netdev - Re: [PATCH net-next] x86: bpf_jit: small optimization in emit_bpf_tail

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Message-ID: <59A80308.307@iogearbox.net>
Date:   Thu, 31 Aug 2017 14:37:28 +0200
From:   Daniel Borkmann <daniel@...earbox.net>
To:     Eric Dumazet <eric.dumazet@...il.com>,
        David Miller <davem@...emloft.net>
CC:     netdev <netdev@...r.kernel.org>,
        Alexei Starovoitov <ast@...nel.org>
Subject: Re: [PATCH net-next] x86: bpf_jit: small optimization in emit_bpf_tail_call()

On 08/31/2017 01:53 PM, Eric Dumazet wrote:
> From: Eric Dumazet <edumazet@...gle.com>
>
> Saves 4 bytes replacing following instructions :
>
> lea rax, [rsi + rdx * 8 + offsetof(...)]
> mov rax, qword ptr [rax]
> cmp rax, 0
>
> by :
>
> mov rax, [rsi + rdx * 8 + offsetof(...)]
> test rax, rax
>
> Signed-off-by: Eric Dumazet <edumazet@...gle.com>
> Cc: Alexei Starovoitov <ast@...nel.org>
> Cc: Daniel Borkmann <daniel@...earbox.net>

LGTM, thanks Eric!

Acked-by: Daniel Borkmann <daniel@...earbox.net>