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Tue, 09 Sep 2025 09:26:22 -0700 (PDT) MIME-Version: 1.0 References: <20250807014442.3829950-1-pasha.tatashin@soleen.com> <20250807014442.3829950-30-pasha.tatashin@soleen.com> <20250826162019.GD2130239@nvidia.com> <20250828124320.GB7333@nvidia.com> <20250902134846.GN186519@nvidia.com> <20250903150157.GH470103@nvidia.com> <20250904144240.GO470103@nvidia.com> In-Reply-To: From: Pasha Tatashin Date: Tue, 9 Sep 2025 12:25:44 -0400 X-Gm-Features: Ac12FXx6epo0S67QSojcQ_-q7eHBI3YWc1_bazn-CLdcZQ8RS6cUC5rSpC48xWE Message-ID: Subject: Re: [PATCH v3 29/30] luo: allow preserving memfd To: Pratyush Yadav Cc: Jason Gunthorpe , Pratyush Yadav , 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, parav@nvidia.com, leonro@nvidia.com, witu@nvidia.com Content-Type: text/plain; charset="UTF-8" X-Stat-Signature: qas9ikzry9bo1p1saj1o119zmm9a9nmx X-Rspam-User: X-Rspamd-Queue-Id: AFE37C000C X-Rspamd-Server: rspam04 X-HE-Tag: 1757435183-763199 X-HE-Meta: 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 fnHU163E MSDvLdQAkoVlrN+UaQFTuBxK+l7Bc65mF1JNxMgkzZP4rwtaUJ5McK/JkXW2+UzUXw9X+BSm/4ZlG/91O9TevLoDp5/lLO059niUbpk45yrG44U3EmTNudUvCSdexfxuznUZ2MSD2zDZ76mtKpe2bLZW/dbTdbl+WXTUKh8kuzL0+s5FZVigCT/MTKehBD6+GOad5Z8YyhHh5x+oQmddKqdaS959K4IU+4RDYqm6OwJ/m2efYdF9L11p824tLFYdotjcxfEMv1x3J9kR/Hd5cVXpRDB69ItHVfD67bAQ7H8ZU9Qc= 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: > I think it would help with making a wider range of roll back and forward > options available. For example, if your current kernel can speak version > A and B, and you are rolling back to a kernel that only speaks A, this > information can be used to choose the right serialization formats. At least for upstream, we discussed not to support rolling back (this can be revised in the future), but for now rollback is something that would need to be taken care of downstream. Pasha