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[103.168.172.201]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-4ab82242a82sm19477561cf.35.2025.07.16.08.35.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 16 Jul 2025 08:35:28 -0700 (PDT) Received: from phl-compute-05.internal (phl-compute-05.phl.internal [10.202.2.45]) by mailfauth.phl.internal (Postfix) with ESMTP id 731E1F40067; Wed, 16 Jul 2025 11:35:27 -0400 (EDT) Received: from phl-mailfrontend-02 ([10.202.2.163]) by phl-compute-05.internal (MEProxy); Wed, 16 Jul 2025 11:35:27 -0400 X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeeffedrtdefgdehkedtlecutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpuffrtefokffrpgfnqfghnecuuegr ihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjug hrpeffhffvvefukfhfgggtuggjsehttdertddttddvnecuhfhrohhmpeeuohhquhhnucfh vghnghcuoegsohhquhhnrdhfvghnghesghhmrghilhdrtghomheqnecuggftrfgrthhtvg hrnhephedugfduffffteeutddvheeuveelvdfhleelieevtdeguefhgeeuveeiudffiedv necuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomhepsghoqh hunhdomhgvshhmthhprghuthhhphgvrhhsohhnrghlihhthidqieelvdeghedtieegqddu jeejkeehheehvddqsghoqhhunhdrfhgvnhhgpeepghhmrghilhdrtghomhesfhhigihmvg drnhgrmhgvpdhnsggprhgtphhtthhopedukedpmhhouggvpehsmhhtphhouhhtpdhrtghp thhtoheplhhoshhsihhnsehkvghrnhgvlhdrohhrghdprhgtphhtthhopehlvghvhihmih httghhvghllhdtsehgmhgrihhlrdgtohhmpdhrtghpthhtohepohhjvggurgeskhgvrhhn vghlrdhorhhgpdhrtghpthhtoheprghlvgigrdhgrgihnhhorhesghhmrghilhdrtghomh dprhgtphhtthhopehgrghrhiesghgrrhihghhuohdrnhgvthdprhgtphhtthhopegsjhho rhhnfegpghhhsehprhhothhonhhmrghilhdrtghomhdprhgtphhtthhopegrrdhhihhnug gsohhrgheskhgvrhhnvghlrdhorhhgpdhrtghpthhtoheprghlihgtvghrhihhlhesghho ohhglhgvrdgtohhmpdhrtghpthhtohepthhmghhrohhsshesuhhmihgthhdrvgguuh X-ME-Proxy: Feedback-ID: iad51458e:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Wed, 16 Jul 2025 11:35:26 -0400 (EDT) Date: Wed, 16 Jul 2025 08:35:26 -0700 From: Boqun Feng To: Benno Lossin Cc: Mitchell Levy , Miguel Ojeda , Alex Gaynor , Gary Guo , =?iso-8859-1?Q?Bj=F6rn?= Roy Baron , Andreas Hindborg , Alice Ryhl , Trevor Gross , Andrew Morton , Dennis Zhou , Tejun Heo , Christoph Lameter , Danilo Krummrich , linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH v2 3/5] rust: percpu: add a rust per-CPU variable test Message-ID: References: <20250712-rust-percpu-v2-0-826f2567521b@gmail.com> <20250712-rust-percpu-v2-3-826f2567521b@gmail.com> <68762e19.170a0220.33e203.a0b7@mx.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Stat-Signature: ya7i3rrkd759afoubk4c3q6t5tmtfu9k X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: DDBE7140002 X-Rspam-User: X-HE-Tag: 1752680129-299947 X-HE-Meta: U2FsdGVkX1+rBeM/h/HEaFhfijHxYmHxludfdqrYlHVMUWCPdUQfkD+vBL+0FWNVIpHdMRFeYnare2YLIkmpm5GLX12I1gIMwxf6dFGk3bKRfrp82DwbZsI9/3eJq3xSgLnMoGOCQ3Q/M4FwN6dZ8dtsprU7eCnsAOlihWvK0QhTAdpL21l+VK5R7WJh/6x0Nz7waXU3+c/+OGbtQtw0LZPRsibpkrw1nAfuQvLjk2/vt/CWck4WXspOC42VX2R9roOFCTsEFVkDiQNKES+8Y6JiFGEMUfFyEyUVnPjMWzsvJ6lzCHawpqLWYRRLQsOtVujmzRYnKoyJrHjyWTU7MCDaxXlnPvCSX6aienRXsDaoCoeHnxXYNeRWwuyZgiwrrBrxu9PXpEp9pNGj/1GiL6LvQSOJwm8omQcwmLOntbkzIf+WTIpTLtFc/36R2GTivZU1s9ITz5TCdBbMVf0gfhMsRSLxyK5fkqmZEnIKjWwgEnyGnOohOrE4/8i8jAOOWds4ozUGb0jZvTaJs0mkEOYzeuLifGTEIDgezjrdvNhNkVJhwmdEsjEHKgJ+msD57sIzgztT7Jl9SWa2P8fyLRxd6FoTedor2+wzp1L9z+ICukVNeyIeJBmZr0iKYOiyD1vry1KqEPxyTWJfz4qcgepQImPijoOwvgY1sVl6DereqPIlFjhT8xkuuHrpnbqcUAMz8fkL+kWUs85tGXIMyy7Ya862maqeIk3OG74w1QSQM98OjdXB5Fta0n4OLLdM20qZl7wIb5t8IvwRFGmhau3lSEmIrVM7Yn/9mrg/RKwu9PR4o4WzKdyQj6zkKczT2kEyyGroE/jxB8MNgG6awE5q5VEdOPgL+M3gQYz9pyl2JyZCEKjSI6Yn/tCJoS/hqUwtXxR2WfCdxh9t8EZ9udJNDRUm1vcVGqSENOw2JDtGYGX9TAQd0zDOKJhMVz8H30mn9QV+X9ek/L+0EVq N8ezBOpJ 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 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 Tue, Jul 15, 2025 at 07:44:01PM +0200, Benno Lossin wrote: [...] > >> > >> Sure we can do some experimentation, but I don't think we should put > >> unsafe abstractions upstream that we intend to replace with a safe > >> abstraction later. Otherwise people are going to depend on it and it's > > > > I doubt we can replace the unsafe abstraction with a safe one, if users > > really care the performance then they would really need to use some > > unsafe API to build their safe abstraction. > > That sounds pretty pessimistic, why do you think that? > I could ask you the similar, you barely know the implementation and usage the percpu, why do you think it's possible? ;-) Regards, Boqun