From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f178.google.com (mail-pf1-f178.google.com [209.85.210.178]) (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 614A3495C1 for ; Wed, 10 Jan 2024 18:28:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org 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="jFoV4c1K" Received: by mail-pf1-f178.google.com with SMTP id d2e1a72fcca58-6daf9d5f111so3019740b3a.0 for ; Wed, 10 Jan 2024 10:28:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1704911298; x=1705516098; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc:subject:date:message-id :reply-to; bh=6Y95rNNfwjLQzN9p1W2Wed8HGytubXo93i27+UvIZ5c=; b=jFoV4c1KLI65br0NuLRFqK2vF9+YvZ1//3oug/uTThFYzTkoSPjMqQ6zoAY943DXeR fXlzEezWDu4fH5TwXrBNfRpzWw6fFVugxXUMvfu+2YP84gq4gk/i+DtDq2wUjx3SZjlP ddZAJog1yne7RAThc7S4KSPy43Ll0ChBTlEZsDuC5M+D499IiuybgIRQz7ts1ppbGJw3 JtsFb/zt5EAosL5nne9gVt7k+mNy5KDLKo8GMgZKxKTWgs8ss65G9qh/0MJLNmnIO1b+ hsFsLkelLTDRDRGExGB0l75lB9cYu5NIF5Gb1+w77EZOFXh/UfRDmtnEavrtcVyBYOQA yDXw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1704911298; x=1705516098; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=6Y95rNNfwjLQzN9p1W2Wed8HGytubXo93i27+UvIZ5c=; b=EdgL/VmOnam54UV7m8DEGeccNMU1z05g5vliCDX/GUykm9NFaapGOYXOZyhvR7xrKP OJDbfh+PqichqI90SwZbEclpiiPw6gpYYLzCnAMo2Zb6P4FBdDzWrupvLuI3xh/Vb9hz eYlfwzC2/nsA6zIdaQKQsz9qPCWJAUCWcnt85cjR3KG9RY310ZcZuXi9SEvaI7vZzvW4 SKd1/evYLSr94YgtAVVOs9gF4uzlTP2TSMhJKp9WwTmYdLHulAiK9IXpoIpjn4AzOrxs uejr2FSAbnPH0WTXojyqd+3dyUHpT8uP6Qt3musmjhOfvrLXABpH6Vn0e69X/qwnrfwA MSMA== X-Gm-Message-State: AOJu0YzIVmFLorOB3SXr80cxfIA3/lNFHsGyqpwr9TKs5BcNGu5v8XJs hftXbaMOK9gJPnHyOWM/92g= X-Google-Smtp-Source: AGHT+IHMc7MWyNv1HudtNmoeI2ni2yWHYMUdCoYze8fxfk3HOpEgzZXbWPW84IpclSa6leK8REFCkQ== X-Received: by 2002:a05:6a00:8d86:b0:6d9:b7ef:466c with SMTP id im6-20020a056a008d8600b006d9b7ef466cmr26252pfb.67.1704911297630; Wed, 10 Jan 2024 10:28:17 -0800 (PST) Received: from localhost (dhcp-72-253-202-210.hawaiiantel.net. [72.253.202.210]) by smtp.gmail.com with ESMTPSA id fh12-20020a056a00390c00b006d0d90edd2csm3828088pfb.42.2024.01.10.10.28.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 10 Jan 2024 10:28:17 -0800 (PST) Sender: Tejun Heo Date: Wed, 10 Jan 2024 08:28:16 -1000 From: Tejun Heo To: gregkh@linuxfoundation.org Cc: andrea.righi@canonical.com, ast@kernel.org, linux-kernel@vger.kernel.org, geert@linux-m68k.org Subject: [PATCH v2 2/3] kernfs: Rearrange kernfs_node fields to reduce its size on 64bit Message-ID: References: <20240109214828.252092-1-tj@kernel.org> <20240109214828.252092-3-tj@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240109214828.252092-3-tj@kernel.org> From: Tejun Heo Subject: kernfs: Rearrange kernfs_node fields to reduce its size on 64bit Moving .flags and .mode right below .hash makes kernfs_node smaller by 8 bytes on 64bit. To avoid creating a hole from 8 bytes alignment on 32bit archs, .priv is moved below so that there are two 32bit pointers after the 64bit .id field. v2: Updated to avoid size increase on 32bit noticed by Geert. Signed-off-by: Tejun Heo Cc: Geert Uytterhoeven --- The third patch applies fine without update. include/linux/kernfs.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -206,22 +206,22 @@ struct kernfs_node { const void *ns; /* namespace tag */ unsigned int hash; /* ns + name hash */ + unsigned short flags; + umode_t mode; + union { struct kernfs_elem_dir dir; struct kernfs_elem_symlink symlink; struct kernfs_elem_attr attr; }; - void *priv; - /* * 64bit unique ID. On 64bit ino setups, id is the ino. On 32bit, * the low 32bits are ino and upper generation. */ u64 id; - unsigned short flags; - umode_t mode; + void *priv; struct kernfs_iattrs *iattr; };