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b=kW9YbLhrr+3qw/niJQupZPlXdIbDjOQ+zg42uQ/qSVCuE5BBw8o68+t4AYVjo0MMU 4HdNLuNuHPxg98rjv5h+Rkzelkj7XGGas5FtTYS4Mf75HIboXJOoOs/7JgFRj0O/CL QCBsyuYoNRyAGNSsj/6W1a2Fy8YEdCa1T23w73DVN2IBUSMSVb2lVLr72QdkT06DX5 osBB13IJSUKI/kecG4aMG0gNW8fb55KQJ3kpXNLDUHZ68q6junN1CDcxZg4f8LtYVf +oYz4K/X8Gtn3oTOmRzdU4qbjKswNSsMNnJzK84ynxT42vrU5YjQxvS/8iR/zg5Lb8 cUkwPcqYI/WNQ== Date: Wed, 12 Nov 2025 22:39:00 +0200 From: Mike Rapoport To: Pasha Tatashin Cc: pratyush@kernel.org, jasonmiu@google.com, graf@amazon.com, 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, ptyadav@amazon.de, lennart@poettering.net, brauner@kernel.org, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, saeedm@nvidia.com, ajayachandra@nvidia.com, jgg@nvidia.com, parav@nvidia.com, leonro@nvidia.com, witu@nvidia.com, hughd@google.com, skhawaja@google.com, chrisl@kernel.org Subject: Re: [PATCH v5 06/22] liveupdate: luo_session: add sessions support Message-ID: References: <20251107210526.257742-1-pasha.tatashin@soleen.com> <20251107210526.257742-7-pasha.tatashin@soleen.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251107210526.257742-7-pasha.tatashin@soleen.com> X-Stat-Signature: i884fbez6qsa1qpd6ccf134kj1monnds X-Rspam-User: X-Rspamd-Queue-Id: 589DE2000C X-Rspamd-Server: rspam01 X-HE-Tag: 1762979966-419251 X-HE-Meta: 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 F6NzGa3a FhggOJnv1e4kcz3DfAqivGTMXiOX6drSzbLO5wmX0D5mGPb+VCfMoAHwRQTLucDfigagfu1mjYR3RH5D4QaSxs4u3Ezt3K8cp1EY5xWKgpGyMDhEauTF5HVL+d+lu9RYbLFovM4I7n8ndu0l/CmhHpZCqhwIOzuFrbqdrpwBn5TKTu/PzZlejwsCoukheUGFkyccxanut3js3PMffHLbL3iVUZ6LdfO+ovWo9d7kQMtTduWi4LsGFWoIoNVBtY83fFmRdqGluzyeYPP8Y5W9k14T+TsJ/il+j+3xOaqILJfw2fEcfFRTCFVgF89bDXmzautsZcnzegxQg9rSc2O65g8fKK56xgiQE/Q/LBDBcwbcG0BvtBWH5IJ8kNcy6yMOClR0JJxTXV7qWycs= 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 Fri, Nov 07, 2025 at 04:03:04PM -0500, Pasha Tatashin wrote: > Introduce concept of "Live Update Sessions" within the LUO framework. > LUO sessions provide a mechanism to group and manage `struct file *` > instances (representing file descriptors) that need to be preserved > across a kexec-based live update. > > Each session is identified by a unique name and acts as a container > for file objects whose state is critical to a userspace workload, such > as a virtual machine or a high-performance database, aiming to maintain > their functionality across a kernel transition. > > This groundwork establishes the framework for preserving file-backed > state across kernel updates, with the actual file data preservation > mechanisms to be implemented in subsequent patches. > > Signed-off-by: Pasha Tatashin > --- > include/linux/liveupdate/abi/luo.h | 81 ++++++ > include/uapi/linux/liveupdate.h | 3 + > kernel/liveupdate/Makefile | 3 +- > kernel/liveupdate/luo_core.c | 9 + > kernel/liveupdate/luo_internal.h | 39 +++ > kernel/liveupdate/luo_session.c | 405 +++++++++++++++++++++++++++++ > 6 files changed, 539 insertions(+), 1 deletion(-) > create mode 100644 kernel/liveupdate/luo_session.c > > diff --git a/include/linux/liveupdate/abi/luo.h b/include/linux/liveupdate/abi/luo.h > index 9483a294287f..37b9fecef3f7 100644 > --- a/include/linux/liveupdate/abi/luo.h > +++ b/include/linux/liveupdate/abi/luo.h > @@ -28,6 +28,11 @@ > * / { > * compatible = "luo-v1"; > * liveupdate-number = <...>; > + * > + * luo-session { > + * compatible = "luo-session-v1"; > + * luo-session-head = ; 'head' reads to me as list head rather than a header. I'd use 'hdr' for the latter. -- Sincerely yours, Mike.