From: Kumar Kartikeya Dwivedi <memxor@gmail.com>
To: Cong Wang <xiyou.wangcong@gmail.com>
Cc: bpf <bpf@vger.kernel.org>, "Alexei Starovoitov" <ast@kernel.org>,
"Daniel Borkmann" <daniel@iogearbox.net>,
"Andrii Nakryiko" <andrii@kernel.org>,
"Martin KaFai Lau" <kafai@fb.com>,
"Song Liu" <songliubraving@fb.com>, "Yonghong Song" <yhs@fb.com>,
"John Fastabend" <john.fastabend@gmail.com>,
"KP Singh" <kpsingh@kernel.org>,
"Jamal Hadi Salim" <jhs@mojatatu.com>,
"Vlad Buslov" <vladbu@nvidia.com>,
"Jiri Pirko" <jiri@resnulli.us>,
"David S. Miller" <davem@davemloft.net>,
"Jakub Kicinski" <kuba@kernel.org>,
"Joe Stringer" <joe@cilium.io>,
"Quentin Monnet" <quentin@isovalent.com>,
"Jesper Dangaard Brouer" <brouer@redhat.com>,
"Toke Høiland-Jørgensen" <toke@redhat.com>,
"Linux Kernel Network Developers" <netdev@vger.kernel.org>
Subject: Re: [PATCH RFC bpf-next 0/7] Add bpf_link based TC-BPF API
Date: Sun, 13 Jun 2021 08:38:57 +0530 [thread overview]
Message-ID: <20210613030857.72bxw56bv6rwznfk@apollo> (raw)
In-Reply-To: <CAM_iQpXFmsWhMA-RO2j5Ph5Ak8yJgUVBppGj2_5NS3BuyjkvzQ@mail.gmail.com>
On Fri, Jun 11, 2021 at 07:30:49AM IST, Cong Wang wrote:
> I see why you are creating TC filters now, because you are trying to
> force the lifetime of a bpf target to align with the bpf program itself.
> The deeper reason seems to be that a cls_bpf filter looks so small
> that it appears to you that it has nothing but a bpf_prog, right?
>
Just to clarify on this further, BPF program still has its own lifetime, link
takes a reference, and the filter still takes a reference on it (since it
assumes ownership, so it was easier that way).
When releasing the bpf_link if the prog pointer is set, we also detach the TC
filter (which releases its reference on the prog). The link on destruction
releases its reference. So the rest of refcount will depend on userspace
holding/pinning the fd or not.
--
Kartikeya
prev parent reply other threads:[~2021-06-13 3:10 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-28 19:59 [PATCH RFC bpf-next 0/7] Add bpf_link based TC-BPF API Kumar Kartikeya Dwivedi
2021-05-28 19:59 ` [PATCH RFC bpf-next 1/7] net: sched: refactor cls_bpf creation code Kumar Kartikeya Dwivedi
2021-05-28 19:59 ` [PATCH RFC bpf-next 2/7] bpf: export bpf_link functions for modules Kumar Kartikeya Dwivedi
2021-05-28 19:59 ` [PATCH RFC bpf-next 3/7] net: sched: add bpf_link API for bpf classifier Kumar Kartikeya Dwivedi
2021-06-02 20:56 ` Andrii Nakryiko
2021-05-28 19:59 ` [PATCH RFC bpf-next 4/7] net: sched: add lightweight update path for cls_bpf Kumar Kartikeya Dwivedi
2021-05-28 19:59 ` [PATCH RFC bpf-next 5/7] tools: bpf.h: sync with kernel sources Kumar Kartikeya Dwivedi
2021-05-28 19:59 ` [PATCH RFC bpf-next 6/7] libbpf: add bpf_link based TC-BPF management API Kumar Kartikeya Dwivedi
2021-06-02 21:03 ` Andrii Nakryiko
2021-05-28 19:59 ` [PATCH RFC bpf-next 7/7] libbpf: add selftest for " Kumar Kartikeya Dwivedi
2021-06-02 21:09 ` [PATCH RFC bpf-next 0/7] Add bpf_link based TC-BPF API Andrii Nakryiko
2021-06-02 21:45 ` Kumar Kartikeya Dwivedi
2021-06-02 23:50 ` Alexei Starovoitov
2021-06-04 6:43 ` Kumar Kartikeya Dwivedi
2021-06-06 23:37 ` Cong Wang
2021-06-07 3:37 ` Kumar Kartikeya Dwivedi
2021-06-07 5:18 ` Cong Wang
2021-06-07 6:07 ` Kumar Kartikeya Dwivedi
2021-06-08 2:00 ` Cong Wang
2021-06-08 7:19 ` Kumar Kartikeya Dwivedi
2021-06-08 15:39 ` Alexei Starovoitov
2021-06-11 2:10 ` Cong Wang
2021-06-11 2:00 ` Cong Wang
2021-06-13 2:53 ` Kumar Kartikeya Dwivedi
2021-06-13 20:27 ` Jamal Hadi Salim
2021-06-13 20:34 ` Kumar Kartikeya Dwivedi
2021-06-13 21:10 ` Jamal Hadi Salim
2021-06-14 13:03 ` Marcelo Ricardo Leitner
2021-06-15 23:07 ` Daniel Borkmann
2021-06-16 14:40 ` Jamal Hadi Salim
2021-06-16 15:32 ` Kumar Kartikeya Dwivedi
2021-06-16 16:00 ` Daniel Borkmann
2021-06-18 11:40 ` Jamal Hadi Salim
2021-06-18 14:38 ` Alexei Starovoitov
2021-06-18 14:50 ` Jamal Hadi Salim
2021-06-18 16:23 ` Alexei Starovoitov
2021-06-18 16:41 ` Jamal Hadi Salim
2021-06-18 22:42 ` Daniel Borkmann
2021-06-21 13:55 ` Jamal Hadi Salim
2021-06-15 4:33 ` Cong Wang
2021-06-15 11:54 ` Toke Høiland-Jørgensen
2021-06-15 23:44 ` Daniel Borkmann
2021-06-16 12:03 ` Toke Høiland-Jørgensen
2021-06-16 15:33 ` Jamal Hadi Salim
2021-06-13 3:08 ` Kumar Kartikeya Dwivedi [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=20210613030857.72bxw56bv6rwznfk@apollo \
--to=memxor@gmail.com \
--cc=andrii@kernel.org \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=brouer@redhat.com \
--cc=daniel@iogearbox.net \
--cc=davem@davemloft.net \
--cc=jhs@mojatatu.com \
--cc=jiri@resnulli.us \
--cc=joe@cilium.io \
--cc=john.fastabend@gmail.com \
--cc=kafai@fb.com \
--cc=kpsingh@kernel.org \
--cc=kuba@kernel.org \
--cc=netdev@vger.kernel.org \
--cc=quentin@isovalent.com \
--cc=songliubraving@fb.com \
--cc=toke@redhat.com \
--cc=vladbu@nvidia.com \
--cc=xiyou.wangcong@gmail.com \
--cc=yhs@fb.com \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox