Date:   Thu, 13 Jan 2022 22:18:45 +0900
From:   Masami Hiramatsu <mhiramat@kernel.org>
To:     Jiri Olsa <jolsa@redhat.com>
Cc:     Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>, netdev@vger.kernel.org,
        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>,
        Steven Rostedt <rostedt@goodmis.org>,
        "Naveen N . Rao" <naveen.n.rao@linux.ibm.com>,
        Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>,
        "David S . Miller" <davem@davemloft.net>
Subject: Re: [RFC PATCH v2 0/8] fprobe: Introduce fprobe function entry/exit
 probe
Message-Id: <20220113221845.1d4564212fe401ad3d624d0d@kernel.org>
In-Reply-To: <YeAatqQTKsrxmUkS@krava>
References: <164199616622.1247129.783024987490980883.stgit@devnote2>
        <Yd77SYWgtrkhFIYz@krava>
        <YeAatqQTKsrxmUkS@krava>
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Precedence: bulk

On Thu, 13 Jan 2022 13:27:34 +0100
Jiri Olsa <jolsa@redhat.com> wrote:

> On Wed, Jan 12, 2022 at 05:01:15PM +0100, Jiri Olsa wrote:
> > On Wed, Jan 12, 2022 at 11:02:46PM +0900, Masami Hiramatsu wrote:
> > > Hi Jiri and Alexei,
> > > 
> > > Here is the 2nd version of fprobe. This version uses the
> > > ftrace_set_filter_ips() for reducing the registering overhead.
> > > Note that this also drops per-probe point private data, which
> > > is not used anyway.
> > > 
> > > This introduces the fprobe, the function entry/exit probe with
> > > multiple probe point support. This also introduces the rethook
> > > for hooking function return as same as kretprobe does. This
> > 
> > nice, I was going through the multi-user-graph support 
> > and was wondering that this might be a better way
> > 
> > > abstraction will help us to generalize the fgraph tracer,
> > > because we can just switch it from rethook in fprobe, depending
> > > on the kernel configuration.
> > > 
> > > The patch [1/8] and [7/8] are from your series[1]. Other libbpf
> > > patches will not be affected by this change.
> > 
> > I'll try the bpf selftests on top of this
> 
> I'm getting crash and stall when running bpf selftests,
> the fprobe sample module works fine, I'll check on that

Hmm, would you mean tools/testing/selftests/bpf/prog_tests/ ?
Let me check it too.

Thank you,

-- 
Masami Hiramatsu <mhiramat@kernel.org>