From nobody Thu Oct 2 15:16:48 2025 Received: from mail-pg1-f175.google.com (mail-pg1-f175.google.com [209.85.215.175]) (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 04D062ECD1A for ; Tue, 16 Sep 2025 04:49:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.175 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757998177; cv=none; b=HX8EC3vwqIx6bWRLOZooIa9rdORDO074u0oazOE5EYkJmB2FvemEA+Wv+7TfsBw778ryRxRofWJ5ZNHvMRXAvtPvD6BMCxj0mNxxcoPRn7wSvDjAL0/vwrhBWmwcNoP6SeVAKJyMVIRU2Z5f/bFW5f8kJ/FzdC+oH7ondMvYnc0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757998177; c=relaxed/simple; bh=dy9spvLipBJ0oxpRy6D3U8JeqM1cA+2DUbEARoiEIho=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=rXd9KQ6yVxNQPOZs9OBHXISEemHeFpgK5W4Ka8MM4CAIL+lW9r/eatNds5Uv1M7LwpU1DsiNLxcvTzRSv0CZsyKNYLV1QOPI8zdh/xNCsK9nKPypzDcY9Jhct3M5FTU9sGR6XnZaAENFtscOZZ6MOTFpRFxg1Is8hff7HJVhLww= 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=WEJwboRo; arc=none smtp.client-ip=209.85.215.175 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="WEJwboRo" Received: by mail-pg1-f175.google.com with SMTP id 41be03b00d2f7-b54d23714adso1207003a12.0 for ; Mon, 15 Sep 2025 21:49:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1757998174; x=1758602974; 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=kee/jWM05xMj5MjToYK8a9EUY/mguZ7xPQQnB3cJ53E=; b=WEJwboRoA+7Q/dtbpjLY1iSOzyDv2c7nLD5tzESh/xoo13VNtR/TuEemvpBow5vvEn H7ry4eNsUi4IQV8DjKDpbV4r0L5NEiNdbzxgZ9uF1g6TLnrD4vmU5xiiUDdvRUp82yHX 5XmgyQKs33tjnmDUjMrqxpFjpFB6RPqKiIYNPBfImWxQHKjvIJQIuhSjg3OwcMtI6Sfo i4HnREvhWsFyA7lO140ZMwL9JUpp5QX2ZSunJSuv006RmJnQTtQVVYSSc8waQPaTuRg6 2dO06Xyt+iuxUmp3SRacsW6eS/lXTsOf7kwLF/UWzELlusoGLpEM/leXstF1sKj4podi n90w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1757998174; x=1758602974; 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=kee/jWM05xMj5MjToYK8a9EUY/mguZ7xPQQnB3cJ53E=; b=tP0tno6Cv3HPgeFN52+O1j7mS9yv6cWmVSz8T5wDzRRZeU8IjszmaB+33LceiFMq8A X5B0O8g2q0L5NlwmDh8fa8ahQTdjV3pDnXP6sOW6RnmPqakECMFcYAgYSlkwwZlsRapS /uqvux4VcazZu23WY2EoZGewyi49v/hXbamR+oFwITddIEeMm7awK+RC3Z7R78hywWzp ibMOpXcIu/lwg6HYP3VkU5rKKxQhvs7k+Q+GTkx2M71RVQnxIn7K0AWoilAz/lF596h7 wYljCGojsU5lADqYT/YV2Y3FGkx86uPgs6uSvcZ9DpCMM37EdahcwLMjyCO9icFaaVOz jrgQ== X-Forwarded-Encrypted: i=1; AJvYcCUTXAri9GNYDLZPc7m1r4DFy/f7JjrmkR4giWQKTAo8qCZ0hX+5+KznonWrXxLxLL2qVdvtoAd6VFzmtSA=@vger.kernel.org X-Gm-Message-State: AOJu0YzTN0EkP8BEN0JYOyVBZ8O3B1pS/fhBI3u+iiffWXPpZMT+vni6 dnq7Ns8rPgmHtRHGIQ/n6BXrtKHeuMwnp8YivnXmP18JLRbJQryvdatj X-Gm-Gg: ASbGnctu15o1AK5L3T+qdmg3EHdVneF3RmvnkAIqsp2AaiBbxGPn6Jvjy7R0PKq5dw2 YLa/v1PhbUwE3XtX9mnmRFNVj5e12iwJrrqdiWxBAJy3pOFqMSn+7oTmxaS5h+VRY5w34HAZ/Hf 8KjRn3GOiuC/2K9piym++7dVNadUzrB20e3oJYNc6dPoI0nj4VrsQ+p4TxGXOtTqzpfWLVve0Y9 WuT4iBK4nD/g7yn76ezG+6yBdxG1Mhvj3A86DXvqp3Wgh/KEgd8Rb/17d1O7qvXvkYc046yxXR4 0t+azxXQqDJbkzG21tR++IEX++9Qt1PVRtOLC8mga5qffkfPKaFrphvvibxg9KyXXnTfH6LE1QN 9c3Lm+G2ueJg3/rf+63BYB48/7F1fMZDNY//tOuo= X-Google-Smtp-Source: AGHT+IHQsp/jp2h5qh/u2y0fwJLYw3kUJFgybrRxf3n883LnUrw88kxlxQMidQOFwo4KtZaOVgbKQg== X-Received: by 2002:a17:902:cecc:b0:267:a1d5:7372 with SMTP id d9443c01a7336-267d151fba1mr14211985ad.4.1757998173983; Mon, 15 Sep 2025 21:49:33 -0700 (PDT) Received: from pengdl-pc.mioffice.cn ([43.224.245.249]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-25ef09c77f8sm104600605ad.15.2025.09.15.21.49.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 15 Sep 2025 21:49:33 -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 , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , pengdonglin Subject: [PATCH v3 12/14] net: amt: Remove redundant rcu_read_lock/unlock() in spin_lock Date: Tue, 16 Sep 2025 12:47:33 +0800 Message-Id: <20250916044735.2316171-13-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-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: pengdonglin Since commit a8bb74acd8efe ("rcu: Consolidate RCU-sched update-side functio= n 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: Taehee Yoo Cc: Andrew Lunn Cc: "David S. Miller" Cc: Eric Dumazet Cc: Jakub Kicinski Signed-off-by: pengdonglin Signed-off-by: pengdonglin --- drivers/net/amt.c | 8 -------- 1 file changed, 8 deletions(-) diff --git a/drivers/net/amt.c b/drivers/net/amt.c index ed86537b2f61..aaed9fbc7526 100644 --- a/drivers/net/amt.c +++ b/drivers/net/amt.c @@ -295,7 +295,6 @@ static void amt_source_work(struct work_struct *work) =20 tunnel =3D gnode->tunnel_list; spin_lock_bh(&tunnel->lock); - rcu_read_lock(); if (gnode->filter_mode =3D=3D MCAST_INCLUDE) { amt_destroy_source(snode); if (!gnode->nr_sources) @@ -306,7 +305,6 @@ static void amt_source_work(struct work_struct *work) */ snode->status =3D AMT_SOURCE_STATUS_D_FWD; } - rcu_read_unlock(); spin_unlock_bh(&tunnel->lock); } =20 @@ -426,7 +424,6 @@ static void amt_group_work(struct work_struct *work) goto out; } =20 - rcu_read_lock(); for (i =3D 0; i < buckets; i++) { hlist_for_each_entry_safe(snode, t, &gnode->sources[i], node) { @@ -443,7 +440,6 @@ static void amt_group_work(struct work_struct *work) amt_del_group(amt, gnode); else gnode->filter_mode =3D MCAST_INCLUDE; - rcu_read_unlock(); spin_unlock_bh(&tunnel->lock); out: dev_put(amt->dev); @@ -1327,11 +1323,9 @@ static void amt_clear_groups(struct amt_tunnel_list = *tunnel) int i; =20 spin_lock_bh(&tunnel->lock); - rcu_read_lock(); for (i =3D 0; i < amt->hash_buckets; i++) hlist_for_each_entry_safe(gnode, t, &tunnel->groups[i], node) amt_del_group(amt, gnode); - rcu_read_unlock(); spin_unlock_bh(&tunnel->lock); } =20 @@ -1343,11 +1337,9 @@ static void amt_tunnel_expire(struct work_struct *wo= rk) struct amt_dev *amt =3D tunnel->amt; =20 spin_lock_bh(&amt->lock); - rcu_read_lock(); list_del_rcu(&tunnel->list); amt->nr_tunnels--; amt_clear_groups(tunnel); - rcu_read_unlock(); spin_unlock_bh(&amt->lock); kfree_rcu(tunnel, rcu); } --=20 2.34.1