From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 6CDD457CB6; Mon, 28 Oct 2024 00:54:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730076847; cv=none; b=LjvZ5ay+ackQaGAB7KTjs7zFG+mP5wHOlT+JdhL5GgBuKyi/nfVeumbxo8/T0jiGXRldhzkLZ91KnlI+HB0ToEUrOVLR3Xn0X4b8rO2y/LBlgxUUpoKtyQPLSKFqT8KsgQFsN1VQiY4mna8vk36uhy3KiDUd9R/2jyF1M6NffKk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730076847; c=relaxed/simple; bh=xf7zQQQESc2au6O1VjTOAPsuKbA5aTJVg3/4oNJ44jI=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=VFcN/2Nl6WghuDuXoHxJMJzvsg20noZZHgt7SHSlLmGbGzNoQHs3sjrPYFVrmOjD84qTIa3KalKKP1IUHBJplanG5kuXWRom9AZPUNeCIHuu7XwyrRnNOBjEx8uVUhAmKT1K24eTsCIse0g6PWEk2vef4ASmKSj+Y5WOX3zM0+k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=W1FVSYMh; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="W1FVSYMh" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:Message-ID:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type: Content-ID:Content-Description:In-Reply-To:References; bh=sHc9vh8NjTk1+qthHPP7uuKNqyJ0ng30sdvaF/oIbu8=; b=W1FVSYMhKOycXosnAsEeQjpH0J IPepPkkeXpsIosDe3SjbSQRK3LVMzHtvBg2BVyQafzGqHuwCGUJ7Y+g1XFnc3YvnmT9HjxwFpkaM/ CZmUShoOmVL/txWTXdoxZr38/NOGfOB8n5iqvIfbGF1fWTgpfc7NedSxtMsMZ/9x8balxvDhquqS6 LXUSrEduJqP1lpYy2nhhDJFqdv3SaCivrAqfZ0H/Rnd8fc3Rzw25Gyrkk8kY8f08yaS5kFj9miVD5 TVEe+Swl1hjSwZmUma3Lk7wGId3WsnnNPhxEoTvnFz+VvlkTnOq5DQILMi/nRzj9/+k085LzPAn1F M8RhzwLQ==; Received: from [50.53.2.24] (helo=bombadil.infradead.org) by bombadil.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1t5E19-00000009AbQ-0tmQ; Mon, 28 Oct 2024 00:53:59 +0000 From: Randy Dunlap To: linux-doc@vger.kernel.org Cc: patches@lists.linux.dev, Randy Dunlap , Jonathan Corbet Subject: [PATCH] Documentation: admin: reorganize kernel-parameters intro Date: Sun, 27 Oct 2024 17:53:56 -0700 Message-ID: <20241028005356.214369-1-rdunlap@infradead.org> X-Mailer: git-send-email 2.47.0 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Reorganize the introduction to the kernel-parameters file to place related paragraphs together: - move module info together and near the beginning - add a Special Handling section for dashes, underscores, double quotes, cpu lists, and KMG suffixes - add a Kernel Build Options section Signed-off-by: Randy Dunlap Cc: Jonathan Corbet --- Documentation/admin-guide/kernel-parameters.rst | 35 ++++++++------ 1 file changed, 22 insertions(+), 13 deletions(-) --- linux-next-20241025.orig/Documentation/admin-guide/kernel-parameters.rst +++ linux-next-20241025/Documentation/admin-guide/kernel-parameters.rst @@ -27,6 +27,16 @@ kernel command line (/proc/cmdline) and when it loads a module, so the kernel command line can be used for loadable modules too. +This document may not be entirely up to date and comprehensive. The command +"modinfo -p ${modulename}" shows a current list of all parameters of a loadable +module. Loadable modules, after being loaded into the running kernel, also +reveal their parameters in /sys/module/${modulename}/parameters/. Some of these +parameters may be changed at runtime by the command +``echo -n ${value} > /sys/module/${modulename}/parameters/${parm}``. + +Special handling +---------------- + Hyphens (dashes) and underscores are equivalent in parameter names, so:: log_buf_len=1M print-fatal-signals=1 @@ -39,8 +49,8 @@ Double-quotes can be used to protect spa param="spaces in here" -cpu lists: ----------- +cpu lists +~~~~~~~~~ Some kernel parameters take a list of CPUs as a value, e.g. isolcpus, nohz_full, irqaffinity, rcu_nocbs. The format of this list is: @@ -82,12 +92,16 @@ so that "nohz_full=all" is the equivalen The semantics of "N" and "all" is supported on a level of bitmaps and holds for all users of bitmap_parselist(). -This document may not be entirely up to date and comprehensive. The command -"modinfo -p ${modulename}" shows a current list of all parameters of a loadable -module. Loadable modules, after being loaded into the running kernel, also -reveal their parameters in /sys/module/${modulename}/parameters/. Some of these -parameters may be changed at runtime by the command -``echo -n ${value} > /sys/module/${modulename}/parameters/${parm}``. +KMG suffixes +~~~~~~~~~~~~ + +The [KMG] suffix is commonly described after a number of kernel +parameter values. These 'K', 'M', and 'G' letters represent the _binary_ +multipliers 'Kilo', 'Mega', and 'Giga', equaling 2^10, 2^20, and 2^30 +bytes respectively. Such letter suffixes can also be entirely omitted. + +Kernel Build Options +-------------------- The parameters listed below are only valid if certain kernel build options were enabled and if respective hardware is present. This list should be kept @@ -212,10 +226,5 @@ a fixed number of characters. This limit and is between 256 and 4096 characters. It is defined in the file ./include/uapi/asm-generic/setup.h as COMMAND_LINE_SIZE. -Finally, the [KMG] suffix is commonly described after a number of kernel -parameter values. These 'K', 'M', and 'G' letters represent the _binary_ -multipliers 'Kilo', 'Mega', and 'Giga', equaling 2^10, 2^20, and 2^30 -bytes respectively. Such letter suffixes can also be entirely omitted: - .. include:: kernel-parameters.txt :literal: