From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f180.google.com (mail-pl1-f180.google.com [209.85.214.180]) (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 EB88F224898 for ; Wed, 19 Mar 2025 02:26:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.180 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742351211; cv=none; b=jhvkOmFj4iKjoPjM6ZSCyBxRLXQpc5ArW2M2qh6lAAMbdUuEDdnGBU+QcYrTrpAU4bhVjMechy+gSWMQsLvhpVQIxG0lfNTvWEU5xVHHSh47axdqMEIwFWxs728B42t5ZsnGWk3VofJxGp8/HslamjD1PfFPdfNuK5w78nXJaKE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742351211; c=relaxed/simple; bh=7ndRtF44IDuR/Iw9NUnpMKfPJB5kK3QTMCwjXmKrW38=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=XU+u37BrKQCbcQH3jMs7hQGJ4IzlWWTNRU2vth8pRkQfzVf7WMwiKsJTd3CoJd0comILdpYWepjKuZ9zS4zvQlxJGXkzbo1R3+MzZqjzkeSiCpy6G29aMKmiyoBKTadksTQKFLt4yE0tp+6ThBqQVd1PudGh1X2WocnuzrHLvrk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Psc9lWJw; arc=none smtp.client-ip=209.85.214.180 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Psc9lWJw" Received: by mail-pl1-f180.google.com with SMTP id d9443c01a7336-223a7065ff8so31171345ad.0 for ; Tue, 18 Mar 2025 19:26:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1742351209; x=1742956009; darn=lists.linux.dev; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=AbIHvmmG5js1PLHp8uTT6TGLBU5cpAS+qD/HRwri4Ls=; b=Psc9lWJwOzy0f7kDb74Oxwp7E7dyFkKw/QF/OMHnR9GlXTWpCUWzQ3SFBQFukPiMpt 9HzgVwJ7pFQhsUPaGs3GFGwiM7OetVBXWjHsiHRvtM2uMZd1r/r+uFnkDfJ43PDDIFBF sx6T3UZ/F+7OdI8I3DNiWUNmN5oiMLyBI9PRSUclxyqAYNEtes73KI0OcBvvbcJLnz7j VTGKNHlcSixdnE2hGBrMibK+V6KXriUOysg2ddAISZl5onaUyL8N3P5NqchcrDLIjLhx BvQpoJeiQ6Y+oMXvjlg7c+jSaYcsaMGYfrXBRvdrPj8R+LZpWzx0rEFpYlaUPbxqM2wl hBeQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1742351209; x=1742956009; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=AbIHvmmG5js1PLHp8uTT6TGLBU5cpAS+qD/HRwri4Ls=; b=FCYTrmwi9Qkl1pN41n7T9WBctHYT0hBzK+fn9ne934bJCW7eIV6Osk372ltQrgJKJA llqZJvHfUpletTFP/N/aF8u6rgX3A2EozQ4RkvOcuUOyqv+16O9palTqlrrGe4+/DeTd nNBxqV/WQQ96kyonAbAERw1+pAemCjrRFPUYZQrlwTZyl9T/gtpnx3wRJXg7C2+7sQ2a /3hv6e2Iz8WKESITMYF7uGDsaU7WNTF6H5bdYV3w2cVKhiy0faIaRI930dqkct2fM2js mojI3/M+fUvAQFW6IzZZsygYYW6cF5XwHP5Bgh5mKUoRv88/Z+PWPx1DhkSSS1pI9rJr Tkow== X-Forwarded-Encrypted: i=1; AJvYcCUae1jU8WmhOsy6nv1Ea7aH031E++xPlKQO6LxYsCmQ/JV1yLoEZHTOsIUqvfpFxkw5AOA+gmBLci7bGpBv0EaDQUkNZg==@lists.linux.dev X-Gm-Message-State: AOJu0YziaiCHYIuBw5NPe1yHTG071frl51Z5H/+KNM171w5UB8w0g9z3 Z15dQTzdDzi36aOmjIOJ5mPELDEHbmcqgqyCYJ9tMjuv9k/ozwRm X-Gm-Gg: ASbGncv2um9F/iiHbmkRXQpQjQwHJc7iAhDqKIICLbwEYrT7RLre/qUYr7GDwTVO5I7 mqEGeGeih/FulvUErsWm6a4U6z9km111RdU3JiUBUTh9LSzqQRTI84LQ+0pIedLVO2yCYTIKCzj aUkrSo9cljU9MmD/1j8DLdM1c2OV6UlsJ1fd/HeP2yrWWe9AE4y+xE1IrCfo2Y1lHltct5oR8Wp kkg3V4UeeZd7IOs8Z4oqCBJJi6JmTGtQmK3uPoyuvW5kGAPY2ZdgXXUr3B/WRcGrYISop34ygHL 4f/ouzf7jqaPCG6EKfLf44xWTX7QdSIBthEckxxPxpiRX1PNRwd+gFSD4yApSL6UedXOuDjlzy0 = X-Google-Smtp-Source: AGHT+IHZ9BD8ZaOCOCQgXrEkiiKdJlyV+ramk5NngA/ynv6mcMiXCm7l3udoK9awSQXYb3itTUtvKQ== X-Received: by 2002:a17:903:292:b0:224:1001:677c with SMTP id d9443c01a7336-2264981eb43mr15517845ad.9.1742351209081; Tue, 18 Mar 2025 19:26:49 -0700 (PDT) Received: from vaxr-ASUSPRO-D840MB-M840MB.. ([2001:288:7001:2703:35d0:8dad:cfe4:6cb9]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-225c68a406fsm102788585ad.64.2025.03.18.19.26.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 18 Mar 2025 19:26:48 -0700 (PDT) From: I Hsin Cheng To: rostedt@goodmis.org Cc: paulmck@kernel.org, frederic@kernel.org, neeraj.upadhyay@kernel.org, joel@joelfernandes.org, josh@joshtriplett.org, boqun.feng@gmail.com, urezki@gmail.com, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, qiang.zhang1211@gmail.com, ojeda@kernel.org, alex.gaynor@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, a.hindborg@kernel.org, aliceryhl@google.com, tmgross@umich.edu, dakr@kernel.org, rcu@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, skhan@linuxfoundation.org, linux-kernel-mentees@lists.linux.dev, jserv@ccns.ncku.edu.tw, I Hsin Cheng Subject: [PATCH v2] rust: sync: rcu: Mark Guard methods as inline Date: Wed, 19 Mar 2025 10:26:40 +0800 Message-ID: <20250319022640.970207-1-richard120310@gmail.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel-mentees@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Currently the implementation of "Guard" methods are basically wrappers around rcu's function within kernel. Building the kernel with llvm 18.1.8 on x86_64 machine will generate the following symbols: $ nm vmlinux | grep ' _R'.*Guard | rustfilt ffffffff817b6c90 T ::new ffffffff817b6cb0 T ::unlock ffffffff817b6cd0 T ::drop ffffffff817b6c90 T ::default These Rust symbols are basically wrappers around functions "rcu_read_lock" and "rcu_read_unlock". Marking them as inline can reduce the generation of these symbols, and saves the size of code generation for 132 bytes. $ ./scripts/bloat-o-meter vmlinux_old vmlinux_new add/remove: 0/10 grow/shrink: 0/1 up/down: 0/-132 (-132) Function old new delta _RNvXs1_Cs4gouIKNZ4iT_15rust_driver_pciNtB5_12SampleDriverNtNtCsaYBeKL739Xz_6kernel3pci6Driver5probe 1041 1034 -7 _RNvXs_NtNtCsaYBeKL739Xz_6kernel4sync3rcuNtB4_5GuardNtNtCsdaXADs8PRFB_4core7default7Default7default 9 - -9 _RNvXs0_NtNtCsaYBeKL739Xz_6kernel4sync3rcuNtB5_5GuardNtNtNtCsdaXADs8PRFB_4core3ops4drop4Drop4drop 9 - -9 _RNvNtNtCsaYBeKL739Xz_6kernel4sync3rcu9read_lock 9 - -9 _RNvMNtNtCsaYBeKL739Xz_6kernel4sync3rcuNtB2_5Guard6unlock 9 - -9 _RNvMNtNtCsaYBeKL739Xz_6kernel4sync3rcuNtB2_5Guard3new 9 - -9 __pfx__RNvXs_NtNtCsaYBeKL739Xz_6kernel4sync3rcuNtB4_5GuardNtNtCsdaXADs8PRFB_4core7default7Default7default 16 - -16 __pfx__RNvXs0_NtNtCsaYBeKL739Xz_6kernel4sync3rcuNtB5_5GuardNtNtNtCsdaXADs8PRFB_4core3ops4drop4Drop4drop 16 - -16 __pfx__RNvNtNtCsaYBeKL739Xz_6kernel4sync3rcu9read_lock 16 - -16 __pfx__RNvMNtNtCsaYBeKL739Xz_6kernel4sync3rcuNtB2_5Guard6unlock 16 - -16 __pfx__RNvMNtNtCsaYBeKL739Xz_6kernel4sync3rcuNtB2_5Guard3new 16 - -16 Total: Before=23365955, After=23365823, chg -0.00% Link: https://github.com/Rust-for-Linux/linux/issues/1145 Signed-off-by: I Hsin Cheng --- Changelog: v1 -> v2: - Mark read_lock() as inline as well - Fix typos --- rust/kernel/sync/rcu.rs | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/rust/kernel/sync/rcu.rs b/rust/kernel/sync/rcu.rs index b51d9150ffe2..a32bef6e490b 100644 --- a/rust/kernel/sync/rcu.rs +++ b/rust/kernel/sync/rcu.rs @@ -17,6 +17,7 @@ impl Guard { /// Acquires the RCU read side lock and returns a guard. + #[inline] pub fn new() -> Self { // SAFETY: An FFI call with no additional requirements. unsafe { bindings::rcu_read_lock() }; @@ -25,16 +26,19 @@ pub fn new() -> Self { } /// Explicitly releases the RCU read side lock. + #[inline] pub fn unlock(self) {} } impl Default for Guard { + #[inline] fn default() -> Self { Self::new() } } impl Drop for Guard { + #[inline] fn drop(&mut self) { // SAFETY: By the type invariants, the RCU read side is locked, so it is ok to unlock it. unsafe { bindings::rcu_read_unlock() }; @@ -42,6 +46,7 @@ fn drop(&mut self) { } /// Acquires the RCU read side lock. +#[inline] pub fn read_lock() -> Guard { Guard::new() } -- 2.43.0