Re: Building perf with BUILD_BPF_SKEL=1 by default

From: Arnaldo Carvalho de Melo
Date: Fri Dec 03 2021 - 08:28:07 EST


Em Fri, Dec 03, 2021 at 10:10:42AM -0300, Arnaldo Carvalho de Melo escreveu:
> Hi Song,
>
> So I'm changing all my containers to build with BUILD_BPF_SKEL=1
> to then make this the default, so far older containers fail either
> because the clang available is too old, so I've added a NO_BUILD_BPF_SKEL=1
> env var to disable that in those containers and then there is this other
> case where clang is recent enough but:
>
> util/bpf_skel/bperf_leader.bpf.c:13:20: error: use of undeclared identifier 'BPF_F_PRESERVE_ELEMS'
> __uint(map_flags, BPF_F_PRESERVE_ELEMS);
>
> Because the system's /usr/include/linux/bpf.h doesn't have that
> BPF_F_PRESERVE_ELEMS enum entry.
>
> These are enums to make them available via BTF, but then I can't use
> the:
>
> #ifdef BPF_F_PRESERVE_ELEMS
> #define BPF_F_PRESERVE_ELEMS (1U << 11)
> #endif
>
> approach.
>
> But then we _have_ it in the tools/include/uapi/linux/bpf.h we ship:
>
> $ grep BPF_F_PRESERVE_ELEMS tools/include/uapi/linux/bpf.h
> BPF_F_PRESERVE_ELEMS = (1U << 11),
> $
>
> so we need to switch to using it somehow, this way we can build in more
> systems and make bperf and other BPF enabled features.
>
> From a quick look I couldn't find where to add
> $(sourcedir)/tools/include/uapi/ to the include path used to build
> util/bpf_skel/bperf_leader.bpf.c, should be easy, can you take a look?

The failure for fedora:32, which seems to be on the threshold for clang
to be considered recent enough for building skels fails differently:

clang version 10.0.1 (Fedora 10.0.1-3.fc32)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-redhat-linux/10
Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/10
Selected GCC installation: /usr/bin/../lib/gcc/x86_64-redhat-linux/10
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64
+ '[' '!' ']'
+ rm -rf /tmp/build/perf
+ mkdir /tmp/build/perf
+ make ARCH= CROSS_COMPILE= EXTRA_CFLAGS= BUILD_BPF_SKEL=1 -C tools/perf O=/tmp/build/perf
make: Entering directory '/git/perf-5.16.0-rc3/tools/perf'
BUILD: Doing 'make -j32' parallel build
HOSTCC /tmp/build/perf/fixdep.o
HOSTLD /tmp/build/perf/fixdep-in.o
LINK /tmp/build/perf/fixdep
/bin/sh: -c: line 0: syntax error near unexpected token `('
/bin/sh: -c: line 0: `expr bison (GNU Bison) 3.5 \>\= 371'
Makefile.config:997: No libbabeltrace found, disables 'perf data' CTF format support, please install libbabeltrace-dev[el]/libbabeltrace-ctf-dev

Auto-detecting system features:
... dwarf: [ on ]
... dwarf_getlocations: [ on ]
... glibc: [ on ]
... libbfd: [ on ]
... libbfd-buildid: [ on ]
... libcap: [ on ]
... libelf: [ on ]
... libnuma: [ on ]
... numa_num_possible_cpus: [ on ]
... libperl: [ on ]
... libpython: [ on ]
... libcrypto: [ on ]
... libunwind: [ on ]
... libdw-dwarf-unwind: [ on ]
... zlib: [ on ]
... lzma: [ on ]
... get_cpuid: [ on ]
... bpf: [ on ]
... libaio: [ on ]
... libzstd: [ on ]
... disassembler-four-args: [ on ]


GEN /tmp/build/perf/common-cmds.h
PERF_VERSION = 5.16.rc3.g0c338bcdfdb1
CC /tmp/build/perf/exec-cmd.o
CC /tmp/build/perf/help.o
CC /tmp/build/perf/cpu.o
CC /tmp/build/perf/pager.o
CC /tmp/build/perf/debug.o
GEN perf-archive
CC /tmp/build/perf/parse-options.o
CC /tmp/build/perf/str_error_r.o
GEN perf-with-kcore
CC /tmp/build/perf/run-command.o
CC /tmp/build/perf/sigchain.o
GEN perf-iostat
MKDIR /tmp/build/perf/fd/
MKDIR /tmp/build/perf/fs/
CC /tmp/build/perf/subcmd-config.o
MKDIR /tmp/build/perf/jvmti/
MKDIR /tmp/build/perf/fs/
MKDIR /tmp/build/perf/jvmti/
CC /tmp/build/perf/dlfilters/dlfilter-test-api-v0.o
CC /tmp/build/perf/dlfilters/dlfilter-show-cycles.o
MKDIR /tmp/build/perf/jvmti/
CC /tmp/build/perf/fd/array.o
MKDIR /tmp/build/perf/fs/
CC /tmp/build/perf/fs/fs.o
MKDIR /tmp/build/perf/jvmti/
MKDIR /tmp/build/perf/pmu-events/
CC /tmp/build/perf/event-parse.o
MKDIR /tmp/build/perf/pmu-events/
CC /tmp/build/perf/jvmti/libjvmti.o
CC /tmp/build/perf/jvmti/jvmti_agent.o
CC /tmp/build/perf/fs/tracing_path.o
CC /tmp/build/perf/jvmti/libstring.o
CC /tmp/build/perf/fs/cgroup.o
HOSTCC /tmp/build/perf/pmu-events/json.o
CC /tmp/build/perf/jvmti/libctype.o
CC /tmp/build/perf/core.o
HOSTCC /tmp/build/perf/pmu-events/jsmn.o
MKDIR /tmp/build/perf/pmu-events/
HOSTCC /tmp/build/perf/pmu-events/jevents.o
CC /tmp/build/perf/cpumap.o
CC /tmp/build/perf/plugin_jbd2.o
CC /tmp/build/perf/plugin_hrtimer.o
CC /tmp/build/perf/plugin_kmem.o
CC /tmp/build/perf/threadmap.o
CC /tmp/build/perf/plugin_kvm.o
CC /tmp/build/perf/evsel.o
CC /tmp/build/perf/plugin_mac80211.o
LINK /tmp/build/perf/dlfilters/dlfilter-show-cycles.so
CC /tmp/build/perf/plugin_sched_switch.o
make[3]: *** No rule to make target 'kernelversion'. Stop.
CC /tmp/build/perf/plugin_function.o
LD /tmp/build/perf/fd/libapi-in.o
CC /tmp/build/perf/event-plugin.o
GEN /tmp/build/perf/libbpf/bpf_helper_defs.h
CC /tmp/build/perf/plugin_futex.o
CC /tmp/build/perf/plugin_xen.o
CC /tmp/build/perf/plugin_scsi.o
CC /tmp/build/perf/evlist.o
INSTALL /tmp/build/perf/libbpf/include/bpf/bpf.h
LD /tmp/build/perf/plugin_jbd2-in.o
CC /tmp/build/perf/plugin_cfg80211.o
INSTALL /tmp/build/perf/libbpf/include/bpf/libbpf.h
LD /tmp/build/perf/plugin_hrtimer-in.o
LD /tmp/build/perf/fs/libapi-in.o
LD /tmp/build/perf/plugin_kmem-in.o
CC /tmp/build/perf/plugin_tlb.o
LINK /tmp/build/perf/dlfilters/dlfilter-test-api-v0.so
CC /tmp/build/perf/mmap.o
CC /tmp/build/perf/zalloc.o
LINK /tmp/build/perf/plugin_jbd2.so
LINK /tmp/build/perf/plugin_hrtimer.so
INSTALL /tmp/build/perf/libbpf/include/bpf/btf.h
CC /tmp/build/perf/xyarray.o
CC /tmp/build/perf/trace-seq.o
LD /tmp/build/perf/plugin_mac80211-in.o
LD /tmp/build/perf/libapi-in.o
LD /tmp/build/perf/plugin_kvm-in.o
CC /tmp/build/perf/parse-filter.o
CC /tmp/build/perf/parse-utils.o
LD /tmp/build/perf/plugin_sched_switch-in.o
CC /tmp/build/perf/kbuffer-parse.o
CC /tmp/build/perf/tep_strerror.o
HOSTLD /tmp/build/perf/pmu-events/jevents-in.o
INSTALL /tmp/build/perf/libbpf/include/bpf/libbpf_common.h
INSTALL /tmp/build/perf/libbpf/include/bpf/libbpf_legacy.h
CC /tmp/build/perf/event-parse-api.o
INSTALL /tmp/build/perf/libbpf/include/bpf/xsk.h
INSTALL /tmp/build/perf/libbpf/include/bpf/bpf_helpers.h
AR /tmp/build/perf/libapi.a
LD /tmp/build/perf/plugin_function-in.o
INSTALL /tmp/build/perf/libbpf/include/bpf/bpf_tracing.h
LINK /tmp/build/perf/plugin_kmem.so
LINK /tmp/build/perf/plugin_mac80211.so
LINK /tmp/build/perf/plugin_kvm.so
LD /tmp/build/perf/plugin_xen-in.o
LINK /tmp/build/perf/plugin_sched_switch.so
LD /tmp/build/perf/plugin_cfg80211-in.o
CC /tmp/build/perf/lib.o
INSTALL /tmp/build/perf/libbpf/include/bpf/bpf_endian.h
LD /tmp/build/perf/plugin_futex-in.o
LD /tmp/build/perf/plugin_scsi-in.o
INSTALL /tmp/build/perf/libbpf/include/bpf/bpf_core_read.h
LINK /tmp/build/perf/pmu-events/jevents
LD /tmp/build/perf/plugin_tlb-in.o
LINK /tmp/build/perf/plugin_function.so
LINK /tmp/build/perf/plugin_xen.so
INSTALL /tmp/build/perf/libbpf/include/bpf/skel_internal.h
LINK /tmp/build/perf/plugin_cfg80211.so
INSTALL /tmp/build/perf/libbpf/include/bpf/libbpf_version.h
LINK /tmp/build/perf/plugin_futex.so
INSTALL /tmp/build/perf/libbpf/include/bpf/bpf_helper_defs.h
LINK /tmp/build/perf/plugin_scsi.so
LD /tmp/build/perf/jvmti/jvmti-in.o
LINK /tmp/build/perf/plugin_tlb.so
MKDIR /tmp/build/perf/libbpf/staticobjs/
MKDIR /tmp/build/perf/libbpf/staticobjs/
MKDIR /tmp/build/perf/libbpf/staticobjs/
MKDIR /tmp/build/perf/libbpf/staticobjs/
MKDIR /tmp/build/perf/libbpf/staticobjs/
LD /tmp/build/perf/libsubcmd-in.o
MKDIR /tmp/build/perf/libbpf/staticobjs/
MKDIR /tmp/build/perf/libbpf/staticobjs/
MKDIR /tmp/build/perf/libbpf/staticobjs/
MKDIR /tmp/build/perf/libbpf/staticobjs/
CC /tmp/build/perf/libbpf/staticobjs/xsk.o
CC /tmp/build/perf/libbpf/staticobjs/libbpf.o
LINK /tmp/build/perf/libperf-jvmti.so
CC /tmp/build/perf/libbpf/staticobjs/bpf.o
CC /tmp/build/perf/libbpf/staticobjs/nlattr.o
CC /tmp/build/perf/libbpf/staticobjs/btf.o
CC /tmp/build/perf/libbpf/staticobjs/libbpf_errno.o
CC /tmp/build/perf/libbpf/staticobjs/hashmap.o
CC /tmp/build/perf/libbpf/staticobjs/str_error.o
CC /tmp/build/perf/libbpf/staticobjs/netlink.o
CC /tmp/build/perf/libbpf/staticobjs/btf_dump.o
CC /tmp/build/perf/libbpf/staticobjs/bpf_prog_linfo.o
CC /tmp/build/perf/libbpf/staticobjs/libbpf_probes.o
CC /tmp/build/perf/libbpf/staticobjs/ringbuf.o
CC /tmp/build/perf/libbpf/staticobjs/strset.o
GEN /tmp/build/perf/libtraceevent-dynamic-list
CC /tmp/build/perf/libbpf/staticobjs/linker.o
CC /tmp/build/perf/libbpf/staticobjs/gen_loader.o
CC /tmp/build/perf/libbpf/staticobjs/relo_core.o
AR /tmp/build/perf/libsubcmd.a
LD /tmp/build/perf/libtraceevent-in.o
GEN /tmp/build/perf/pmu-events/pmu-events.c
LINK /tmp/build/perf/libtraceevent.a
LD /tmp/build/perf/libperf-in.o
AR /tmp/build/perf/libperf.a
GEN /tmp/build/perf/python/perf.so
CC /tmp/build/perf/pmu-events/pmu-events.o

Auto-detecting system features:
... libbfd: [ on ]
... disassembler-four-args: [ on ]
... zlib: [ on ]
... libcap: [ on ]
... clang-bpf-co-re: [ on ]


MKDIR /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf//include/bpf
MKDIR /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/
MKDIR /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/
INSTALL /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf//include/bpf/hashmap.h
GEN /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/bpf_helper_defs.h
INSTALL /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf//include/bpf/bpf.h
INSTALL /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf//include/bpf/libbpf.h
INSTALL /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf//include/bpf/btf.h
INSTALL /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf//include/bpf/libbpf_common.h
INSTALL /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf//include/bpf/libbpf_legacy.h
INSTALL /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf//include/bpf/xsk.h
INSTALL /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf//include/bpf/bpf_helpers.h
INSTALL /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf//include/bpf/bpf_tracing.h
INSTALL /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf//include/bpf/bpf_endian.h
INSTALL /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf//include/bpf/bpf_core_read.h
INSTALL /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf//include/bpf/skel_internal.h
INSTALL /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf//include/bpf/libbpf_version.h
INSTALL /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf//include/bpf/bpf_helper_defs.h
MKDIR /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/
MKDIR /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/
MKDIR /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/
MKDIR /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/
MKDIR /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/
MKDIR /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/
MKDIR /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/
MKDIR /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/
MKDIR /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/
MKDIR /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/
MKDIR /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/
CC /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/btf_dump.o
CC /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/libbpf.o
CC /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/bpf.o
CC /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/nlattr.o
CC /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/btf.o
CC /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/ringbuf.o
CC /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/libbpf_errno.o
CC /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/str_error.o
CC /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/netlink.o
CC /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/bpf_prog_linfo.o
CC /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/strset.o
CC /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/libbpf_probes.o
CC /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/xsk.o
CC /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/hashmap.o
CC /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/linker.o
CC /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/gen_loader.o
CC /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/relo_core.o
LD /tmp/build/perf/pmu-events/pmu-events-in.o
LD /tmp/build/perf/libbpf/staticobjs/libbpf-in.o
LINK /tmp/build/perf/libbpf/libbpf.a
LD /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/staticobjs/libbpf-in.o
LINK /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/libbpf/libbpf.a
CC /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/common.o
CC /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/main.o
CC /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/json_writer.o
CC /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/gen.o
CC /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/xlated_dumper.o
CC /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/btf.o
CC /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/btf_dumper.o
CC /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/disasm.o
LINK /tmp/build/perf/util/bpf_skel/.tmp//bootstrap/bpftool
GEN /tmp/build/perf/util/bpf_skel/vmlinux.h
CLANG /tmp/build/perf/util/bpf_skel/.tmp/bpf_prog_profiler.bpf.o
CLANG /tmp/build/perf/util/bpf_skel/.tmp/bperf_leader.bpf.o
CLANG /tmp/build/perf/util/bpf_skel/.tmp/bperf_follower.bpf.o
CLANG /tmp/build/perf/util/bpf_skel/.tmp/bperf_cgroup.bpf.o
GENSKEL /tmp/build/perf/util/bpf_skel/bpf_prog_profiler.skel.h
GENSKEL /tmp/build/perf/util/bpf_skel/bperf_leader.skel.h
libbpf: elf: skipping unrecognized data section(9) .eh_frame
libbpf: elf: skipping relo section(15) .rel.eh_frame for section(9) .eh_frame
libbpf: elf: skipping unrecognized data section(7) .eh_frame
libbpf: elf: skipping relo section(12) .rel.eh_frame for section(7) .eh_frame
libbpf: map 'prev_readings': unexpected def kind var.
Error: failed to open BPF object file: Invalid argument
make[2]: *** [Makefile.perf:1076: /tmp/build/perf/util/bpf_skel/bperf_leader.skel.h] Error 255
make[2]: *** Waiting for unfinished jobs....
make[1]: *** [Makefile.perf:240: sub-make] Error 2
make: *** [Makefile:70: all] Error 2
make: Leaving directory '/git/perf-5.16.0-rc3/tools/perf'
+ exit 1
[perfbuilder@five 32]$