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AJvYcCXYhX4wx1KnqVic6H/4HE70qnvd5Sz8lW2AhpliQNx7XiCLkhcbjHeAVbIX9upoXbyZVDmV3qI4lg==@kvack.org X-Gm-Message-State: AOJu0YyFn6duX6kRFQPqhVWoQlGGY50JILQnVEGw+XH3CnHxnkN10Usx H9IG8iBJMAllNNvxrvfz4J0+lc3yF26pMPlgrMzUeb3b0a9vSLGI3xuH2Q+C5lx66/iuuuiDyW+ nccxq4kVeSSEHOZceRoSAWhiR2740RPGxoEJKmTQnHg== X-Gm-Gg: ASbGncvpGSssONXSS0MXs14siYQqDRtr0l8toj7Wsb3RfHB2QcK3QxxbdHFyJ7C6TZy iyNIkbVwAcLDx5NPmlMR8Rs24Wul/RI8MB2jdIGSHOEUGz+gfI6G+i3NgAdTB+gAQ0X7RjK8se5 yTdFtOP29AczYmm7WPGFTkwGYHsQiJrJ1B5qWInlUJUO9hC+k2iQmfYA91YO/i2qx9uoamrIB4f 4yu+OI6+zqX+BMfUtft/OZdnjf1EWh1MOou8wc= X-Google-Smtp-Source: AGHT+IFwm4V/zCKBkbgm7pfKIp77PJD1NOmB2z+7xVCEcG6LKB3NFoKIKgya5mufGjYCV3AhGt61yn25CRIzX8BM9QU= X-Received: by 2002:ac8:5fc5:0:b0:4b7:a7b6:eafc with SMTP id d75a77b69052e-4e576a5c404mr198174771cf.13.1759767511840; Mon, 06 Oct 2025 09:18:31 -0700 (PDT) MIME-Version: 1.0 References: <20250929010321.3462457-1-pasha.tatashin@soleen.com> <20250929010321.3462457-4-pasha.tatashin@soleen.com> In-Reply-To: From: Pasha Tatashin Date: Mon, 6 Oct 2025 12:17:53 -0400 X-Gm-Features: AS18NWC8dVdnh9WrIeR8a0qx05q3jEVozl0VBzvOu40iLLzMHk8IAd4vKASusLs Message-ID: Subject: Re: [PATCH v4 03/30] kho: drop notifiers 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, 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, steven.sistare@oracle.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: DA2B7120002 X-Rspamd-Server: rspam11 X-Rspam-User: X-Stat-Signature: c7zwrjj6dbxo9zjhzigwasthg3rfajx6 X-HE-Tag: 1759767514-728758 X-HE-Meta: U2FsdGVkX195UugZ8Svo8ROzmr76AV1DD2m2Q+a1kiKOZRL5ZLTcwZbT6PmCgc0It4EmMilbPvZLoNP80cNBPApY80tRLPEB6T3I+jQttyQHYhBNAP2wvK3MhX5XgfYj9OaYp8yWIDyZcodv1cYuWadxcy5xfy9PxfNIwThGecZfb59XZWCjsJaOajk31Qr8gxUj7nPlsy9uLFJM6Y3UFX1B2G3Arm9Ad/c6Hs7+XlrakdjW3GlxaaCd+jHL6X3/RQu9B90SQq7bz3vwxxinmbkCPrp2HWFA0H5B05E5ypFYzf4hHzmNkfYoRUnO5mhalonCZ4utDETU6Isj8xWFP+hlu7PAeyEOCSltcRFY0C5dwuEI8If9MSWghpke64yxzYwUd+pekGqvOobAISGT+8CwEv8XckHYG7yIQj432BqJHUwRIgokkKgXi6mPpfifRFpRloxVIifRRI0BrSTgvwWo1ygQRwBmUL/8YFnxNDUeDRXY3++9WLb70TysU0tmH5CrevFRkkPoUNDjIV+gAj7yc66PYPGrvDPKGD20QnwEYlbZpX6iQ2rDAm6deWf9cKHV9f+9kZ2E8zLZWyoX3pEoQtLI3MklVVXR/VEZiZk6YaFXL5c8WdIUoXnMZHlJABdaiFP5DYRDNpJiBTsWj2A75JT1ciOZAMEyd09mhScFzIePzMmNUSts9PcFTw7ETZ+XsEopXObBMizP3acd+RT2Xv/ETvAw2NTp3MpOFkIo1lCS9BZcF/DbFnXsN8JrkHDXoEvM3cdMrhbyHNlJkvzoFduh36DFe74ZeWupzehJFYN256RjO+RmOG6jsdTxUBj57utR7F32vly/eEvAxIKwyTVajGluZxCYazLRNhJzdTU7Cxx8I+Z8M7zVcIcsIBIPIOGHP2WqnPrKNRWFdiMDkp6Ubehu+cin3b3ER5Rn5TTM2uCcrjn04e0Kt3bbSU+CJa5D6yBN71c4mCM V6FPGalJ OEnfu 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 Mon, Oct 6, 2025 at 10:30=E2=80=AFAM Pratyush Yadav wrote: > > Hi Pasha, > > On Mon, Sep 29 2025, Pasha Tatashin wrote: > > > From: "Mike Rapoport (Microsoft)" > > > > The KHO framework uses a notifier chain as the mechanism for clients to > > participate in the finalization process. While this works for a single, > > central state machine, it is too restrictive for kernel-internal > > components like pstore/reserve_mem or IMA. These components need a > > simpler, direct way to register their state for preservation (e.g., > > during their initcall) without being part of a complex, > > shutdown-time notifier sequence. The notifier model forces all > > participants into a single finalization flow and makes direct > > preservation from an arbitrary context difficult. > > This patch refactors the client participation model by removing the > > notifier chain and introducing a direct API for managing FDT subtrees. > > > > The core kho_finalize() and kho_abort() state machine remains, but > > clients now register their data with KHO beforehand. > > > > Signed-off-by: Mike Rapoport (Microsoft) > > Signed-off-by: Pasha Tatashin > > This patch breaks build of test_kho.c (under CONFIG_TEST_KEXEC_HANDOVER): > > lib/test_kho.c:49:14: error: =E2=80=98KEXEC_KHO_ABORT=E2=80=99 un= declared (first use in this function) > 49 | case KEXEC_KHO_ABORT: > | ^~~~~~~~~~~~~~~ > [...] > lib/test_kho.c:51:14: error: =E2=80=98KEXEC_KHO_FINALIZE=E2=80=99= undeclared (first use in this function) > 51 | case KEXEC_KHO_FINALIZE: > | ^~~~~~~~~~~~~~~~~~ > [...] > > I think you need to update it as well to drop notifier usage. Yes, thank you Pratyush. I missed this change in my patch. Pasha