From nobody Wed Oct 8 17:34:00 2025 Received: from forward205a.mail.yandex.net (forward205a.mail.yandex.net [178.154.239.88]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E92C92609FE; Wed, 25 Jun 2025 13:48:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=178.154.239.88 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750859323; cv=none; b=OMKMbf+glk0SPVqM0QuNLuz27/kv0uzQtlf9ntU/+rSk+febBrTAUjnIjrWBH3ZwGwKVZLrBkAZvmA1FjP+p2O6wIPTQE4gzwk/Du3RE3Cn5xUe6+TSKKqsLMifq3B/spL//kIe2YrD22X20oTOqf1PBmCxitwI0zqczu/es2rQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750859323; c=relaxed/simple; bh=DyWGO5uV4iCKw39gngTGRWlylzt8jhIu7LFkwE5ZtTQ=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=Sny2igRCiqh5lQkqDfN+3N/a30nwtKvEsROSaDE1a+8oFpskLwyrQWesdJVD7gZG0PPESM+wAs2JeUSAh6KyCyCUjjzrFmT6WJ0pO5YdiZ9/2LCcA08hHV1jnthyqsVm6+EcoLH5GbpMBQHDBHHVS8n/5CfbWwdTkpVKOvifRTE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=onurozkan.dev; spf=pass smtp.mailfrom=onurozkan.dev; dkim=pass (1024-bit key) header.d=onurozkan.dev header.i=@onurozkan.dev header.b=R0mqvmH1; arc=none smtp.client-ip=178.154.239.88 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=onurozkan.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=onurozkan.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=onurozkan.dev header.i=@onurozkan.dev header.b="R0mqvmH1" Received: from forward100a.mail.yandex.net (forward100a.mail.yandex.net [IPv6:2a02:6b8:c0e:500:1:45:d181:d100]) by forward205a.mail.yandex.net (Yandex) with ESMTPS id 8BBC865E23; Wed, 25 Jun 2025 16:43:08 +0300 (MSK) Received: from mail-nwsmtp-smtp-production-main-59.iva.yp-c.yandex.net (mail-nwsmtp-smtp-production-main-59.iva.yp-c.yandex.net [IPv6:2a02:6b8:c0c:90a4:0:640:a790:0]) by forward100a.mail.yandex.net (Yandex) with ESMTPS id E3F8C46DAE; Wed, 25 Jun 2025 16:42:59 +0300 (MSK) Received: by mail-nwsmtp-smtp-production-main-59.iva.yp-c.yandex.net (smtp/Yandex) with ESMTPSA id lgUwmHwLk8c0-3DNayexY; Wed, 25 Jun 2025 16:42:59 +0300 X-Yandex-Fwd: 1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=onurozkan.dev; s=mail; t=1750858979; bh=/JZa2/ArvXobd5bldiwnQiPtvCokwDkARdf/6PiesIk=; h=Message-ID:Date:Cc:Subject:To:From; b=R0mqvmH1n4uADigUZOnT/dFs7fn8NVPXt7ofLV6oZBzNzljMwVcvs2XLUrXdZINMp AbHXsh2nvezqLdGLT/v3V4YWv/zeaAJhbWnwddsma3w2JBFyPqPLvR4oG2XJ7W0RSL 8pzZYGGGI6x1mM0ky01m55j0a4pG2rgjs7dHCU1E= Authentication-Results: mail-nwsmtp-smtp-production-main-59.iva.yp-c.yandex.net; dkim=pass header.i=@onurozkan.dev From: =?UTF-8?q?Onur=20=C3=96zkan?= To: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org Cc: ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, lossin@kernel.org, a.hindborg@kernel.org, aliceryhl@google.com, tmgross@umich.edu, dakr@kernel.org, mattgilbride@google.com, wedsonaf@gmail.com, tamird@gmail.com, daniel@sedlak.dev, =?UTF-8?q?Onur=20=C3=96zkan?= Subject: [PATCH] rust: add fast path to `RBTree::find_mut` for empty tree Date: Wed, 25 Jun 2025 16:42:45 +0300 Message-ID: <20250625134245.14505-1-work@onurozkan.dev> X-Mailer: git-send-email 2.50.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Adds a fast path to `RBTree::find_mut` that immediately returns `None` when the tree is empty. This should also benefit `RBTree::get_mut`, `RBTree::remove_node` and `RBTree::remove` functions as they rely on `find_mut` internally. Signed-off-by: Onur =C3=96zkan --- rust/kernel/rbtree.rs | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/rust/kernel/rbtree.rs b/rust/kernel/rbtree.rs index 8d978c896747..a9b79b22ea32 100644 --- a/rust/kernel/rbtree.rs +++ b/rust/kernel/rbtree.rs @@ -365,6 +365,11 @@ pub fn entry(&mut self, key: K) -> Entry<'_, K, V> { /// Used for accessing the given node, if it exists. pub fn find_mut(&mut self, key: &K) -> Option>= { + // Fast path: return `None` when tree is empty. + if self.root.rb_node.is_null() { + return None; + } + match self.raw_entry(key) { RawEntry::Occupied(entry) =3D> Some(entry), RawEntry::Vacant(_entry) =3D> None, -- 2.50.0