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From:   Song Liu <songliubraving@fb.com>
To:     Alexei Starovoitov <alexei.starovoitov@gmail.com>
CC:     "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "ast@kernel.org" <ast@kernel.org>,
        "daniel@iogearbox.net" <daniel@iogearbox.net>,
        "acme@kernel.org" <acme@kernel.org>,
        "peterz@infradead.org" <peterz@infradead.org>,
        Kernel Team <Kernel-team@fb.com>
Subject: Re: [PATCH perf,bpf 5/5] perf util: generate bpf_prog_info_event for
 short living bpf programs
Thread-Topic: [PATCH perf,bpf 5/5] perf util: generate bpf_prog_info_event for
 short living bpf programs
Thread-Index: AQHUgdQ+kfQLaz1BnkqiHcRIr5oTIaVayrqAgAAGpQA=
Date:   Wed, 21 Nov 2018 22:35:35 +0000
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 <20181121195502.3259930-6-songliubraving@fb.com>
 <20181121221145.2cxph7zv27x7lbg6@ast-mbp>
In-Reply-To: <20181121221145.2cxph7zv27x7lbg6@ast-mbp>
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> On Nov 21, 2018, at 2:11 PM, Alexei Starovoitov <alexei.starovoitov@gmail=
.com> wrote:
>=20
> On Wed, Nov 21, 2018 at 11:55:02AM -0800, Song Liu wrote:
>> This patch enables perf-record to listen to bpf_event and generate
>> bpf_prog_info_event for bpf programs loaded and unloaded during
>> perf-record run.
>>=20
>> To minimize latency between bpf_event and following bpf calls, separate
>> mmap with watermark of 1 is created to process these vip events. Then
>> a separate dummy event is attached to the special mmap. A separate threa=
d
>> is used to only poll bpf events.
>>=20
>> By default, perf-record will listen to bpf_event. Option no-bpf-event is
>> added in case the user would opt out.
>=20
> I think only default perf-record for sampling should include it.
> perf record -e for tracepoints, kprobes and anything else should imply no=
-bpf-event.
>=20

Maybe something like
 =20
   if (software_event && ! -g)
        no_bpf_event =3D true;

?

This will allow attaching kprobe on bpf helper and see which bpf program
calls it.=20

Thanks,
Song=