On Sun, Feb 23, 2020 at 6:52 PM <ethercflow@...> wrote:

[Edited Message Follows]

I tried to run CO-RE version's runqslower failed, the error info:

libbpf: sched_wakeup is not found in vmlinux BTF
libbpf: failed to load object 'runqslower_bpf'
libbpf: failed to load BPF skeleton 'runqslower_bpf': -2
failed to load BPF object: -2

ENV

clang version 10.0.0-+rc2-1
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin


Linux Kernel: 5.6.0-rc2+ (commit 8eece07c011f88da0ccf4127fca9a4e4faaf58ae)

CONFIG_CGROUP_BPF=y
CONFIG_BPF=y
CONFIG_BPF_SYSCALL=y
CONFIG_ARCH_WANT_DEFAULT_BPF_JIT=y
CONFIG_BPF_JIT_ALWAYS_ON=y
CONFIG_BPF_JIT_DEFAULT_ON=y
CONFIG_IPV6_SEG6_BPF=y
CONFIG_NETFILTER_XT_MATCH_BPF=m
CONFIG_BPFILTER=y
CONFIG_BPFILTER_UMH=m
CONFIG_NET_CLS_BPF=m
CONFIG_NET_ACT_BPF=m
CONFIG_BPF_JIT=y
CONFIG_BPF_STREAM_PARSER=y
CONFIG_LWTUNNEL_BPF=y
CONFIG_HAVE_EBPF_JIT=y
CONFIG_BPF_EVENTS=y
CONFIG_BPF_KPROBE_OVERRIDE=y
CONFIG_TEST_BPF=m


CONFIG_VIDEO_SONY_BTF_MPX=m
CONFIG_DEBUG_INFO_BTF=y


With gdb's help, I found the `btf__find_by_name_kind` return -ENOENT.
I printed all name: https://transfer.sh/ANKNs/log and found btf_trace_sched_wakeup doesn't exist.

Hi!

runqslower expects that kernel was built with BTF type info (which is
enabled by CONFIG_DEBUG_INFO_BTF=y Kconfig option). Can you please
re-build your kernel with BTF enabled
and try again?