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McKenney" , "Liam R. Howlett" , Gary Guo , Miguel Ojeda , =?iso-8859-1?Q?Bj=F6rn?= Roy Baron , Benno Lossin , Andreas Hindborg , Trevor Gross , Danilo Krummrich , Frederic Weisbecker , Neeraj Upadhyay , Joel Fernandes , Josh Triplett , Uladzislau Rezki , Steven Rostedt , Mathieu Desnoyers , Lai Jiangshan , Zqiang , Andrew Ballance , linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org, rcu@vger.kernel.org, maple-tree@lists.infradead.org, linux-mm@kvack.org Subject: Re: [PATCH RFC 0/2] rcu box container for Rust + maple tree load_rcu Message-ID: References: <20260116-rcu-box-v1-0-38ebfbcd53f0@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Stat-Signature: ynkoa3rsjj1uwm3qqcxbjfs8im1z98fw X-Rspamd-Queue-Id: 8E8BF40015 X-Rspam-User: X-Rspamd-Server: rspam02 X-HE-Tag: 1768658723-971076 X-HE-Meta: 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 Q5gY3YnG 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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 Sat, Jan 17, 2026 at 01:29:25PM +0000, Alice Ryhl wrote: > On Sat, Jan 17, 2026 at 09:11:49PM +0800, Boqun Feng wrote: > > In Rcu + RcuOld design, RcuBox is just a Box > > because these two pointer types handle reclaim + accesses. > > How would that work? Dropping my RcuBox<_> must use kfree_rcu() or > synchronize_rcu() or it is unsound. So it can't just be a Box. > RcuOld will call synchronize_rcu() before dropping `P`. And I think we can have an asynchronous drop pointer type like `RcuOld` that requires `P` is a type like `Box`, and the drop of `RcuOld, Async>` would be `call_rcu()` or `kfree_rcu()`. Regards, Boqun > Alice