From: Jiri Olsa <olsajiri@gmail.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>,
Jiri Olsa <olsajiri@gmail.com>,
Alexei Starovoitov <alexei.starovoitov@gmail.com>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Ingo Molnar <mingo@redhat.com>, bpf <bpf@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>,
Stanislav Fomichev <sdf@google.com>, Hao Luo <haoluo@google.com>,
LKML <linux-kernel@vger.kernel.org>,
Josh Poimboeuf <jpoimboe@redhat.com>
Subject: Re: [RFC] ftrace: Add support to keep some functions out of ftrace
Date: Mon, 15 Aug 2022 11:44:32 +0200 [thread overview]
Message-ID: <YvoVgMzMuQbAEayk@krava> (raw)
In-Reply-To: <Yvn9xR7qhXW7FnFL@worktop.programming.kicks-ass.net>
On Mon, Aug 15, 2022 at 10:03:17AM +0200, Peter Zijlstra wrote:
> On Sat, Aug 13, 2022 at 03:02:52PM -0400, Steven Rostedt wrote:
> > On Fri, 12 Aug 2022 23:18:15 +0200
> > Jiri Olsa <olsajiri@gmail.com> wrote:
> >
> > > the patch below moves the bpf function into sepatate object and switches
> > > off the -mrecord-mcount for it.. so the function gets profile call
> > > generated but it's not visible to ftrace
>
> Why ?!?
there's bpf dispatcher code that updates bpf_dispatcher_xdp_func
function with bpf_arch_text_poke and that can race with ftrace update
if the function is traced
the idea to solve it is to 'mark' the function independent of ftrace,
and add a way to make the function invissible to ftrace but with the
profile code fentry call generated
jirka
next prev parent reply other threads:[~2022-08-15 9:44 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20220722110811.124515-1-jolsa@kernel.org>
[not found] ` <20220722072608.17ef543f@rorschach.local.home>
[not found] ` <CAADnVQ+hLnyztCi9aqpptjQk-P+ByAkyj2pjbdD45dsXwpZ0bw@mail.gmail.com>
[not found] ` <20220722120854.3cc6ec4b@gandalf.local.home>
[not found] ` <20220722122548.2db543ca@gandalf.local.home>
[not found] ` <YtsRD1Po3qJy3w3t@krava>
[not found] ` <20220722174120.688768a3@gandalf.local.home>
[not found] ` <YtxqjxJVbw3RD4jt@krava>
[not found] ` <YvbDlwJCTDWQ9uJj@krava>
2022-08-13 19:02 ` [RFC] ftrace: Add support to keep some functions out of ftrace Steven Rostedt
2022-08-14 11:32 ` Steven Rostedt
2022-08-14 15:22 ` Jiri Olsa
2022-08-15 2:07 ` Chen Zhongjin
2022-08-15 8:04 ` Jiri Olsa
2022-08-15 11:01 ` Björn Töpel
2022-08-15 11:29 ` Jiri Olsa
2022-08-15 12:19 ` Björn Töpel
2022-08-15 12:30 ` Björn Töpel
2022-08-15 8:03 ` Peter Zijlstra
2022-08-15 9:44 ` Jiri Olsa [this message]
2022-08-15 12:37 ` Peter Zijlstra
2022-08-15 14:25 ` Alexei Starovoitov
2022-08-15 14:33 ` Peter Zijlstra
2022-08-15 14:45 ` Alexei Starovoitov
2022-08-15 15:02 ` Peter Zijlstra
2022-08-15 15:17 ` Alexei Starovoitov
2022-08-15 15:28 ` Peter Zijlstra
2022-08-15 15:35 ` Alexei Starovoitov
2022-08-15 15:44 ` Steven Rostedt
2022-08-15 15:53 ` Alexei Starovoitov
2022-08-15 16:13 ` Steven Rostedt
2022-08-15 15:48 ` Peter Zijlstra
2022-08-16 6:56 ` Jiri Olsa
2022-08-17 9:29 ` Jiri Olsa
2022-08-17 16:57 ` Alexei Starovoitov
2022-08-17 19:39 ` Jiri Olsa
2022-08-15 15:41 ` Peter Zijlstra
2022-08-15 15:49 ` Alexei Starovoitov
2022-08-15 16:08 ` Steven Rostedt
2022-08-18 20:27 ` Jiri Olsa
2022-08-18 20:50 ` Steven Rostedt
2022-08-18 21:00 ` Alexei Starovoitov
2022-08-18 21:05 ` Steven Rostedt
2022-08-18 21:32 ` Jiri Olsa
2022-08-19 11:45 ` Jiri Olsa
2022-08-23 17:23 ` Alexei Starovoitov
2022-08-26 8:00 ` Jiri Olsa
2022-08-18 21:14 ` Jiri Olsa
2022-08-15 15:32 ` Steven Rostedt
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