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From:   Cong Wang <xiyou.wangcong@gmail.com>
Date:   Thu, 17 Dec 2020 13:14:14 -0800
Message-ID: <CAM_iQpXOts4YFsfaZYKiL-8u=v=0_vQ+DjML8g_JD0jPfz9kpw@mail.gmail.com>
Subject: Re: [Patch bpf-next v2 2/5] bpf: introduce timeout map
To:     Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc:     Networking <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>,
        Cong Wang <cong.wang@bytedance.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Dongdong Wang <wangdongdong.6@bytedance.com>
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On Wed, Dec 16, 2020 at 10:29 PM Cong Wang <xiyou.wangcong@gmail.com> wrote:
>
> On Wed, Dec 16, 2020 at 10:35 AM Andrii Nakryiko
> <andrii.nakryiko@gmail.com> wrote:
> > Minimize duplication of the code, no one said copy/paste all the code.
> > But memory bloat is a real problem and should be justification enough
> > to at least consider other options.
>
> Sure, I have no problem with this. The question is how do we balance?
> Is rewriting 200 lines of code to save 8 bytes of each entry acceptable?
> What about rewriting 2000 lines of code? Do people prefer to review 200
> or 2000 (or whatever number) lines of code? Or people just want a
> minimal change for easier reviews?

No worry any more. I manage to find some way to reuse the existing
members, that is lru_node. So the end result is putting gc stuff into
the union with lru_node without increasing the size of htab_elem.
And of course, without duplicating/refactoring regular htab code.

Thanks.