From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f73.google.com (mail-wm1-f73.google.com [209.85.128.73]) (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 00F573191DE for ; Sat, 17 Jan 2026 13:29:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768656571; cv=none; b=Bh8hlt16JcbsSAkja6ocPdVAjS3Wv36d+niFO0pY8aNMM8UzTKQ/btZBxHbc8KGnWPPhET+jZTWVvvwzREtNUJ/DgQQQ9XA1I/WFtL7vA4KaC8wz5p7sge8ZJWvTBO8gw/KeiS9sL5fLJLyhwb/5NufkGVuYPIqeVKvB1chXWNQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768656571; c=relaxed/simple; bh=yGX0/BmN4QSqMec6LsJaLEgukSwhg32D3RH18NXGaE8=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=huvyMnAJGAMtknxT6o7xfyeCPVPcioV5eBxSj6nRW62oNZYNb21CtgRm/YZbY3rzDMC8Ius5F+Ufc2WqLmvU3X6teZRYSUiOdpOuJt4VvPwM9IZhf1Mq83pddtXdFTkA3s7R0y8H//vaf+qoAsh/b0zyFq1OVh578ViZDH331jA= 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=209.85.128.73 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-f73.google.com with SMTP id 5b1f17b1804b1-47d3ba3a49cso31527495e9.2 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=aV7AvPRaRCMRf+OqpiLgDWySEXcDQqWFd37DOAvT/P+UmcAoxuFwQKDIm6JIehKvHK wTY+KsYx9+QVKocM18fb3wq0FpvzcdrURnMpzZt1ICsXmiULPAcjxxBmqKpXv3KLu8ef sltmtDKdwV2w/L6rPQHKw5qYNS8/8qHdgqgF3d7Z22/dzTxRR8xzDLZ5ZUeazFIuYuy+ egc7b9OweSUarfav1JKF8xxz6KkcU6prr90beNtip+z2wxAM+ZzZ0VgkVrhQ8VuM9pyF 55Oy9QMlh/p9iPsXuZsT/iaY3q6YljXq9e/JC4D3ZMrvnPZUJSnLhyzaC0C9e3W1XzUt hbeQ== X-Forwarded-Encrypted: i=1; AJvYcCVDJKcXU2JLf5q9D8ZvVDiK2Jahi3tCQykm1WDUQ2xsWxA+PfQfRv/spTkWg4mUU1sWRng=@vger.kernel.org X-Gm-Message-State: AOJu0Yw1+j/wFIPaWicyywfrqOMaGOseseg1o/89L0nmXXTgQowjucRY XwZ0FZtU+ufbIj7JoFOz+JCDlPm3+zoy5MR63/fGmAB1TdviQSZfU6KRLIPDvUmlFn1CuyE+irK V3TY/Y8JI1xvOUHBe+w== 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: rcu@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