From patchwork Tue Apr 1 16:34:48 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanislav Fomichev X-Patchwork-Id: 14035154 X-Patchwork-Delegate: kuba@kernel.org Received: from mail-pl1-f181.google.com (mail-pl1-f181.google.com [209.85.214.181]) (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 144EB20E313 for ; Tue, 1 Apr 2025 16:35:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.181 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743525306; cv=none; b=b1vIuUMWHJVT6HDgoHaWCwMxo/Ri8gdotYPAZ8YwdQfqBO7w9oqeq4O+hxleVRXNh8kH1ZJCFd8hoCSeHxOuBTD9S+fAsaO6ZnAUi8SbwWBvJQvS0L1gHU6+RVlH74mJf6jMkjYdqe1WYdgy4IoMblGO4iByxpHdRbnUiscU/vI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743525306; c=relaxed/simple; bh=brNcDKtIpW55d45qQoDg2xLCrtCFSoB36qUcpPmbkBc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Yzr710LcjuPsIqR0ClG1p52IzWGHxfWO5iK/Dd34MUj+wYX4MxfxOpSPnizlqlOB0YQW5Jpdvg1BPgmuGM9M6er7uYxQZlOz9Hd4NK8lRij8hck1FoETgtLXrazr1TpJvYJQeQ0dW5KY0NkNz9YAVsHj+QCbooXZnUD4tnI5Hvc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=fomichev.me; spf=pass smtp.mailfrom=gmail.com; arc=none smtp.client-ip=209.85.214.181 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=fomichev.me Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-pl1-f181.google.com with SMTP id d9443c01a7336-2254e0b4b79so149100405ad.2 for ; Tue, 01 Apr 2025 09:35:04 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1743525304; x=1744130104; 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=hV36hiRVRFzZxgV3bV0iMgv0RNkvHa9U+49mMjCNugs=; b=ROIr1bSkTEXFvI9YOI3WuXa++fd7El7TVxNI0kK8wnJmXAQEJ0K6Hg19+5dmhBe1r7 LA1K8wNYm+oMHJlOSdtbL4Huc/vB+u7/MG+Hu9d6PJepiSwjec3bFO3D0GO3BwUvdV4u S8SlGxL1toe0FPmZpgpF+wIYsqaowUoAeqzdZNbziZNvcm4k7IT/ixFi3dXQiOyM7xcl Po+nGZa9wu3vA573+ELvyuqfWAv9hKpoJHav1d+shvF3Sp1Q9U3TnnV9XLS1XRvWNAgl KNXk64L4rtUGBGxdLvzjtBKd7XC45B10Kwoy3ktbaVeyw8rYNdGr+AcQsMPt1UfoLxHQ u1Lw== X-Gm-Message-State: AOJu0Yw3nCxc87KM9x24EApfC89qv6rw6lU3bD0qS/yl8OHix1dFbA+D cYrcjhPojUGPCq4v+Q+YoitMm0RPGzxi/RmxH+A771HdBVihN6kY/17NW8CN3A== X-Gm-Gg: ASbGncv6mH8GlqkuEbRLDMYN95G6ClubcRxizLMJvlyZBQjrSZBYTqjnKzT3+rmT45M QDCaQkTkIkD0TZYOOl0JweVfsw5xYH2U+ponDbJxKtYX3XUh0gvA6SdRWKGqNYj9/DV4lxP6oVm BrW3prVLS5AT4IKqzMTnDPshi8CwS8igfd019OmwypG/VsM42py/uJpRnKHwy7aln72b58Nlyup oUIZasml4+y6MGW+2ILEZE3PMWikB4GiE9CMbMyxU49/OAAM32hAbzAecjme+g4zo5eoWgtl1xd h8Nyv41rwYjtdjsW/9QRPzplm9kV4L1d7lEKWuFDkHs0 X-Google-Smtp-Source: AGHT+IHaNwjfE4BiooRO5RnZVihY9wkl7m5eA/Z9iDsnLl7cFIPdfIwFpOCtzDMH0cs1yNd2KapSmg== X-Received: by 2002:a05:6a00:180b:b0:736:baa0:2acd with SMTP id d2e1a72fcca58-73980487652mr23308076b3a.20.1743525303969; Tue, 01 Apr 2025 09:35:03 -0700 (PDT) Received: from localhost ([2601:646:9e00:f56e:123b:cea3:439a:b3e3]) by smtp.gmail.com with UTF8SMTPSA id d2e1a72fcca58-73970def69dsm9391964b3a.14.2025.04.01.09.35.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 01 Apr 2025 09:35:03 -0700 (PDT) From: Stanislav Fomichev To: netdev@vger.kernel.org Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com Subject: [PATCH net v5 07/11] docs: net: document netdev notifier expectations Date: Tue, 1 Apr 2025 09:34:48 -0700 Message-ID: <20250401163452.622454-8-sdf@fomichev.me> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250401163452.622454-1-sdf@fomichev.me> References: <20250401163452.622454-1-sdf@fomichev.me> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org We don't have a consistent state yet, but document where we think we are and where we wanna be. Signed-off-by: Stanislav Fomichev --- Documentation/networking/netdevices.rst | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/Documentation/networking/netdevices.rst b/Documentation/networking/netdevices.rst index ebb868f50ac2..6c2d8945f597 100644 --- a/Documentation/networking/netdevices.rst +++ b/Documentation/networking/netdevices.rst @@ -343,6 +343,29 @@ there are two sets of interfaces: ``dev_xxx`` and ``netif_xxx`` (e.g., acquiring the instance lock themselves, while the ``netif_xxx`` functions assume that the driver has already acquired the instance lock. +Notifiers and netdev instance lock +================================== + +For device drivers that implement shaping or queue management APIs, +some of the notifiers (``enum netdev_cmd``) are running under the netdev +instance lock. + +For devices with locked ops, currently only the following notifiers are +running under the lock: +* ``NETDEV_REGISTER`` +* ``NETDEV_UP`` + +The following notifiers are running without the lock: +* ``NETDEV_UNREGISTER`` + +There are no clear expectations for the remaining notifiers. Notifiers not on +the list may run with or without the instance lock, potentially even invoking +the same notifier type with and without the lock from different code paths. +The goal is to eventually ensure that all (or most, with a few documented +exceptions) notifiers run under the instance lock. Please extend this +documentation whenever you make explicit assumption about lock being held +from a notifier. + NETDEV_INTERNAL symbol namespace ================================