From: Masami Hiramatsu <mhiramat@kernel.org>
To: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Jiri Olsa <olsajiri@gmail.com>,
Alexei Starovoitov <alexei.starovoitov@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
Jiri Olsa <jolsa@redhat.com>, Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Network Development <netdev@vger.kernel.org>,
bpf <bpf@vger.kernel.org>, lkml <linux-kernel@vger.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@chromium.org>, Oleg Nesterov <oleg@redhat.com>
Subject: Re: [PATCH 0/8] bpf: Add fprobe link
Date: Fri, 18 Feb 2022 13:07:27 +0900 [thread overview]
Message-ID: <20220218130727.51db96861c3e1c79b45daafb@kernel.org> (raw)
In-Reply-To: <CAEf4BzYxcSCae=sF3EKNUtLDCZhkhHkd88CEBt4bffzN_AZrDw@mail.gmail.com>
On Thu, 17 Feb 2022 14:01:30 -0800
Andrii Nakryiko <andrii.nakryiko@gmail.com> wrote:
> > > Is there any chance to support this fast multi-attach for uprobe? If
> > > yes, we might want to reuse the same link for both (so should we name
> > > it more generically?
> >
> > There is no interface to do that but also there is no limitation to
> > expand uprobes. For the kprobes, there are some limitations for the
> > function entry because it needs to share the space with ftrace. So
> > I introduced fprobe for easier to use.
> >
> > > on the other hand BPF program type for uprobe is
> > > BPF_PROG_TYPE_KPROBE anyway, so keeping it as "kprobe" also would be
> > > consistent with what we have today).
> >
> > Hmm, I'm not sure why BPF made such design choice... (Uprobe needs
> > the target program.)
> >
>
> We've been talking about sleepable uprobe programs, so we might need
> to add uprobe-specific program type, probably. But historically, from
> BPF point of view there was no difference between kprobe and uprobe
> programs (in terms of how they are run and what's available to them).
> From BPF point of view, it was just attaching BPF program to a
> perf_event.
Got it, so that will reuse the uprobe_events in ftrace. But I think
the uprobe requires a "path" to the attached binary, how is it
specified?
> > > But yeah, the main question is whether there is something preventing
> > > us from supporting multi-attach uprobe as well? It would be really
> > > great for USDT use case.
> >
> > Ah, for the USDT, it will be useful. But since now we will have "user-event"
> > which is faster than uprobes, we may be better to consider to use it.
>
> Any pointers? I'm not sure what "user-event" refers to.
Here is the user-events series, which allows user program to define
raw dynamic events and it can write raw event data directly from
user space.
https://lore.kernel.org/all/20220118204326.2169-1-beaub@linux.microsoft.com/
Thank you,
--
Masami Hiramatsu <mhiramat@kernel.org>
next prev parent reply other threads:[~2022-02-18 4:07 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-02 13:53 [PATCH 0/8] bpf: Add fprobe link Jiri Olsa
2022-02-02 13:53 ` [PATCH 1/8] bpf: Add support to attach kprobe program with fprobe Jiri Olsa
2022-02-07 18:59 ` Andrii Nakryiko
2022-02-08 8:56 ` Jiri Olsa
2022-02-02 13:53 ` [PATCH 2/8] bpf: Add bpf_get_func_ip kprobe helper for fprobe link Jiri Olsa
2022-02-07 18:59 ` Andrii Nakryiko
2022-02-07 21:01 ` Alexei Starovoitov
2022-02-09 15:01 ` Jiri Olsa
2022-02-09 16:05 ` Andrii Nakryiko
2022-02-09 19:14 ` Jiri Olsa
2022-02-02 13:53 ` [PATCH 3/8] bpf: Add bpf_cookie support to fprobe Jiri Olsa
2022-02-07 18:59 ` Andrii Nakryiko
2022-02-08 9:07 ` Jiri Olsa
2022-02-08 23:35 ` Andrii Nakryiko
2022-02-08 23:46 ` Jiri Olsa
2022-02-08 23:53 ` Andrii Nakryiko
2022-02-02 13:53 ` [PATCH 4/8] libbpf: Add libbpf__kallsyms_parse function Jiri Olsa
2022-02-07 18:59 ` Andrii Nakryiko
2022-02-08 9:08 ` Jiri Olsa
2022-02-02 13:53 ` [PATCH 5/8] libbpf: Add bpf_link_create support for multi kprobes Jiri Olsa
2022-02-02 13:53 ` [PATCH 6/8] libbpf: Add bpf_program__attach_kprobe_opts " Jiri Olsa
2022-02-07 18:59 ` Andrii Nakryiko
2022-02-08 9:12 ` Jiri Olsa
2022-02-02 13:53 ` [PATCH 7/8] selftest/bpf: Add fprobe attach test Jiri Olsa
2022-02-02 13:53 ` [PATCH 8/8] selftest/bpf: Add fprobe test for bpf_cookie values Jiri Olsa
2022-02-07 18:59 ` Andrii Nakryiko
2022-02-08 9:15 ` Jiri Olsa
2022-02-08 23:24 ` Andrii Nakryiko
2022-02-02 17:09 ` [PATCH 0/8] bpf: Add fprobe link Alexei Starovoitov
2022-02-02 17:24 ` Jiri Olsa
2022-02-02 17:30 ` Alexei Starovoitov
2022-02-03 15:06 ` Jiri Olsa
2022-02-04 0:46 ` Masami Hiramatsu
2022-02-04 1:34 ` Alexei Starovoitov
2022-02-04 2:07 ` Masami Hiramatsu
2022-02-04 2:12 ` Alexei Starovoitov
2022-02-04 2:19 ` Steven Rostedt
2022-02-04 2:42 ` Alexei Starovoitov
2022-02-04 3:17 ` Masami Hiramatsu
2022-02-04 3:59 ` Masami Hiramatsu
2022-02-15 13:21 ` Jiri Olsa
2022-02-16 18:27 ` Andrii Nakryiko
2022-02-17 14:03 ` Masami Hiramatsu
2022-02-17 22:01 ` Andrii Nakryiko
2022-02-18 4:07 ` Masami Hiramatsu [this message]
2022-02-18 19:46 ` Andrii Nakryiko
2022-02-19 2:10 ` Alexei Starovoitov
2022-02-21 7:18 ` Masami Hiramatsu
2022-02-22 12:42 ` Jiri Olsa
2022-02-04 3:14 ` Masami Hiramatsu
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=20220218130727.51db96861c3e1c79b45daafb@kernel.org \
--to=mhiramat@kernel.org \
--cc=alexei.starovoitov@gmail.com \
--cc=andrii.nakryiko@gmail.com \
--cc=andrii@kernel.org \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=john.fastabend@gmail.com \
--cc=jolsa@redhat.com \
--cc=kafai@fb.com \
--cc=kpsingh@chromium.org \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=oleg@redhat.com \
--cc=olsajiri@gmail.com \
--cc=rostedt@goodmis.org \
--cc=songliubraving@fb.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;
as well as URLs for NNTP newsgroup(s).