Re: [PATCH v3 net-next] bpf: fix bpf_perf_event_read() helper

From: Ingo Molnar
Date: Sun Oct 25 2015 - 05:21:52 EST



* Alexei Starovoitov <ast@xxxxxxxxxxxx> wrote:

> On 10/23/15 5:03 AM, Peter Zijlstra wrote:
> >So the bpf_perf_event_read() returns the count value, does this not also
> >mean that returning -EINVAL here is also 'wrong'?
> >
> >I mean, sure an actual count value that high is unlikely, but its still
> >a broken interface.
>
> Agree. that's not pretty interface. I wish I looked at it more carefully
> when it was introduced. Now it's too late to change.

So I really, really think eBPF needs to have an easy to use mechanism to phase out
old ABI components and introducing new (better) ones!

Then old crap can be de-emphasised and eventually removed, instead of having to
live with crap forever ...

Thanks,

Ingo
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