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Peter Anvin" , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Jonathan Corbet , Shuah Khan , Shuah Khan , Vishal Annapurve , Andrew Morton , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Youngjun Park , Qi Zheng , Shakeel Butt , Kiryl Shutsemau , Baoquan He , Jason Gunthorpe , Vlastimil Babka , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, linux-coco@lists.linux.dev Content-Type: text/plain; charset="us-ascii" X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: CCFD2140009 X-Stat-Signature: ukerx6ztacn83z5in1mp6cykc9c19h36 X-HE-Tag: 1782500802-103116 X-HE-Meta: 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 OKl3fzuM OSK8/C37EpJIQC4b8jlkpg0NX4qkKFnJ4lps52c52rOK0TEj1KJRidbtHAxTtALpw2ptEJdAJzHrpVL40kzh1pxCMkErEu/63duWNpw5gjflCSdOL9941Dwr3lEJOnzbRzUXNx+IsDwKU74gnXCL8CSklqEZr/GDDTIZw8oakg8uxP+OlJahkleA44O8Q1wx+kgYPVI5nuri7QjK5u7Dg0VC3IuzD/ZIbWst2tTKAsEfi9c/fZXdIMfTPYWKVoMLU+AWHMNRv5Tfue6l2AefiM/unT+hYJzRztuzVEyBqSKXwymiFbpiQQet5uHHZSjlbsEDuMLNJFXydiyyHRZrUS61crXx4owN5E0+nZVh+SHlgtRpz4ysTnxT9/ebe4X2budG2OWzabeal8pGr9X3snt792lNtXHWThSY7inuj3fk4BuFFH4Gf451N3EQtv7tSbeiC4EaaQSxZ3CPoPGi04RtpWj6NpMK9ymEbDNMmZMMKw5FxM6whW9I5KyR4/RXojTp0UI5QRVwE/ppgJdTXknYQJbiutTBS9i1mSe0xoQDQsnkVANJUxpE81ro/BPZUmYUfx17rV5wgm2WjV6m9vnx2ByZm/dBRclNO5t+6pBggmYF+mF3N+Yub6amQZ3nTocJJHr4ClzAx1lI= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, Jun 26, 2026, Yan Zhao wrote: > On Thu, Jun 25, 2026 at 07:36:28AM -0700, Sean Christopherson wrote: > > On Thu, Jun 25, 2026, Yan Zhao wrote: > > And I'm not remotely convinced that prepending allow_ to the param will help > > end users diagnose "unexpected" memory consumption, in quotes because anyone that > > is deploying a stack that utilizes out-of-place conversion absolutely needs to > > understand and plan for the additional memory consumption. I.e. if the memory > > consumption is "unexpected" to the end user, they likely have far bigger problems. > My first impression of gmem_in_place_conversion=true was that it enforces gmem > in-place conversion. However, it actually only enforces per-gmem private/shared > attribute. > My worry was that people might think it's a kernel bug if userspace can still > have shared memory from other sources after they configured > gmem_in_place_conversion=true. Ah, I see where you're coming from. FWIW, truly enforcing in-place conversion is flat out impossible. E.g. userspace can simply replace the memslot, at which point the memory effectively reverts to shared. > However, I have no strong opinion if you think gmem_in_place_conversion is good, > and with the above documentation. :) Ya, I think this largely a documentation problem. I agree that a param name like gmem_private_memory_attributes would be more precise, but I think it'd be far less informative for the vast majority of users that only care whether or not KVM can do in-place conversion, and don't care about how that is done.