Re: [PATCH bpf-next v3 0/6] bpf trampoline support "jmp" mode

Leon Hwang
2025-11-19T02:55:43Z

On 19/11/25 10:47, Menglong Dong wrote:
> On 2025/11/19 08:28, Alexei Starovoitov wrote:
>> On Tue, Nov 18, 2025 at 4:36 AM Menglong Dong <menglong8.dong@gmail.com> wrote:
>>>
>>> As we can see above, the performance of fexit increase from 80.544M/s to
>>> 136.540M/s, and the "fmodret" increase from 78.301M/s to 159.248M/s.
>>
>> Nice! Now we're talking.
>>
>> I think arm64 CPUs have a similar RSB-like return address predictor.
>> Do we need to do something similar there?
>> The question is not targeted to you, Menglong,
>> just wondering.
>
> I did some research before, and I find that most arch
> have such RSB-like stuff. I'll have a look at the loongarch
> later(maybe after the LPC, as I'm forcing on the English practice),
> and Leon is following the arm64.

Yep, happy to take this on.

I'm reviewing the arm64 JIT code now and will experiment with possible
approaches to handle this as well.

Thanks,
Leon

>
> For the other arch, we don't have the machine, and I think
> it needs some else help.
>
> Thanks!
> Menglong Dong