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AJvYcCUR/IhIvCIPys4LAnGXDSYEelahQFqI4TXmpJy4VYZPwAfxt3QXn3Qtl8nvXSSAF0tNda/mkH2lng==@kvack.org X-Gm-Message-State: AOJu0YyiUaiDqTStY/OnTupPzmywe/BdxYQiPsTLu1dL9Hwww63SuOIh BUl2cy8qFx+k2f6yS+4VnhKbxpk8db9vfLEi+BJZR3XjV7X/th/2zwLUsQ84Ie0dWNyVjaldxYg 4L6mINhJItXG80hAirWkTMS6JZFl5cdj8qRoTzT06nQ== X-Gm-Gg: ASbGncvYN0CAOH38kaAkseDgZjiPPWyITWujK2cKRk62YLEu+tXcirRvZAiVkfsR4PS I84im/SzYiTfGlmItYdC/pNoU1EbssGdjj6+gzVzs0DPVdxucME0jaUTnAyQGvei3wHh9JwFo4H XpKrC3G9WvOiaL5Bw9q/u3eybF+Q0XQA== X-Google-Smtp-Source: AGHT+IG7TGR/SrekoDc0+onJRf0onfQpl+KhRAPN38op7Z3+HE8nHerXh4JUuGRqCdAEroRR8Wt0dCQLMoLZ0skTHL0= X-Received: by 2002:a05:622a:2606:b0:476:8fcb:9aa3 with SMTP id d75a77b69052e-4a5b9a2891dmr242085871cf.13.1749400641136; Sun, 08 Jun 2025 09:37:21 -0700 (PDT) MIME-Version: 1.0 References: <20250515182322.117840-1-pasha.tatashin@soleen.com> <20250515182322.117840-12-pasha.tatashin@soleen.com> In-Reply-To: From: Pasha Tatashin Date: Sun, 8 Jun 2025 12:36:44 -0400 X-Gm-Features: AX0GCFuZQeD3HS-9cAYV1p6O4Tqr1uPw5wV4go1oCDGi974z2b27RRui1WzOPv8 Message-ID: Subject: Re: [RFC v2 11/16] luo: luo_sysfs: add sysfs state monitoring To: Pratyush Yadav Cc: jasonmiu@google.com, graf@amazon.com, changyuanl@google.com, rppt@kernel.org, dmatlack@google.com, rientjes@google.com, corbet@lwn.net, rdunlap@infradead.org, ilpo.jarvinen@linux.intel.com, kanie@linux.alibaba.com, ojeda@kernel.org, aliceryhl@google.com, masahiroy@kernel.org, akpm@linux-foundation.org, tj@kernel.org, yoann.congal@smile.fr, mmaurer@google.com, roman.gushchin@linux.dev, chenridong@huawei.com, axboe@kernel.dk, mark.rutland@arm.com, jannh@google.com, vincent.guittot@linaro.org, hannes@cmpxchg.org, dan.j.williams@intel.com, david@redhat.com, joel.granados@kernel.org, rostedt@goodmis.org, anna.schumaker@oracle.com, song@kernel.org, zhangguopeng@kylinos.cn, linux@weissschuh.net, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, gregkh@linuxfoundation.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, rafael@kernel.org, dakr@kernel.org, bartosz.golaszewski@linaro.org, cw00.choi@samsung.com, myungjoo.ham@samsung.com, yesanishhere@gmail.com, Jonathan.Cameron@huawei.com, quic_zijuhu@quicinc.com, aleksander.lobakin@intel.com, ira.weiny@intel.com, andriy.shevchenko@linux.intel.com, leon@kernel.org, lukas@wunner.de, bhelgaas@google.com, wagi@kernel.org, djeffery@redhat.com, stuart.w.hayes@gmail.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspam-User: X-Stat-Signature: n4nen6jo9pckt7obid1erzumbz36cosb X-Rspamd-Queue-Id: F326B1C0005 X-Rspamd-Server: rspam11 X-HE-Tag: 1749400641-944435 X-HE-Meta: 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 ty47IYD7 qPhjLm0IzAvd69q7O/Ua+Vfsp+scbNV33JiFwfRg0w0rh2m/MqdVpxCd9Ewr9IpaSakOct7GrYitWR4nt0GqzMDnQwqTcpRnZTufIg/UMETv+DZ84R2N86RYTw0JdDYVi35HD1AcI5DVI5vCawTPM2y1tekb1natWY9rfQc2HYhvChBiBMxVY7rpgnNXT87EoQAv3lICxNkz7kTMj96G4TTRj+UNtryhmVmMDB7i02sD4GIxjJ2ydeOdLoIpkoRBo0lbLv+IfMrEpMa3hreHXrEfQxYJtpGkF65ZIDrs7gDix/dY+f+Gax0EwmhDuebPIP2UmMG0ZIr9s5on5leVMtlVE3Pcml5aDeFno7yW6YN4sHbpEHxI94+vZrDpf/eo6bf9EVTn+U2y6Zsn1CuuHWPCOOq7sZgrDxeS3lZOEwMoodW4Z93W9RigcZI6ELqsARj/4brQBrELHYx0= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, Jun 5, 2025 at 12:20=E2=80=AFPM Pratyush Yadav wrote: > > On Thu, May 15 2025, Pasha Tatashin wrote: > > > Introduce a sysfs interface for the Live Update Orchestrator > > under /sys/kernel/liveupdate/. This interface provides a way for > > userspace tools and scripts to monitor the current state of the LUO > > state machine. > > I am not sure if adding and maintaining a new UAPI that does the same > thing is worth it. Can't we just have commandline utilities that can do > the ioctls and fetch the LUO state, and those can be called from tools > and scripts? > This is based on discussion from SystemD people. It is much simpler for units to check the current 'state' via sysfs, and act accordingly. > > > > The main feature is a read-only file, state, which displays the > > current LUO state as a string ("normal", "prepared", "frozen", > > "updated"). The interface uses sysfs_notify to allow userspace > > listeners (e.g., via poll) to be efficiently notified of state changes. > > > > ABI documentation for this new sysfs interface is added in > > Documentation/ABI/testing/sysfs-kernel-liveupdate. > > > > This read-only sysfs interface complements the main ioctl interface > > provided by /dev/liveupdate, which handles LUO control operations and > > resource management. > > > > Signed-off-by: Pasha Tatashin > [...] > > -- > Regards, > Pratyush Yadav