bpf.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
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

      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]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=87o8y7n8ia.fsf@toke.dk \
    --to=toke@redhat.com \
    --cc=andrii.nakryiko@gmail.com \
    --cc=ast@kernel.org \
    --cc=bpf@vger.kernel.org \
    --cc=brouer@redhat.com \
    --cc=daniel@iogearbox.net \
    --cc=davem@davemloft.net \
    --cc=kafai@fb.com \
    --cc=netdev@vger.kernel.org \
    --cc=songliubraving@fb.com \
    --cc=yhs@fb.com \
    --subject='Re: [PATCH bpf-next 3/3] libbpf: Add pin option to automount BPF filesystem before pinning' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).