From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f169.google.com (mail-pg1-f169.google.com [209.85.215.169]) (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 85BB72D6E7D for ; Tue, 16 Sep 2025 04:48:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.169 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757998111; cv=none; b=myFzA5QbnOmo/7nElmnKMZfEqUaUFMdvaRGLB29sPkYfOIpdwyFR9jTZcE8wcu7E1Wn1kEC//rMbVFTKR1itD/M8SFS7ns37/C9ZR0opq9dlA6nfTmYjN+1ombcRWeypE67lieXFLIB0g5TSnoYXfQo8pj/pPSGRUO0zIUyX1nQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757998111; c=relaxed/simple; bh=ja+bbJPbRSrQwDXA6/q8IikecZ6d8Rw7OMDfeYI0NFk=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=gDk77YDvcGvA1lPDkdWqO6B6bVuPzLRwMeMngd75CiMlGqDpYhc786Jtd3gtlpXshWPKjzsGNiQla4ugr0cOjB5XcuAJBzv6AMf35TzqqbtctWGAqh5IWB7dzB292Uj8K2n+rX9DwJsjVTrNZ4bjNmt+SPH6bxrMzxezv0TGSZw= 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=Fkm2iDgr; arc=none smtp.client-ip=209.85.215.169 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="Fkm2iDgr" Received: by mail-pg1-f169.google.com with SMTP id 41be03b00d2f7-b4cb3367d87so3290314a12.3 for ; Mon, 15 Sep 2025 21:48:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1757998108; x=1758602908; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=E4GnwUXvg4e1SjHBDj7IOnsANmiVf/8g2S4TikZ2k4g=; b=Fkm2iDgrcPVBuaesrw7FvVYaF9dMzh7OYHeK4JX3EgxQ++R33RT7gwSxXKWspg2bZz 5FOFvJ9AkTWPvAhIegP4B+Vj0Gy+5liVRyC8yoicuKPE5FKhfmFF8b8qV0G+MVzpCmms 4qfEPXAE3lymVWIuTtXVTadXIAI1bFHNZBRgjs69h3p8XbsTTNKEC7MjRXJjx38eAhgc zaoIwDnkLZSXNeCZxzCz630o7NNmGpGKTQrdgbdy1CKScwc/89o++bjOv83NkYZeXeTq FO51pCkeizUOyu86k/oKP//hAvAEpA9Za35Q8X5WtgOWGeoJmw9MQI/icPPvrJpZWAX+ n2Ag== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1757998108; x=1758602908; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=E4GnwUXvg4e1SjHBDj7IOnsANmiVf/8g2S4TikZ2k4g=; b=ecsOOT/DSpZerM7ikbq+K9+0CAQPdLqUHxA3lz38rvY6HHc03K33qWIbtdpcOOeX+F PTBbK/bVM0okNYJHFIxsNYTmlRrTTFhxmTuqca2lrIwrYy+xKkJtKbHqccek4d9UyaXz 9aFMGnXwUVfYzVb2Qq3pE24biF4XFGGOnSSQvujrdUSldAFNwOncWoKkOkXUB7WZiD1h 0NHxkAu9GPbVvzvydH3MmwkZFnKsGX9FeJDOtIhuCpl5m7uvcz8d5lHdG7QLRVXem/9e /5bpRenJsZDrSTHkFI97iU+E0WoK+RVg68OjdpLEobZKF6EV7Vy6NnjNRnTxZQpRb5fD qAnw== X-Forwarded-Encrypted: i=1; AJvYcCW/OUrrXITm3B8FKcLpn9bTjI4N1aNL0iObmS2KGwNhUFp+ylWhEVdxh/N7Gqn7wqGzsfNoQ6Zk8kJF@vger.kernel.org X-Gm-Message-State: AOJu0YzUGaahtM58Vb77PAXPw5CrntS3Ed1M8zWPdzzmkADKuxAEO9cF ni56q3SquQV5MK2wgiQHfh3Q6AfHRpSIkgaIQAW1MY+56H2zRRDse7we X-Gm-Gg: ASbGncuf2pU7u++uDpbYPTRGbo+eRhMepX8TjD+9glNtrUW55RZfTgbNKL+kJI02+xE ouv7lysoLZIVpXFmnILQ/897gwo26HkAMG5YUFCKX8C2jtZPtEu7CUfgUOTOPAjm29mTdKUhIff MNlfaO6rosDNKK1So4jc/Pi96qc+CV/GoN2WeNFfUk3gos3AqP6k0ca3i/PAp0s0ccRY7QvN6xQ CGVVVr53+PsSb6Or3IOZ9a6wMTBE9h6QwmFryKKVq8gELaBp8kWVtmb8n1stVWiIrBgZJ3qqQvU BHM890Cva7AZWIuwfcSdFtFIv4ifeDcAZ4BbQ0kyrA+9zRmW1NKmzcU5FbpxOBNJRXjaNxhH36L qvMd2QVlEZ6sXUhlABcnzPOb4Z65ilSy5uZnmJhQ= X-Google-Smtp-Source: AGHT+IEX+DuJO9pqL+sh6jlOJbx2wPh/MnPUcew7z+h1RxAPsxkAl191gDKewoy1JkBZ+L5tKb1L0g== X-Received: by 2002:a17:902:ec8e:b0:25d:d848:1cca with SMTP id d9443c01a7336-25dd8481fbdmr195481725ad.35.1757998107572; Mon, 15 Sep 2025 21:48:27 -0700 (PDT) Received: from pengdl-pc.mioffice.cn ([43.224.245.249]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-25ef09c77f8sm104600605ad.15.2025.09.15.21.48.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 15 Sep 2025 21:48:27 -0700 (PDT) From: pengdonglin To: tj@kernel.org, tony.luck@intel.com, jani.nikula@linux.intel.com, ap420073@gmail.com, jv@jvosburgh.net, freude@linux.ibm.com, bcrl@kvack.org, trondmy@kernel.org, longman@redhat.com, kees@kernel.org Cc: bigeasy@linutronix.de, hdanton@sina.com, paulmck@kernel.org, linux-kernel@vger.kernel.org, linux-rt-devel@lists.linux.dev, linux-nfs@vger.kernel.org, linux-aio@kvack.org, linux-fsdevel@vger.kernel.org, linux-security-module@vger.kernel.org, netdev@vger.kernel.org, intel-gfx@lists.freedesktop.org, linux-wireless@vger.kernel.org, linux-acpi@vger.kernel.org, linux-s390@vger.kernel.org, cgroups@vger.kernel.org, pengdonglin , Joonas Lahtinen , Tvrtko Ursulin , pengdonglin Subject: [PATCH v3 02/14] drm/i915/gt: Remove redundant rcu_read_lock/unlock() in spin_lock Date: Tue, 16 Sep 2025 12:47:23 +0800 Message-Id: <20250916044735.2316171-3-dolinux.peng@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250916044735.2316171-1-dolinux.peng@gmail.com> References: <20250916044735.2316171-1-dolinux.peng@gmail.com> Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: pengdonglin Since commit a8bb74acd8efe ("rcu: Consolidate RCU-sched update-side function definitions") there is no difference between rcu_read_lock(), rcu_read_lock_bh() and rcu_read_lock_sched() in terms of RCU read section and the relevant grace period. That means that spin_lock(), which implies rcu_read_lock_sched(), also implies rcu_read_lock(). There is no need no explicitly start a RCU read section if one has already been started implicitly by spin_lock(). Simplify the code and remove the inner rcu_read_lock() invocation. Cc: Jani Nikula Cc: Joonas Lahtinen Cc: Tvrtko Ursulin Signed-off-by: pengdonglin Signed-off-by: pengdonglin --- drivers/gpu/drm/i915/gt/intel_ring_submission.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_ring_submission.c b/drivers/gpu/drm/i915/gt/intel_ring_submission.c index 2a6d79abf25b..bf73166a1337 100644 --- a/drivers/gpu/drm/i915/gt/intel_ring_submission.c +++ b/drivers/gpu/drm/i915/gt/intel_ring_submission.c @@ -392,14 +392,12 @@ static void reset_rewind(struct intel_engine_cs *engine, bool stalled) rq = NULL; spin_lock_irqsave(&engine->sched_engine->lock, flags); - rcu_read_lock(); list_for_each_entry(pos, &engine->sched_engine->requests, sched.link) { if (!__i915_request_is_complete(pos)) { rq = pos; break; } } - rcu_read_unlock(); /* * The guilty request will get skipped on a hung engine. -- 2.34.1