From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f74.google.com (mail-wm1-f74.google.com [209.85.128.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9F89D333720 for ; Sat, 17 Jan 2026 13:29:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768656572; cv=none; b=PXtIrsiDuth3Ugq+taip3A9OeHmyGaojEkPtu2TJfpeipex+lD8QOrFSxn+pkCRQSxrxgjR7AsK9gSs7j5rwUsxab66JkaBZWkIjCFKcIXKEX3X/6nXsWkEFHqxKMG06uO1YccSfFSM9ujJBqbQ0Ra/WM86q0e5G02cCkGYf93s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768656572; c=relaxed/simple; bh=yGX0/BmN4QSqMec6LsJaLEgukSwhg32D3RH18NXGaE8=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=YbKS36m5nYQfrpUrQWnab2XePKKlrc2ZQkZpmmf3aVNXhWo1YWorlAxcq+XCjEhH1WGly4Itmai7G8YDJDxG/dSxKt6iummQuYCAWKABl1LYYJF/mmbfcWWLUTpgcxlM2O4CEykYtsZ/7eEmNmwIVe3X/JwRXQfGajnL8VTr5B8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--aliceryhl.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=OMmoqa4z; arc=none smtp.client-ip=209.85.128.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--aliceryhl.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="OMmoqa4z" Received: by mail-wm1-f74.google.com with SMTP id 5b1f17b1804b1-47d3ba3a49cso31527485e9.2 for ; Sat, 17 Jan 2026 05:29:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1768656567; x=1769261367; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=yGX0/BmN4QSqMec6LsJaLEgukSwhg32D3RH18NXGaE8=; b=OMmoqa4zagEyy7TtwRhjLszgMA2QqyBdA0uSwG+DMytf4uLSA3VnypEjrM8fvx/dTf HtHD+cvLn49bOCxh/fMtupnz+Z4r18KevyNKGkZo3hT3l4iDdkyuTbuWVFjM3z6DSGkA ZmIi0WjkrvD1ghTXhnVZnlrr94B6ZhzEctkIEN48wISPtlGUOsljfHTvOFtCliyfBqb0 uljFDcyEqAX88ZPDQKqZ6CYSDar2SJ7KqHit1lFaZBfQgLXEAsKLU5NY1DoriZaw7/sl Bua8Hwk1jGkvsmEt7tnFBrvEW0caMtgGFcLLYtUtqw54lxZpF867PSit5C9aSwRtCSpP 3ZbQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1768656567; x=1769261367; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=yGX0/BmN4QSqMec6LsJaLEgukSwhg32D3RH18NXGaE8=; b=K2/EI/JQ9ohr9z1zIwYei6LRbhI5UqalzYEw842ad1H1ZvvfybFZXvyEs5zeKb8uZM SFKKH7kRD2e6KmSTwBozRsz3PFhhE4VLpWTmnICM2WfUrGTwna0cFFWg5Z35pFLdGKJG hhMTWCSbxXC1DfrAY4x76/3OgMgqyFOdfHxsMsceGo4GnwjdRTUXATt0NvFMJezlmJc6 Ij+gxI3E79wNAKSKynng5suDzGwmVjbOhTVELHNVMjIV8Nq63QW2ioSpIuApKMhb9qq5 F1174VZM7deep3nTZqJCG2kvX5xpn5pwylFBEDGZL/O8CN8k0l17i+69xQiJU/7auvs0 CDXA== X-Forwarded-Encrypted: i=1; AJvYcCVrXOx52FjLEi45qwOLN5EP5IslBW5FfHeZn/F5pKv/bffC4YEjxVlZHrp4PYavlrF3ZT1J34u70GKv+1fpzg==@vger.kernel.org X-Gm-Message-State: AOJu0YykaZz8xAJ0To0yyT0X07YQQxh28D2YDonwQ8H3XBANaNEg58vt PyxZ34Ybr4cY7zqJnChNhY42xqDOrugfojuz/+jG5cAzacarUTLfMjYwfEAUcxTTTNcXycxomOl wnmmjDRCMq7lRHkKASw== X-Received: from wmby1.prod.google.com ([2002:a05:600c:c041:b0:47e:ddf0:fd00]) (user=aliceryhl job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:35d2:b0:477:b734:8c53 with SMTP id 5b1f17b1804b1-4801eabf1c9mr75158475e9.12.1768656567159; Sat, 17 Jan 2026 05:29:27 -0800 (PST) Date: Sat, 17 Jan 2026 13:29:25 +0000 In-Reply-To: Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260116-rcu-box-v1-0-38ebfbcd53f0@google.com> Message-ID: Subject: Re: [PATCH RFC 0/2] rcu box container for Rust + maple tree load_rcu From: Alice Ryhl To: Boqun Feng Cc: "Paul E. McKenney" , "Liam R. Howlett" , Gary Guo , Miguel Ojeda , "=?utf-8?B?QmrDtnJu?= 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 Content-Type: text/plain; charset="utf-8" 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. Alice