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References: <20220424051022.2619648-1-asmadeus@codewreck.org> <20220424051022.2619648-4-asmadeus@codewreck.org>
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From:   Quentin Monnet <quentin@isovalent.com>
Date:   Mon, 25 Apr 2022 22:24:37 +0100
Message-ID: <CACdoK4LH3b-n3j_9r4hbgAus1UiJkfMBOMxboTzSVWbqi+j4wg@mail.gmail.com>
Subject: Re: [PATCH 3/4] tools/bpf: musl compat: replace nftw with FTW_ACTIONRETVAL
To:     Dominique Martinet <asmadeus@codewreck.org>
Cc:     bpf <bpf@vger.kernel.org>, Networking <netdev@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>,
        KP Singh <kpsingh@kernel.org>,
        John Fastabend <john.fastabend@gmail.com>,
        Yonghong Song <yhs@fb.com>, Song Liu <songliubraving@fb.com>,
        Martin KaFai Lau <kafai@fb.com>,
        Andrii Nakryiko <andrii@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Alexei Starovoitov <ast@kernel.org>
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On Sun, 24 Apr 2022 at 06:11, Dominique Martinet <asmadeus@codewreck.org> wrote:
>
> musl nftw implementation does not support FTW_ACTIONRETVAL.
>
> There have been multiple attempts at pushing the feature in musl
> upstream but it has been refused or ignored all the times:
> https://www.openwall.com/lists/musl/2021/03/26/1
> https://www.openwall.com/lists/musl/2022/01/22/1
>
> In this case we only care about /proc/<pid>/fd/<fd>, so it's not
> too difficult to reimplement directly instead, and the new
> implementation makes 'bpftool perf' slightly faster because it doesn't
> needlessly stat/readdir unneeded directories (54ms -> 13ms on my machine)
>
> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>

Acked-by: Quentin Monnet <quentin@isovalent.com>