/clang.cpp:163:18: error: moving a local object in a return statement prevents copy elision [-Werror=pessimizing-move] 163 | return std::move(Buffer); | ~~~~~~~~~^~~~~~~~ util/c++/clang.cpp:163:18: note: remove 'std::move' call cc1plus: all warnings being treated as errors References: http://www.cplusplus.com/forum/general/186411/#msg908572 https://en.cppreference.com/w/cpp/language/return#Notes https://en.cppreference.com/w/cpp/language/copy_elision Cc: Adrian Hunter Cc: Jiri Olsa Cc: Luis Cláudio Gonçalves Cc: Namhyung Kim Cc: Wang Nan Link: https://lkml.kernel.org/n/tip-lehqf5x5q96l0o8myhb6blz6@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo