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Fri, 04 Sep 2026 09:16:29 -0700 (PDT) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Fri, 04 Sep 2026 09:16:28 -0700 Message-Id: Cc: "Gabriele Monaco" , "Nam Cao" , "LKML" , "linux-trace-kernel" , "bpf" , "Wen Yang" , "Tobias Schaffner" , "Viktor Malik" , "Linus Torvalds" Subject: Re: [RFC PATCH 00/20] rv: Add support for BPF monitors From: "Alexei Starovoitov" To: "Steven Rostedt" X-Mailer: aerc References: <20260831090524.106845-1-gmonaco@redhat.com> <87se3sakgi.fsf@yellow.woof> <20260903090211.50d15220@gandalf.local.home> <20260904074317.01b2c0e1@robin> In-Reply-To: <20260904074317.01b2c0e1@robin> On Fri Sep 4, 2026 at 4:43 AM PDT, Steven Rostedt wrote: > On Thu, 3 Sep 2026 20:30:19 -0700 > Alexei Starovoitov wrote: > >> > > On Wed, 2026-09-02 at 18:57 -0700, Alexei Starovoitov wrote: =20 >> > > > I don't think bpf fits here. I haven't seen active use of RV and e= ven less >> > > > so of any request from people who want this kind of programmabilit= y. >> > > > >> > > > So Nack for now. Sorry. =20 >> > > > >>=20 >> Ok. >> Please add >> Nacked-by: Alexei Starovoitov >>=20 >> when you submit it to Linus. >> Let him decide whether bpf maintainers have an authority >> to say where bpf is used in the kernel. > > When this is ready, I'll be happy to inform Linus on the pull request > that you NACKed it, if you are still against it by then. He's Cc'd on > this conversation now. But you left out any technical reason for the > NACK. You basically just said "I don't see how this is useful to me". > That's not a valid reason for a NACK. You added a whole bunch of hardcoded "monitors". None of them were necessary. The whole RV is imo a waste of kernel code. All of that could have been done via existing bpf tracing functionality. One can delete kernel/trace/rv and do the same thing with bpf. So I'm strongly against bolting bpf to RV as yet another "monitor". It's a wrong design. Keep adding hard coded monitors and don't mess with bpf. > Gabriele will be presenting this work at Linux Plumbers[1]. This will I didn't vote for it. Other bpf maintainers did. Hence it's in schedule. But my stance is still a nack.