Re: [bpf-next 00/10] samples/bpf: modernize BPF functionality test programs

["Toke Høiland-Jørgensen" <toke@kernel.org>]

Daniel Borkmann <daniel@iogearbox.net> writes:

> On 1/16/23 2:35 PM, Toke Høiland-Jørgensen wrote:
>> "Daniel T. Lee" <danieltimlee@gmail.com> writes:
>>> On Mon, Jan 16, 2023 at 6:38 AM Alexei Starovoitov
>>> <alexei.starovoitov@gmail.com> wrote:
>>>> On Sat, Jan 14, 2023 at 11:16 PM Daniel T. Lee <danieltimlee@gmail.com> wrote:
>>>>>
>>>>> Currently, there are many programs under samples/bpf to test the
>>>>> various functionality of BPF that have been developed for a long time.
>>>>> However, the kernel (BPF) has changed a lot compared to the 2016 when
>>>>> some of these test programs were first introduced.
>>>>>
>>>>> Therefore, some of these programs use the deprecated function of BPF,
>>>>> and some programs no longer work normally due to changes in the API.
>>>>>
>>>>> To list some of the kernel changes that this patch set is focusing on,
>>>>> - legacy BPF map declaration syntax support had been dropped [1]
>>>>> - bpf_trace_printk() always append newline at the end [2]
>>>>> - deprecated styled BPF section header (bpf_load style) [3]
>>>>> - urandom_read tracepoint is removed (used for testing overhead) [4]
>>>>> - ping sends packet with SOCK_DGRAM instead of SOCK_RAW [5]*
>>>>> - use "vmlinux.h" instead of including individual headers
>>>>>
>>>>> In addition to this, this patchset tries to modernize the existing
>>>>> testing scripts a bit. And for network-related testing programs,
>>>>> a separate header file was created and applied. (To use the
>>>>> Endianness conversion function from xdp_sample and bunch of constants)
>>>>
>>>> Nice set of cleanups. Applied.
>>>> As a follow up could you convert some of them to proper selftests/bpf ?
>>>> Unfortunately samples/bpf will keep bit rotting despite your herculean efforts.
>>>
>>> I really appreciate for your compliment!
>>> I'll try to convert the existing sample to selftest in the next patch.
>
> This would be awesome, thanks a lot Daniel!
>
>> Maybe this is a good time to mention that we recently ported some of the
>> XDP utilities from samples/bpf to xdp-tools, in the form of the
>> 'xdp-bench' utility:
>> https://github.com/xdp-project/xdp-tools/tree/master/xdp-bench
>> 
>> It's basically a combination of all the xdp_redirect* samples, but also
>> includes the functionality from the xdp_rxq_info sample program (i.e.,
>> the ability to monitor RXQs and use other return codes).
>> 
>> I'm planning to submit a patch to remove those utilities from
>> samples/bpf after we tag the next release of xdp-tools (have one or two
>> outstanding issues to clear before we do that), but wanted to give you a
>> head's up so you don't spend any time on those particular utilities when
>> you're cleaning up samples :)
>
> Nice! Once we're through with most relevant ones from samples/bpf, it would
> be great to only have a readme in that dir (and that's really all) with pointers
> for developers on how to get started.. including BPF selftests, xdp tools, links
> to ebpf.io/applications and ebpf.io/infrastructure, etc where more resources
> can be found, essentially a small getting started doc for BPF devs.

Yeah, good point! Will keep that in mind :)

-Toke