On 3/25/20 10:26 PM, Liu Yiding wrote:

Hi, Andrii.

I noticed you had added runqslower tool to tools/bpf, so drop this problem to you.

Now i failed to run bpf tests since i can't build runqslower.

Testing env: "Debian GNU/Linux 9 (stretch)"

kernel: 5.6.0-rc5

gcc: gcc 6.3

clang: clang-11.

Description: Build runqslower failed due to build error "incomplete type" and libbpf show unsupported BTF_KIND:7.

Whole build log please see the attatchment.

Error info

root@vm-snb-144 ~/linus/tools/bpf# make

Auto-detecting system features:
...                        libbfd: [ on  ]
...        disassembler-four-args: [ OFF ]

[snip]

   INSTALL  bpftool
   LINK     bpf_asm
   GEN      vmlinux.h
libbpf: unsupported BTF_KIND:7    (Many unsupported errors)
libbpf: unsupported BTF_KIND:7
libbpf: unsupported BTF_KIND:7

Would you be able to share BTF of vmlinux that is used to generate vmlinux.h? Please run in verbose mode: `make V=1` and search for `bpftool btf dump file` command. It should point either to /sys/kernel/btf/vmlinux or some other location, depending on how things are set up on your side.

If it's /sys/kernel/btf/vmlinux, you can just `cat /sys/kernel/btf/vmlinux > my_btf.bin`. If it's some other file, easiest would be to just share that file. If not, it's possible to extract .BTF ELF section, let me know if you need help with that.

[snip]

(Many incomplete type errors)

.output/vmlinux.h:8401:18: error: field has incomplete type 'struct idt_bits'         struct idt_bits bits;                         ^ .output/vmlinux.h:8396:8: note: forward declaration of 'struct idt_bits' struct idt_bits;        ^ .output/vmlinux.h:8598:21: error: field has incomplete type 'struct trace_entry'         struct trace_entry ent;                            ^ .output/vmlinux.h:8595:8: note: forward declaration of 'struct trace_entry' struct trace_entry;        ^ .output/vmlinux.h:9006:25: error: array has incomplete element type 'struct cyc2ns_data'         struct cyc2ns_data data[2];                                ^ .output/vmlinux.h:3669:8: note: forward declaration of 'struct cyc2ns_data' struct cyc2ns_data;        ^ fatal error: too many errors emitted, stopping now [-ferror-limit=] 20 errors generated. Makefile:56: recipe for target '.output/runqslower.bpf.o' failed make[1]: *** [.output/runqslower.bpf.o] Error 1 Makefile:119: recipe for target 'runqslower' failed make: *** [runqslower] Error 2