From: "Toke Høiland-Jørgensen" <toke@redhat.com>
To: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>,
Alexei Starovoitov <ast@kernel.org>,
Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
Yonghong Song <yhs@fb.com>,
Jesper Dangaard Brouer <brouer@redhat.com>,
David Miller <davem@davemloft.net>,
Networking <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>
Subject: Re: [PATCH bpf-next 3/3] libbpf: Add pin option to automount BPF filesystem before pinning
Date: Wed, 23 Oct 2019 10:58:21 +0200 [thread overview]
Message-ID: <87o8y7n8ia.fsf@toke.dk> (raw)
In-Reply-To: <CAEf4Bzap3oMPnGJQAsoV-g77ux0FdELiJpvpxn9_zadVnHYdSA@mail.gmail.com>
Andrii Nakryiko <andrii.nakryiko@gmail.com> writes:
> On Tue, Oct 22, 2019 at 12:04 PM Toke Høiland-Jørgensen <toke@redhat.com> wrote:
>>
>> Andrii Nakryiko <andrii.nakryiko@gmail.com> writes:
>>
>> > On Tue, Oct 22, 2019 at 9:08 AM Toke Høiland-Jørgensen <toke@redhat.com> wrote:
>> >>
>> >> From: Toke Høiland-Jørgensen <toke@redhat.com>
>> >>
>> >> While the current map pinning functions will check whether the pin path is
>> >> contained on a BPF filesystem, it does not offer any options to mount the
>> >> file system if it doesn't exist. Since we now have pinning options, add a
>> >> new one to automount a BPF filesystem at the pinning path if that is not
>> >
>> > Next thing we'll be adding extra options to mount BPF FS... Can we
>> > leave the task of auto-mounting BPF FS to tools/applications?
>>
>> Well, there was a reason I put this into a separate patch: I wasn't sure
>> it really fit here. My reasoning is the following: If we end up with a
>> default auto-pinning that works really well, people are going to just
>> use that. And end up really confused when bpffs is not mounted. And it
>> seems kinda silly to make every application re-implement the same mount
>> check and logic.
>>
>> Or to put it another way: If we agree that the reasonable default thing
>> is to just pin things in /sys/fs/bpf, let's make it as easy as possible
>> for applications to do that right.
>>
>
> This reminds me the setrlimit() issue, though.
Heh, yeah. I personally consider the rlimit issue one of the top
usability issues with BPF :/
> And we decided that library shouldn't be manipulating global resources
> on behalf of users. I think this is a similar one.
Hmm, that's a fair point, actually. I do get twitchy watching most
applications just blindly setting rlimit to unlimited before they try to
load BPF programs...
I think I'll just drop this patch for now :)
-Toke
prev parent reply other threads:[~2019-10-23 8:58 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-22 15:04 [PATCH bpf-next 0/3] libbpf: Support pinning of maps using 'pinning' BTF attribute Toke Høiland-Jørgensen
2019-10-22 15:04 ` [PATCH bpf-next 1/3] libbpf: Store map pin path in struct bpf_map Toke Høiland-Jørgensen
2019-10-22 17:37 ` Andrii Nakryiko
2019-10-22 18:13 ` Toke Høiland-Jørgensen
2019-10-22 18:23 ` Andrii Nakryiko
2019-10-22 18:45 ` Toke Høiland-Jørgensen
2019-10-22 18:49 ` Andrii Nakryiko
2019-10-22 19:06 ` Toke Høiland-Jørgensen
2019-10-23 4:43 ` Andrii Nakryiko
2019-10-22 15:04 ` [PATCH bpf-next 2/3] libbpf: Support configurable pinning of maps from BTF annotations Toke Høiland-Jørgensen
2019-10-22 18:20 ` Andrii Nakryiko
2019-10-22 18:57 ` Toke Høiland-Jørgensen
2019-10-23 4:40 ` Andrii Nakryiko
2019-10-23 8:53 ` Toke Høiland-Jørgensen
2019-10-23 12:30 ` Daniel Borkmann
2019-10-23 13:05 ` Toke Høiland-Jørgensen
2019-10-22 15:04 ` [PATCH bpf-next 3/3] libbpf: Add pin option to automount BPF filesystem before pinning Toke Høiland-Jørgensen
2019-10-22 18:28 ` Andrii Nakryiko
2019-10-22 19:04 ` Toke Høiland-Jørgensen
2019-10-23 4:58 ` Andrii Nakryiko
2019-10-23 8:58 ` Toke Høiland-Jørgensen [this message]
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