Re: [PATCH bpf-next v3 0/4] xdp: recycle Page Pool backed skbs built from XDP frames

[Alexei Starovoitov]

On Tue, Mar 14, 2023 at 4:58 AM Alexander Lobakin
<aleksander.lobakin@xxxxxxxxx> wrote:
>
>   All error logs:
>   libbpf: prog 'trace_virtqueue_add_sgs': BPF program load failed: Bad
> address
>   libbpf: prog 'trace_virtqueue_add_sgs': -- BEGIN PROG LOAD LOG --
>   The sequence of 8193 jumps is too complex.
>   verification time 77808 usec
>   stack depth 64
>   processed 156616 insns (limit 1000000) max_states_per_insn 8
> total_states 1754 peak_states 1712 mark_read 12
>   -- END PROG LOAD LOG --
>   libbpf: prog 'trace_virtqueue_add_sgs': failed to load: -14
>   libbpf: failed to load object 'loop6.bpf.o'
>   scale_test:FAIL:expect_success unexpected error: -14 (errno 14)
>   #257     verif_scale_loop6:FAIL
>   Summary: 288/1766 PASSED, 21 SKIPPED, 1 FAILED
>
> So, xdp_do_redirect, which was previously failing, now works fine. OTOH,
> "verif_scale_loop6" now fails, but from what I understand from the log,
> it has nothing with the series ("8193 jumps is too complex" -- I don't
> even touch program-related stuff). I don't know what's the reason of it
> failing, can it be some CI issues or maybe some recent commits?

Yeah. It's an issue with the latest clang.
We don't have a workaround for this yet.
It's not a blocker for your patchset.
We didn't have time to look at it closely.